Skin provides an elastic, self-regenerating, protective covering for the body. The skin and its appendages are the primary means by which we are viewed in the world and physical appearances are often important to the well-being of patients. Examination of the skin, hair, and nails is performed as part of both the comprehensive and focused physical examination. The skin, hair, and nails can provide external visible clues to systemic disease that may not otherwise be apparent.
Skin
- 1.
Systematically inspect the entire skin surface. During evaluation of each organ system, evaluate the overlying skin for:
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Color
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Uniformity
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Thickness
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Symmetry
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Hygiene
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Lesions
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Odors
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- 2.
Palpate skin surfaces for:
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Moisture
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Temperature
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Texture
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Turgor (fullness or tension produced by the fluid content of the cells and tissue)
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Elasticity
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Hair
- 1.
Inspect hair for:
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Color
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Distribution
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Density
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- 2.
Palpate hair for texture and fragility
Nails
- 1.
Inspect for:
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Pigmentation of nail plates and nail beds
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Length
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Symmetry
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Surface changes (ridging, beading, pitting, peeling)
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- 2.
Inspect and palpate proximal and lateral nail folds for:
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Redness
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Swelling
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Pain
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Exudate
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Growths (warts, cysts, tumors)
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Shape of lunulae
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- 3.
Palpate nail plate for:
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Texture
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Firmness
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Thickness
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Uniformity
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Adherence to nail bed
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- 4.
Measure nail base angle
- 5.
Observe the cuticles for:
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Color
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Vasculature
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Integrity
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Anatomy and Physiology
The skin is a stratified organ composed of several functionally related layers. Fig. 9.1 shows the main structural components and their approximate spatial relationships. The anatomy of the skin does vary from one part of the body to another.
Skin structure and physiologic processes perform the following integral functions:
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Protect against microbial and foreign substance invasion and minor physical trauma
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Restrict body fluid loss by providing a restrictive barrier
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Regulate body temperature
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Provide sensory perception via free nerve endings and specialized receptors
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Produce vitamin D from precursors in the skin
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Contribute to blood pressure regulation through constriction of skin blood vessels
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Repair surface wounds by exaggerating the normal process of cell replacement
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Excrete sweat, urea, and lactic acid
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Express emotions
Epidermis
The epidermis is the outermost portion of the skin and is composed of several cellular layers. The topmost layer is the stratum corneum (cornified layer), which is composed of closely packed, dead, keratin-filled squamous cells, which is the chief mechanical barrier protecting the body against environmental exposures, pathogens, and restricting water loss. The keratins that are contained in the stratum corneum are synthesized in the lower layers of the skin, beginning at the basal layer, which also contains the stem cells, which allow for the regenerative properties of the skin. As keratinocytes mature, they pass from the basal layer through the granular and spinous layers to the cornified layer, a process that takes 28 days.
The thick skin of the palms and soles contains an additional layer compared with other parts of the body called the stratum lucidum, which lies just below the stratum corneum. Mucosal skin on the other hand, lacks a stratum corneum, allowing for diffusion through the skin surface. The stratum basale also contains melanocytes, the cells that synthesize melanin, which gives the skin its color.
Dermis
The dermis is the richly vascular connective tissue layer of the skin that supports and separates the epidermis from adipose tissue. Interdigitating papillae secure the epidermis to the dermis and provide nourishment for the epidermal cells. Elastin, collagen, and reticular fibers provide resilience, strength, and stability. Sensory nerve fibers located in the dermis form a complex network to provide sensations of pain, touch, and temperature. The dermis also contains autonomic motor nerves that innervate blood vessels, glands, and the arrector pili muscles.
Hypodermis
The dermis is connected to underlying tissue by the hypodermis, a subcutaneous layer that consists of loose connective tissue filled with adipose. This adipose layer generates heat and provides insulation, shock absorption, and a reserve of calories.
Appendages
Cutaneous appendages are outgrowths of the skin and include eccrine sweat glands, apocrine sweat glands, sebaceous glands, hair, and nails.
The eccrine sweat glands open directly onto the surface of the skin and help regulate body temperature through sweat secretion. These glands are distributed throughout the body except at the lip margins, eardrums, nail beds, inner surface of the prepuce, and glans penis.
The apocrine glands are specialized structures found only in the axillae, nipples, areolae, anogenital area, eyelids, and external ears. Apocrine glands secrete an oily fluid containing protein, carbohydrate, and other substances. Secretions from these glands are odorless; body odor is produced by bacterial decomposition of apocrine sweat.
The sebaceous glands secrete sebum, a lipid-rich substance that acts as a lubricant and moisturizer for skin and hair. Secretory activity, which is stimulated by sex hormones (primarily testosterone), varies according to hormonal levels throughout life.
A hair consists of a root and a shaft, which sit in a follicle. At the base of the follicle the papilla contains a loop of capillaries supplying nourishment for growth. Melanocytes in the follicle synthesize pigment giving hair its color. Adults have both vellus and terminal hair. Vellus hair is short, fine, soft, and nonpigmented. Terminal hair is coarser, longer, thicker, and usually pigmented. Each hair goes through cyclic changes: anagen (growth), catagen (atrophy), and telogen (rest), after which the hair is shed (exogen). Males and females have about the same number of hair follicles with differential stimulation by hormones. The shape of the hair follicle directly relates to the shape of the hair itself (straight versus curly). This shape does vary by race and ethnicity.
The nails are appendages of the skin, which are composed of epidermal cells converted to hard plates of keratin. They protect the fingertips and are important in dexterity. The nail plate sits on the highly vascular nail bed which lies on periosteum. The white crescent-shaped area extending beyond the proximal nail fold marks the end of the nail matrix, the site of nail growth. The layer of skin covering the nail root is the cuticle, or eponychium, which pushes up and over the lower part of the nail body. The paronychium is the soft tissue surrounding the nail border ( Fig. 9.2 ).
Infants and Children
The skin of infants and children is smoother than that of adults, due to the absence of coarse terminal hair and less exposure to the elements, particularly the sun. Desquamation of the stratum corneum may be present at birth or very shortly after. It may vary from mild flakiness to course shedding of large sheets of skin. Postterm infants often have cracked, peeling skin. Vernix caseosa, a mixture of sebum and cornified epidermis, covers the infant’s body at birth. The subcutaneous fat layer is poorly developed in newborns, predisposing them to hypothermia. The newborn’s body, particularly the shoulders and back, can be covered with fine, silky hair called lanugo. More commonly seen in preterm infants, this hair is shed within 10 to 14 days. Some newborns are bald, whereas others have a large amount of head hair. Most of the hair is shed by about 2 to 3 months of age, to be replaced by more permanent hair with a new texture and often a different color.
The eccrine sweat glands begin to function after the first month of life, whereas apocrine function does not begin until puberty, thus children lack offensive perspiration.
Adolescents
During adolescence, the apocrine glands enlarge and become active, causing increased axillary sweating and sometimes body odor. Sebaceous glands increase sebum production in response to increased hormone levels, primarily androgen, giving the skin an oily appearance and predisposing the individual to acne.
Coarse terminal hair appears in the axillae and pubic areas of both female and male adolescents and on the face of males. Hair production is one response to changing androgen levels. Refer to Chapter 8 for a more thorough discussion of maturational changes during adolescence.
Pregnant Patients
Increased blood flow to the skin, especially to the hands and feet, results from peripheral vasodilation and increased numbers of capillaries. Acceleration of sweat and sebaceous gland activity occurs. Both processes assist in dissipating the excess heat caused by increased metabolism during pregnancy. Spider angiomas and cherry hemangiomas that are present may increase in size.
The skin thickens, and fat is deposited in the subdermal layers. Because of increased fragility of connective tissues, separation may occur with stretching. Most pregnant patients have some degree of increased pigmentation that is seen on the face, nipples, areolae, axillae, vulva, perianal skin, and umbilicus. During pregnancy, nevi may grow, change color, and new nevi may appear.
Older Adults
Sebaceous and sweat gland activity decreases in older adults, and as a result, the skin becomes drier with less perspiration produced. With aging and increased sun exposure, the epidermis thins and becomes more fragile, with decreased resistance to trauma. Epidermal permeability is increased, reducing the efficiency of the barrier function of the stratum corneum causing skin to become dry.
Aging and sun exposure also contribute to decreasing elasticity and collagen loss in the dermis. The dermis shrinks, causing the epidermis to fold and become wrinkled. This effect is increased in whites, who have an earlier onset and greater skin wrinkling and sagging signs than darker races ( Rawlings, 2006 ).
Subcutaneous tissues also decrease, particularly in the extremities, giving joints and bony prominences a sharp, angular appearance. The hollows in the thoracic, axillary, and supraclavicular regions deepen.
Gray hair results from a decrease in the number of functioning melanocytes. Similarly, nevi also regress and disappear. Axillary and pubic hair production declines because of a reduction in hormones. The density and rate of scalp hair growth (anagen phase) decline with age. The size of hair follicles also changes, and terminal scalp hair progressively transitions into vellus hair, causing age-associated baldness in both men and women. The opposite transition, from vellus to terminal, occurs in the hair of the nares and on the tragus of men’s ears. Women produce increased coarse facial hair because of higher androgen-estrogen ratios. Both genders experience overall loss of hair from the trunk and extremities. Peripheral extremity hair loss may also occur when peripheral vascular disease is present.
Nail growth slows and nails become more brittle because of decreased peripheral circulation. The nails, particularly the toenails, become thick, brittle, hard, and yellowish. They develop longitudinal ridges and are prone to splitting into layers.
Review of Related History
For each of the symptoms or conditions discussed in this section, targeted topics to include in the history of the present illness are listed. Responses to questions about these topics provide clues for focusing the physical examination and developing an appropriate diagnostic evaluation. Questions regarding medication use (prescription and over the counter preparations) as well as complementary and alternative therapies are relevant for each.
History of Present Illness
Skin
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Changes in skin: dryness, pruritus, sores, rashes, lumps, color, texture, odor, amount of perspiration; changes in wart or mole; lesion that does not heal or is chronically irritated (see Risk Factors boxes )
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Temporal sequence: date of initial onset; time sequence of occurrence and development; sudden or gradual onset; date of recurrence, if any
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Symptoms: itching, pain, exudate, bleeding, color changes, seasonal or climate variations
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Location: skinfolds, extensor or flexor surfaces, localized or generalized, sun exposed or protected, mucosal involvement
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Associated symptoms: presence of systemic disease or fever, relationship to stress or leisure activities
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Recent exposure to environmental or occupational toxins or chemicals, new skin or personal care products, new household cleaning products (aerosols)
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Recent exposure to persons with similar skin condition
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Apparent cause of problem, patient’s perception of cause
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Travel history: where, when, length of stay, exposure to diseases, contact with travelers
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What the patient has been doing for the problem, response to treatment, what makes the condition worse or better
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How the patient is adjusting to the problem
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Medications: antibiotics, any new medications, topical preparations to treat—steroids, antifungals
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Exposure to sunlight or ultraviolet radiation (UVA and UVB) including
- •
Severe blistering sunburns, even as a child
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Indoor tanning device usage
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Geographic exposure (people who live in areas that get large amounts of UV radiation from the sun, e.g., higher altitude)
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- •
Previous personal history of melanoma
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Family history of melanoma (first-degree relative)
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Moles
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Dysplastic or atypical nevi
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Large congenital nevus (>15 cm)
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Immune suppression
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Skin type, relative inability to tan (Skin types, Box 9.1 )
You can use the National Cancer Institute’s Melanoma Risk Assessment Tool to estimate a person’s absolute risk of developing invasive melanoma at: https://www.cancer.gov/melanomarisktool
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Age (older than 50 years)
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Exposure to sunlight or ultraviolet radiation (UVA and UVB)
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Indoor tanning device usage
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Blistering sunburns
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Chronic and cumulative exposure—squamous cell carcinoma
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Intermittent exposure—basal cell carcinoma
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Geographic location: near equator or at high altitudes
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- •
Skin type, relative inability to tan (see Skin Type, Box 9.1 )
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Exposure to arsenic, creosote, coal tar, and/or petroleum products
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Overexposure to radium, radioisotopes, or x-rays
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Repeated trauma or irritation to skin
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Precancerous dermatoses
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Large scars
People burn or tan depending on their skin type, the time of year, and how long they are exposed to UV rays. The six types of skin, based on how likely it is to tan or burn, are as follows:
I: Always burns, never tans, sensitive to UV exposure
II: Burns easily, tans minimally
III: Burns moderately, tans gradually to light brown
IV: Burns minimally, always tans well to moderately brown
V: Rarely burns, tans profusely to dark
VI: Never burns, deeply pigmented, least sensitive
Although everyone’s skin can be damaged by UV exposure, people with skin types I and II are at the highest risk.
Hair
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Changes in hair: loss or growth, distribution, texture, color
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Occurrence: sudden or gradual onset, symmetric or asymmetric pattern, recurrence
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Associated symptoms: pain, itching, lesions, presence of systemic disease or high fever, recent stress, hair-pulling, infection
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Exposure to drugs, environmental or occupational toxins or chemicals, commercial hair care chemicals
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Nutrition: dietary changes, dieting
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What the patient has been doing for the problem, response to treatment, what makes the problem worse or better
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How the patient is adjusting to the problem
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Medications: drugs or preparations for hair loss (minoxidil, finasteride, dihydrotestosterone [DHT] inhibitors)
Nails
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Changes in nails: splitting, breaking, discoloration, ridging, thickening, markings, separation from nail bed
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Recent history: systemic illness, high fever, trauma, stress, biting
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Associated symptoms: pain, swelling, exudate
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Temporal sequence: sudden or gradual onset, relationship to injury of nail or finger
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Recent exposure to drugs, environmental or occupational toxins or chemicals; frequent immersion in water
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What the patient has been doing for the problem, response to treatment, what makes the problem worse or better
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Medications: chemotherapy (taxanes, anthracyclines), psoralens, retinoids, tetracyclines, antimalarials
Past Medical History
Skin
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Previous skin problems: sensitivities, allergic skin reactions, skin disorders (e.g., atopic dermatitis), congenital or acquired lesions, treatment
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Tolerance to sunlight ( Box 9.1 )
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Diminished or heightened sensitivity to touch
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Cardiac, respiratory, liver, endocrine, or other systemic diseases
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Hair
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Previous hair problems: loss, thinning, unusual growth or distribution, brittleness, breakage, treatment
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Systemic problems: thyroid disorder, rheumatologic disease, any severe illness, malnutrition, associated skin disorder
Nails
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Previous nail problems: injury; bacterial, fungal, or viral infection
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Systemic problems: associated skin disorder; congenital anomalies; respiratory, cardiac, endocrine, hematologic, or other systemic disease
Family History
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Current or past dermatologic diseases or disorders in family members; melanoma; dermatoses (e.g., psoriasis); infestations; bacterial, fungal, or viral infections
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Allergic hereditary diseases such as asthma or allergic rhinitis
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Familial hair loss or pigmentation patterns
Personal and Social History
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Skin care habits: cleansing routine; soaps, oils, emollients, or local applications used; cosmetics; home remedies or preparations used; sun exposure patterns and history; sunburn history; use of sunscreen agents; recent changes in skin care habits (see Patient Safety, “Sunscreen” )
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Skin self-examination ( Box 9.2 )
Box 9.2
Patient Instructions for Skin Self-Examination
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Always use a good light, positioned to minimize distracting glare. Look for a new growth or any skin change.
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Be aware of the locations and appearance of moles and birthmarks.
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Examine your back and other hard-to-see areas of the body using full-length and handheld mirrors. Ask a friend or relative to help inspect those areas that are difficult to see, such as the scalp and back.
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Begin with your face and scalp using one or more mirrors. Proceed downward, focusing on neck, chest, and torso. Patients, check under breasts. With back to the mirror, use hand mirror to inspect back of neck, shoulders, upper arms, back, buttocks, legs. Concentrate especially on areas where dysplastic nevi (those with unexpected changes) are most common—the shoulders and back; and areas where ordinary moles are rarely found—the scalp, breast, and buttocks. Check hands, including nails. In a full-length mirror, examine elbows, arms, underarms. Sitting down, check legs and feet, including soles, heels, nails, and between the toes. Use a hand mirror to examine genitals. See rather than feel any early signs of a mole change. Use a cell phone to take photos of moles and compare the photographs of the same moles over a period of several months. Monitor change in size by measuring. It can be done simply with a small ruler or even by comparing the moles to the size of your thumb or fingernail.
- •
Consult your healthcare provider promptly if any pigmented skin spots look like melanoma, if new moles have appeared, or if any existing moles have changed. See also the ABCDE changes in moles (Melanoma, in Abnormalities).
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- •
Hair care habits: cleansing routine, shampoos and oils and moisturizers, coloring preparations used, permanents, applied heat, hair straightening, extensions, recent changes in hair care habits. Note that hair care practices can vary by race and hair type.
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Nail care habits: any difficulty in clipping or trimming nails, instruments used; biting nails; use of artificial nail overlays
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Exposure to environmental or occupational hazards: dyes, chemicals, plants, toxic substances, frequent immersion of hands in water, frequent sun exposure
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Recent psychological or physiologic stress
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Use of alcohol, tobacco
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Sexual history: sexually transmitted infections (syphilis, gonorrhea, human immunodeficiency virus [HIV])
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Use of recreational drugs
Do you ask if your patients use sunscreen? Keep this in mind when they respond: Skin should be the same color all year long. Those who use sunscreen with a protection factor of 30 or higher are still at risk for significant sunburn. Why? People often don’t use enough sunscreen. They think they are protected, but they are in fact getting significant UV exposure. It is necessary to apply sunscreen generously (about 1 shot glass full over entire body) and frequently. Apply minutes before exposure and then reapply after swimming, or bathing and every 2 to 3 hours of exposure.
Other recommendations include:
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Do not sunbathe.
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Avoid unnecessary sun exposure, especially between 10:00 am and 4:00 pm , the peak hours for harmful ultraviolet (UV) radiation.
- •
When exposed to sunlight, wear protective clothing such as long pants, long-sleeved shirts, broad-brimmed hats, and UV-protective sunglasses. Look for SPF-containing clothing, which offers the benefit of not needing reapplication.
- •
Never use tanning booths.
- •
Teach children good sun protection habits at an early age: the damage that leads to adult skin cancers starts in childhood.
Infants
- •
Feeding history: breast or formula, type of formula, what foods introduced and when (see Clinical Pearl, “Carotenemia” )
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Diaper history: type of diapers used, skin cleansing routines, and methods of cleaning
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Types of clothing and washing practices: soaps and detergents used, new blanket or clothing
- •
Bathing practices: frequency, types of soap, oils, shampoos or emollients used
- •
Dress habits: amount and type of clothing in relation to environmental temperature
- •
Temperature and humidity of the home environment: air conditioning, heating system (drying or humidified)
Carotenemia, or xanthoderma, common in infants who have started eating baby foods, is yellow pigmentation of the skin and increased beta-carotene levels in the blood. Carotenemia does not cause orange discoloration of the sclerae, and thus is usually easy to distinguish from jaundice. In most cases, this benign condition follows increased consumption of carotene-rich foods, such as carrots, squash, and sweet potatoes. If parental anxiety is high, provide reassurance and counsel that after discontinuation of carotene-rich foods, the skin color will normalize in weeks to months.
Children and Adolescents
- •
Eating habits and types of food
- •
Food allergies. Note that food allergies do not classically cause eczema.
- •
Exposure to infectious diseases at day care, school: impetigo; viruses that produce skin rashes (Coxsackie); measles, mumps, rubella, varicella in unvaccinated children
- •
Allergic disorders: eczema, urticaria, pruritus, hay fever, asthma, other chronic respiratory disorders
- •
Pets or animal exposure
- •
Outdoor exposures such as play areas, hiking, camping, picnics, gardening
- •
Skin injury history: frequency of falls, cuts, abrasions; repeated history of unexplained injuries
- •
Chronic hair-pulling or manipulation
- •
Nail-biting
Pregnant Patients
- •
Weeks of gestation or postpartum
- •
Hygiene practices
- •
Presence of skin problems before pregnancy (e.g., acne may worsen)
- •
Effects of pregnancy on preexisting conditions (e.g., autoimmune disorders may remit; condylomata acuminata commonly become larger and more numerous)
Older Adults
- •
Increased or decreased sensation to touch or to the environment
- •
Generalized chronic itching; exposure to skin irritants, detergents, lotions (any moisturizer that comes in a pump has a high alcohol content), woolen clothing, humidity of environment
- •
Susceptibility to skin infections
- •
Healing response: delayed or interrupted
- •
Frequent falls resulting in multiple cuts or bruises
- •
Risk for pressure ulcers secondary to immobilization or nonambulatory status
- •
History of chronic medical conditions (e.g., diabetes mellitus, vascular disease)
- •
Medications and polypharmacy
Examination and Findings
Equipment
- •
Centimeter ruler (flexible, clear)
- •
Flashlight or penlight
- •
Handheld magnifying lens or dermatoscope
- •
Wood’s lamp (to view fluorescing or depigmented lesions)
Skin
Use inspection and palpation to examine the skin. The most important tools are your own eyes and powers of observation. When gross inspection leaves you uncertain, sometimes a handheld magnifying glass or dermatoscope may help.
Inspection
Adequate lighting is essential. Direct, overhead lighting should be used when examining patients. Inadequate lighting can result in inadequate assessment. Tangential lighting is helpful in assessing contour.
Although the skin is commonly observed as each part of the body is examined, it is important to make a brief but careful overall visual sweep of the entire body. This “bird’s-eye view” gives a good idea of the distribution, extent, and symmetry of any lesions. It also allows for identification of “ugly duckling” lesions that stand out. The gross view will allow the practitioner to know where to pay particular attention during the remainder of the examination ( Box 9.3 ).
The use of certain traditional health practices by various cultural groups can produce cutaneous manifestations that could be wrongly confused with disease or physical abuse. Two such practices are “coining” and “cupping” as used by some Asian subcultures. In coining, a coin dipped in mentholated oil is vigorously rubbed across the skin in a prescribed manner, causing a mild dermabrasion. This practice is believed to release excess force from the body and hence restore balance. In cupping, a series of small, heated glasses are placed on the skin, forming a suction that leaves a red or purpuric circular mark, drawing out the bad force. The skin markings may alarm the healthcare provider who is unaware of such practices. The lesson: in the history, ask about home remedies or practices.
Adequate exposure of the skin is necessary. It is essential to remove clothing and to fully remove drapes or coverings as each section of the body is examined. Make sure that the room temperature is comfortable. Look carefully at all areas, remembering to inspect areas that are usually not exposed, such as the axillae, buttocks, perineum, backs of thighs, and inner upper thighs. Remove shoes and socks to look at the feet. Pay careful attention to intertriginous surfaces (areas where two skin surfaces may touch, e.g., axillae and groin), especially in infants, older adults and bedridden patients. As you complete the examination for each area, redrape or cover the patient. When inspecting the skin, it is important to have a systematic routine in place to ensure that no areas are forgotten. Skin thickness varies over the body, with the thinnest skin on the eyelids and the thickest at areas of pressure or rubbing, most notably the soles, palms, and elbows. Note calluses on the hands or feet. Look for corns on pressure points. Corns are flat or slightly elevated, circumscribed, painful lesions with a smooth, hard surface ( Fig. 9.3 ). A superficial area of hyperkeratosis is called a callus. Calluses usually occur on the weight-bearing areas of the feet and on the palmar surface of the hands. Calluses are less well demarcated than corns and are usually not tender ( Fig. 9.4 ).
The range of expected skin color varies from dark brown to white with pink or yellow overtones. Although color should assume an overall uniformity, there is often pigment variation that may be sun related, trauma induced, or simply normal (e.g., knuckles may be darker in dark-skinned patients). Callused areas may appear yellow. Vascular flush areas (e.g., cheeks, neck, upper chest, and genital area) may appear pink or red, especially with anxiety or excitement. Be aware that skin color may be masked by cosmetics and tanning agents. Look for localized areas of discoloration.
Individuals with dark skin may show pigmentary demarcation lines. These lines, a normal variation, mark the border between deeply pigmented skin and lighter pigmented skin. They are most commonly seen on the arms, legs, chest, and back and have been reported most often in black and Japanese populations. Accentuation of preexisting lines or appearance of new lines may occur during pregnancy.
Nevi (moles) occur in forms that vary in size and degree of pigmentation. Nevi are present on most persons regardless of skin color, and may occur anywhere on the body. They may be flat, raised, dome-shaped, smooth, rough, or hairy. Their color ranges from pink, tan, gray, and shades of brown to black. Table 9.1 describes the features and occurrence of various types of pigmented nevi.
| TYPE | FEATURES | OCCURRENCE | COMMENTS |
|---|---|---|---|
| Halo nevus | Sharp, oval, or circular; depigmented halo around mole; may undergo many morphologic changes; usually disappears and halo repigments (may take years) | Usually on back in young adult | Usually benign; biopsy indicated because same process can occur around melanoma |
| Intradermal nevus | Dome-shaped; raised; flesh to black color; may be pedunculated or hair bearing | Cells limited to dermis | No indication for removal other than cosmetic |
| Junction nevus | Flat or slightly elevated; dark brown | Nevus cells lining dermoepidermal junction | Should be removed if exposed to repeated trauma |
| Compound nevus | Slightly elevated brownish papule: indistinct border | Nevus cells in dermis and lining dermoepidermal junction | Should be removed if exposed to repeated trauma |
| Hairy nevus | May be present at birth; may cover large area; hair growth may occur after several years | Should be removed if changes occur |
Nevi occur more often in lighter-skinned than in darker-skinned individuals. There is a strong association between sun exposure and the number of nevi. They increase in number throughout infancy and childhood, with peak incidence in the fourth to fifth decades. Nevi involute and diminish in number with advancing age.
Although most nevi are harmless, some may be dysplastic or develop into melanoma. Of note, the term “atypical” denotes the clinical appearance whereas dysplastic is a histologic term. Table 9.2 describes differences in the features of normal and atypical moles. Atypical nevi tend to occur on heavily sun damaged skin, classically upper back in men and on the legs in women ( Box 9.4 “Atypical Mole or Melanoma?”).
| FEATURE | NORMAL MOLE | DYSPLASTIC MOLE |
|---|---|---|
| Color | Uniformly tan or brown; all moles on one person tend to look alike | Mixture of tan, brown, black, and red/pink; moles on one person often do not look alike |
| Shape | Round or oval with a clearly defined border that separates the mole from surrounding skin | Irregular borders may include notches; may fade into surrounding skin and include a flat portion level with skin |
| Surface | Begins as flat, smooth spot on skin; becomes raised; forms a smooth bump | May be smooth, slightly scaly, or have a rough, irregular, “pebbly” appearance |
| Size | Usually less than 6 mm (size of a pencil eraser) | Often larger than 6 mm and sometimes larger than 10 mm |
| Number | Typical adult has 10-40 moles scattered over the body | Many persons do not have increased number; however, persons severely affected may have more than 100 moles |
| Location | Usually above the waist on sun-exposed surfaces of the body; scalp, breast, and buttocks rarely have normal moles | May occur anywhere on the body, but most commonly on back; may also appear below the waist and on scalp, breast, and buttocks |
Dysplastic nevi (atypical moles) occur predominantly on the trunk. They tend to be large, usually greater than 5 mm, with a flat component. The border is typically ill defined. The shape can be round, oval, or irregular. The color is usually brown but can be mottled with dark brown, pink, and tan. Some individuals have only 1 to 5 moles; others have more than 100.
In melanoma, the border is more irregular. Lesions tend to be larger, often greater than 6 mm. Color variation within the lesion is characteristic, ranging from tan-brown, dark brown, or black to pink, red, gray, blue, or white.
Any lesion suggestive of a melanoma must be biopsied. Individuals with dysplastic moles are at increased risk for melanoma.
Several variations in skin color occur in almost all healthy adults and children, including nonpigmented striae (i.e., silver or pink “stretch marks” that occur during pregnancy or weight gain), freckles in sun-exposed areas, birthmarks, and nevi ( Fig. 9.5 ). Adult women (and sometimes men) will commonly have melasma (see Fig. 9.34 ), areas of hyperpigmentation on the face and neck that are associated with pregnancy or hormonal variation. This condition is more noticeable in darker-skinned patients. The absence of melanin produces patches of unpigmented skin or hair, such as with vitiligo ( Fig. 9.6 ).
Alterations in color in dark-skinned persons are best seen in the sclera, conjunctiva, buccal mucosa, tongue, lips, nail beds, and palms. Particular variations in skin color may be the result of physiologic pigment distribution. The palms and soles are lighter in color than the rest of the body and should be assessed when concerned for diffuse skin changes such as erythroderma, which is an intense, widespread reddening of the skin. Hyperpigmented nevi on the palms and soles of the feet are common in darker skinned patients. Freckling of the buccal cavity, gums, and tongue commonly occurs and is benign. The sclera may appear yellowish brown (often described as “muddy”) or may contain brownish pigment that resemble moles. A bluish hue of the lips and gums can be a normal finding in persons with dark skin. Some dark-skinned persons have very blue lips, giving a false impression of cyanosis.
Systemic disorders can produce generalized or localized color changes; these are described in Table 9.3 . Localized redness often results from an inflammatory process. Pale, shiny skin of the lower extremities may reflect peripheral changes that occur with systemic diseases such as diabetes mellitus and peripheral vascular disease. Injury, steroids, vasculitis, stasis, and several systemic disorders can cause localized hemorrhage into the skin, producing red-purple discolorations. Bleeding into the skin results in ecchymoses (i.e., bruising); pinpoint bleeding from capillaries occurs is called petechiae (smaller than 0.5 cm in diameter) ( Fig. 9.7 ) or purpura (larger than 0.5 cm in diameter) ( Fig. 9.8 ). Vascular skin lesions are characterized in Fig. 9.9 (see Clinical Pearl, “Telangiectasias: Capillary Spider/Spider Angioma” ). Box 9.5 describes some characteristic odors that you may note as you examine the skin.
Telangiectasias are permanently dilated, small blood vessels consisting of venules, capillaries, or arterioles. How do you tell the difference between a capillary spider and a spider angioma? Capillary spiders are little masses of venules. When you blanch them, they will refill in an erratic, not-at-all-organized way. Spider angiomas are arterial. Blanch the center, and they will refill in a very organized way, from the center out and evenly in all directions (see Fig. 9.9 ).
| COLOR | CAUSE | DISTRIBUTION | SELECT CONDITIONS |
|---|---|---|---|
| Brown | Darkening of melanin pigment | Generalized | Pituitary, adrenal, liver disease |
| Localized | Nevi, neurofibromatosis | ||
| White | Absence of melanin | Generalized | Albinism |
| Localized | Vitiligo | ||
| Red (erythema) | Increased cutaneous blood flow | Localized | Inflammation |
| Generalized | Fever, viral exanthem, urticaria | ||
| Increased intravascular red blood cells | Generalized | Polycythemia | |
| Yellow | Increased bile pigmentation (jaundice) | Generalized | Liver disease |
| Increased carotene pigmentation | Generalized (except sclera) | Hypothyroidism, increased intake of vegetables containing carotene | |
| Blue | Increased unsaturated hemoglobin secondary to hypoxia | Lips, mouth, nail beds | Cardiovascular and pulmonary diseases |
Even the skin may have odors suggesting a variety of problems: infectious, metabolic, or neurologic. Sweatiness intensifies the smell.
| CAUSE OF ODOR | TYPE OF ODOR |
|---|---|
| Clostridium gas gangrene | Rotten apples |
| Proteus infection | Mousy |
| Pseudomonas infection (especially burns) | Grapelike |
| Tuberculous lymphadenitis (scrofula) | Stale beer |
| Anaerobic infection; scurvy | Putrid |
| Intestinal obstruction, peritonitis | Feculent |
| Phenylketonuria | Mousy, musty |
Palpation
As you inspect, palpate the skin for moisture, temperature, texture, turgor, and elasticity. Palpation may yield additional data for describing lesions, particularly in relation to elevation or depression.
Minimal perspiration or oiliness should be present. Increased perspiration may be associated with activity, warm environment, obesity, anxiety, or excitement; it may be especially noticeable on the palms, scalp, forehead, and in the axillae. The intertriginous areas or skin in body folds may also be damp leading to development of intertrigo ( Fig. 9.10 ).
The skin should range from cool to warm to the touch. Use the dorsal surface of your hands or fingers because these areas are most sensitive to temperature perception. At best, this assessment is a rough estimate of skin temperature; what you are really looking for is bilateral symmetry. Environmental conditions, including the temperature of the examining room, as well as body location may affect surface temperature.
The texture should feel smooth, soft, and even. Roughness on exposed areas or areas of pressure (particularly the elbows, soles, and palms) may be caused by dry skin or irritation. Extensive or widespread roughness may be the result of a keratinization disorder or damaged skin. Hyperkeratoses, especially of the palms and soles, may be the sign of a systemic disorder such as exposure to arsenic, other toxins, or a sign of internal malignancy.
Assessment of skin elasticity can be helpful to detect certain conditions. Gently pinch a small section of skin on the forearm or sternal area between the thumb and forefinger and then release the skin ( Fig. 9.11 ). The skin should move easily when pinched and return to place immediately when released. Poor skin turgor can indicate severe dehydration. The skin is very slow to return to normal and “tents” up. This may occur with excessive vomiting, diarrhea, or dehydration for another cause. Skin that is firm or cannot be pinched may suggest an underlying connective tissue disease such as scleroderma.
Skin Lesions
As you assess the skin, pay particular attention to any lesions that may be present. “Skin lesion” is a general term that collectively describes any pathologic skin change or occurrence. Lesions may be primary (i.e., those that occur as initial spontaneous manifestations of a pathologic process) or secondary (i.e., those that result from later evolution of or external trauma to a primary lesion).
Tables 9.4 and 9.5 show the characteristics of primary and secondary lesions. The nomenclature is often used inaccurately; if you are uncertain about a lesion, use the descriptors rather than the name. Be aware that several types of lesions may occur concurrently and that secondary changes may obscure primary characteristics.
Describe lesions according to characteristics ( Table 9.6 ), exudates, configuration, and location and distribution:
| CHARACTERISTIC | DESCRIPTION | EXAMPLES |
|---|---|---|
| Distribution | ||
| Localized | Lesion appears in one small area | Impetigo, herpes simplex (e.g., labialis), tinea corporis (ringworm) |
| Regional | Lesions involve a specific region of the body | Acne vulgaris (pilosebaceous gland distribution), herpes zoster (nerve dermatomal distribution), psoriasis (flexural surfaces and skin folds) |
| Generalized | Lesions appear widely distributed or in numerous areas simultaneously | Urticaria, disseminated drug eruptions |
| Shape/Arrangement | ||
| Round/discoid | Coin-shaped (no central clearing) | Nummular eczema |
| Oval | Ovoid shape | Pityriasis rosea |
| Annular | Round, active margins with central clearing | Tinea corporis, sarcoidosis |
| Zosteriform (dermatomal) | Following a nerve or segment of the body | Herpes zoster |
| Polycyclic | Interlocking or coalesced circles (formed by enlargement of annular lesions) | Psoriasis, urticaria |
| Linear | In a line | Contact dermatitis, poison ivy |
| Iris/target lesion | Pink macules with purple central papules | Erythema multiforme |
| Stellate | Star-shaped | Meningococcal septicemia |
| Serpiginous | Snakelike or wavy line track | Cutanea larva migrans |
| Reticulate | Netlike or lacy | Polyarteritis nodosa, lichen planus, lesions of erythema infectiosum |
| Morbilliform | Measles-like: maculopapular lesions that become confluent on the face and body | Measles, roseola, drug eruptions |
| Border/Margin | ||
| Discrete | Well demarcated or defined, able to draw a line around it with confidence | Psoriasis |
| Indistinct | Poorly defined, have borders that merge into normal skin or outlying ill-defined papules | Nummular eczema |
| Active | Margin of lesion shows greater activity than center | Tinea capitus |
| Irregular | Nonsmooth or notched margin | Malignant melanoma |
| Border raised above | Center of lesion depressed compared with the edge | Basal cell carcinoma center |
| Advancing | Expanding at margins | Cellulitis |
| Associated Changes Within Lesions | ||
| Central clearing | An erythematous border surrounds lighter skin | Tinea eruptions |
| Desquamation | Peeling or sloughing of skin | Rash of toxic shock syndrome |
| Keratotic | Hypertrophic stratum corneum | Calluses, warts |
| Punctation | Central umbilication or dimpling | Basal cell carcinoma, molluscum contagiosum |
| Telangiectasias | Dilated blood vessels within lesion blanch completely, may be markers of systemic disease | Basal cell carcinoma, actinic keratosis |
| Pigmentation | ||
| Flesh | Same tone as the surrounding skin | Neurofibroma, some nevi |
| Pink | Light red undertones | Eczema, pityriasis rosea |
| Erythematous | Dark pink to red | Tinea eruptions, psoriasis |
| Salmon | Orange-pink | Psoriasis |
| Tan-brown | Light to dark brown | Most nevi, pityriasis versicolor |
| Black | Black or blue-black | Malignant melanoma |
| Pearly | Shiny white, almost iridescent | Basal cell carcinoma |
| Purple | Dark red-blue-violet | Purpura, Kaposi sarcoma |
| Violaceous | Light violet | Erysipelas |
| Yellow | Waxy | Lipoma |
| White | Absent of color | Lichen planus |
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