Rashes and skin lesions

CHAPTER 25 Rashes and skin lesions


Dermatological problems result from a number of mechanisms, including inflammatory, infectious, immunological, and environmental (traumatic and exposure-induced). At times, the mechanism may be readily identified, such as the infectious bacterial etiology in impetigo. However, some dermatological lesions may be classified in more than one way. Most insect bites, for example, involve both environmental (the bite) and inflammatory (the response) mechanisms. Awareness of the potential mechanism of any skin rash or lesion is most helpful in identifying the risk a person may have for other illnesses. For example, persons with eczema are also frequently at risk for or have other atopic conditions, notably asthma and/or allergies. Thousands of skin disorders have been described, but only a small number accounts for the vast majority of patient visits.


Evaluation of rashes and skin lesions depends on a carefully focused history and physical examination. The provider needs to be familiar with the characteristics of various skin lesions; anatomy, physiology, and pathophysiology of the skin; clinical appearance of the basic lesion; arrangement and distribution of the lesion; and clinicopathological correlations. Common symptoms associated with specific lesions, such as itching or fever, are also important to know. It is necessary to quickly identify life-threatening diseases and those that are highly contagious. Ultimately, competence in dermatological assessment involves recognition through repetition.



Diagnostic reasoning: initial focused physical examination



Initial inspection


Dermatological assessment is similar to the assessment of most other body systems in that it depends on patient history and physical assessment. However, sometimes a brief physical assessment preceding the history can assist in the development of the initial differential diagnosis, followed by a focused history and further physical examination.



Morphological criteria


Examination involves the classification of the lesion based on a number of morphological features (examples are listed in Tables 25-1 and 25-2 and Figures 25-1 and 25-2). Evaluation should be systematic. Generally, morphological features should be analyzed as follows:



image Identify the location of the lesion(s).


image Identify the distribution of the lesions as localized, regional, or generalized.


image Identify whether the lesion is primary (appearing initially) or secondary (resulting from change in a primary lesion).


image Identify the shape of the lesion and any arrangement if numerous lesions are present.


image Describe the margins (borders).


image Describe the pigmentation, including variations.


image Palpate to assess texture and consistency.


image Measure the size of an individual lesion or estimate size if lesions are numerous or widespread.


Table 25-1 Morphological Criteria of Rashes and Skin Lesions









































































































































































































































NATURE OF LESION DESCRIPTION EXAMPLES
Primary Lesions (develop initially in response to change in internal or external environment of skin)
Macule Discrete flat change in color of skin; usually <1.5-cm diameter Freckle, lentigo, purpura
Patch Discrete flat lesion (large macule); usually >1.5-cm diameter Pityriasis rosea, melasma, lentigo
Papule Discrete palpable elevation of skin; <1-cm diameter; origin may be epidermal, dermal, or both Nevi, seborrheic keratosis, dermatofibroma
Nodule Discrete palpable elevation of skin; may evolve from papule; may involve any level of skin from epidermis to subcutis Nevi, basal cell carcinoma, keratoacanthoma
Plaque Slightly raised lesion, typically with flat surface; >1-cm diameter; scaling frequently present Psoriasis, mycosis fungoides
Wheal Transient pink/red swelling of skin; often displaying central clearing; various shapes and sizes; usually pruritic and lasts <24 hr Urticaria
Tumor Large papule or nodule; usually >1-cm diameter Basal cell carcinoma, squamous cell carcinoma, malignant melanoma
Pustule Raised lesion <0.5-cm diameter containing yellow cloudy fluid (usually infected) Folliculitis, acne (closed comedones)
Vesicle Raised lesion <0.5-cm diameter containing clear fluid Herpes simplex, herpes zoster, contact (irritant) dermatitis
Bulla Vesicle >0.5-cm diameter Bullous pemphigoid, contact (irritant) dermatitis, blisters of second-degree sunburn
Cyst Semi-solid lesion; varies in size from several mm to several cm; may become infected Sebaceous cyst
Secondary Lesions (appear as result of changes in primary lesions)
Crust Dried exudate that may have been serous, purulent, or hemorrhagic Impetigo, herpes zoster (late phase)
Scale Thin plates of desquamated stratum corneum that flake off rather easily Xerosis, ichthyosis, psoriasis
Excoriation Shallow hemorrhagic excavation; linear or punctate; results from scratching Contact (irritant) dermatitis
Lichenification Thickening of skin with exaggeration of skin creases; hallmark of chronic eczematous dermatitis Chronic eczema
Erosion Partial break in epidermis Herpes simplex or zoster, pemphigus vulgaris
Fissure Linear crack in epidermis Xerosis, angular cheilitis, severe eczema
Distribution of Lesions
Localized Lesion appears in one small area Impetigo, herpes simplex (e.g., labialis), tinea corporis (“ringworm”)
Regional Lesions involve specific region of body Acne vulgaris (pilosebaceous gland distribution), psoriasis (extensor surfaces and skinfolds)
Generalized Lesions appear widely distributed or in numerous areas simultaneously Urticaria, disseminated drug eruptions
Shape/Arrangement
Round/discoid Coin or ring shaped (no central clearing) Nummular eczema
Oval Ovoid shape Pityriasis rosea
Annular Round, active margins with central clearing Tinea corporis, sarcoidosis
Zosteriform (dermatomal) Following nerve or segment of body Herpes zoster
Polycyclic Interlocking or coalesced circles (formed by enlargement of annular lesions) Psoriasis, urticaria
Linear In a line Contact dermatitis
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 Confluent and salmon colored Rubeola
Border/Margin
Discrete Well demarcated or defined; able to draw a line around it with confidence Psoriasis
Indistinct Poorly defined; having borders that merge into normal skin or outlying ill-defined papules Nummular eczema
Active Margin of lesion shows greater activity than center Tinea species eruptions
Irregular Nonsmooth or notched margin Malignant melanoma
Border raised above center Center of lesion depressed compared to edge Basal cell carcinoma
Advancing Expanding at margins Cellulitis
Associated Changes Within Lesions
Central clearing 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
Telangiectasias Dilated blood vessels within lesion blanch completely; may be markers of systemic disease Basal cell carcinoma, actinic keratosis
Pigmentation
Flesh   Neurofibroma, some nevi
Pink   Eczema, pityriasis rosea
Erythematous   Tinea eruptions, psoriasis
Salmon   Psoriasis
Tan-brown   Most nevi, pityriasis versicolor
Black   Malignant melanoma
Pearly   Basal cell carcinoma
Purple   Purpura, Kaposi sarcoma
Violaceous   Erysipelas
Yellow   Lipoma
White   Lichen planus


Table 25-2 Descriptive Dermatological Terms

image image

image

FIGURE 25-1 Types of skin lesions.


(From Seidel HM, Ball JW, Dains JE, Flynn J, Solomon B, Stewart R: Mosby’s guide to physical examination, ed 7, St Louis, 2011, Elsevier.)


image

FIGURE 25-2 Typical distribution of papulosquamous eruptions in children. A, Atopic dermatitis: usually located on cheeks, creases of elbows, and knees. B, Seborrheic dermatitis: usually located on scalp, behind ears, in thigh creases, and in eyebrows. C, Scabies: usually located on axillae, webs of fingers and toes, and intragluteal area.


(From Berkowitz C: Pediatrics: a primary care approach, ed 2, Philadelphia, 2000, Saunders.)


Examination in a systematic manner, and in part before obtaining the majority of the history, provides greater relevance to the data. Gloves are not necessary unless there are open, draining, or exudative lesions.



Diagnostic reasoning: focused history





Is the rash associated with an immediate life-threatening condition?



Key questions




image Do you have a fever?


image Are you short of breath?


image Do you have difficulty swallowing?


image Is the rash tender and does it involve mucous membranes?




Fever


Fever is common in viral exanthems (rashes), and the accompanying condition is usually not life-threatening. However, fever, irritability, hypotension, and a macular or petechial rash may indicate meningococcemia. Treatment needs to be immediate to be lifesaving.



Allergic reaction


Urticarial allergic reactions may be associated with angioedema (swelling) of the extremities, face, lips, tongue, and/or airway; cough; wheezing; shortness of breath; or heart palpitations. The sooner symptoms occur after the exposure to the allergen, the more severe is the reaction. Treatment needs to be instituted immediately.



Rash with mucosal involvement


Toxic epidermal necrolysis (Stevens-Johnson syndrome) is a tender, morbilliform, erythematous rash accompanied by fever, conjunctivitis, oral ulcers, and diarrhea. Immediate hospitalization is required to treat exfoliation of large areas of skin. The condition is usually drug-induced.





Is the rash acute or chronic (recurrent)?



Key questions



image How long have you had this rash?


image Have you ever had a rash like this before?



Onset


The diagnosis of skin lesions is initially aided by categorizing the lesion as acute versus chronic or recurrent. Acute eruptions, such as urticaria or various fungal rashes (tinea), are classified as such because they have a tendency to be self-limiting or to not recur after effective treatment. Chronic rashes, such as psoriasis or eczema, may persist or be recurrent with exacerbations and remissions. Box 25-1 shows common rashes categorized by duration. Ascertain the duration of the eruption at presentation; however, the initial occurrence of a chronic rash may present acutely. Conversely, an acute eruption not optimally treated may present as a chronic problem.



Box 25-1 Duration of Rash











Acute Chronic
Allergic or contact dermatitis
Candida dermatitis (diaper rash, intertrigo)
Erythema infectiosum (fifth disease)
Erythema multiforme
Fixed drug eruptions
Folliculitis
Herpes simplex virus (HSV)*
Herpes zoster/varicella zoster (HZ)
Impetigo
Infestations (scabies, pediculosis)
Insect bites
Kawasaki disease
Pityriasis rosea
Septicemia (meningococcal)
Scarlet fever
Tinea (corporis, pedis, versicolor)
Urticaria*
Viral exanthems (measles)		 Acne vulgaris
Bullous pemphigus
Eczema
Erythema nodosum
Kaposi sarcoma
Mycosis fungoides
Polyarteritis nodosa
Psoriasis
Rosacea
Seborrheic dermatitis
Systemic lupus erythematosus

* Occasionally recurrent





Where is the rash in its evolution?



Key questions



image What did this look like initially?


image Has the rash changed? If so, how?


image Has it spread? Where?



Initial presentation


Most skin lesions evolve over time, although this varies from minutes with urticaria to weeks or even months with psoriasis or mycosis fungoides.

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Apr 10, 2017 | Posted by in NURSING | Comments Off on Rashes and skin lesions

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