Immunologic and Rheumatologic Disorders



Immunologic and Rheumatologic Disorders





Anaphylaxis

Kimberly L. DiMaria

Cheryl N. Bartke


Background



  • Anaphylaxis occurs most commonly among children and adolescents.


  • Although the incidence of allergies and severe allergic reactions is on the rise, the estimated lifetime prevalence of anaphylaxis rate remains low at 0.05% to 2%.


  • Fatal cases of anaphylaxis are rare.



Etiology



  • Most common triggers are food (e.g., eggs, shellfish, nuts), medications (e.g., antibiotics, nonsteroidal anti-inflammatories), and stinging.


  • Can occur through a variety of mechanisms, which are classified into the following categories:



    • Immunologic IgE-mediated/IgE-dependent/type I hypersensitivity reaction.


    • Immunologic non-IgE-mediated/IgE-independent.


    • Nonimmunologic/direct mast cell activation.


    • Idiopathic.


  • An allergen, such as radiocontrast, can precipitate an anaphylactic response through more than one mechanism, either an IgE-mediated response or a direct mast cell activation (i.e., causing histamine release).


  • Regardless of the mechanism, the clinical manifestations and initial management are identical.



Clinical Presentation



  • Rapid onset: minutes to hours.


  • Hives, itching, abdominal pain, emesis, stridor, wheezing, shortness of breath, laryngeal edema, hypotension, and shock.


  • If not treated promptly, can lead to cardiorespiratory collapse and death.


Diagnostic Evaluation



  • Clinical diagnosis based on pathopneumonic symptomology.


  • No specific laboratory test can confirm the diagnosis of anaphylaxis.


  • However, plasma histamine levels, serum total tryptase levels, and serum IgE levels, if measured during or following an anaphylactic episode, are all elevated.



  • Skin testing is indicated to confirm allergens or triggers.



    • Care should be taken to ensure that testing is carried out in a health care facility that can manage anaphylaxis, should the patient develop a reaction to a trigger.


Management



  • ABC assessment.


  • Additional key examination components include pulmonary, neurologic, and skin examinations, and frequent vital signs.


  • Discontinue exposure to trigger/allergen if possible (e.g., a patient receiving intravenous [IV] chemotherapy).


  • Epinephrine administration, intramuscular/subcutaneous; should not be delayed if anaphylaxis is suspected.



    • Delays in administration are associated with worse outcomes.


    • Administration should occur promptly on recognition of mild anaphylaxis symptoms; it is not necessary to wait until potentially life-threatening symptoms develop.


    • 0.01 mg/kg of 1:1,000 (1 mg/mL) into vastus lateralis muscle.



      • Maximum dose: 0.3 mg for children; 0.5 mg for adults.


      • If possible, inject with an autoinjector.


    • Epinephrine is the only effective treatment for anaphylaxis. It will decrease laryngeal edema, treat hypotension and shock, cause bronchodilation, and increase cardiac output by increasing heart rate and myocardial contraction.


    • There is no absolute contraindication of epinephrine administration for treatment of anaphylaxis.


    • Repeat the dose every 5 to 15 minutes as needed.


    • An estimated 20% of patients will require multiple doses of epinephrine.


    • May consider initiating IV epinephrine infusion.


  • Place patient in a recumbent or supine position with lower extremities elevated above the heart.


  • Administer oxygen; secure airway if necessary.


  • Obtain IV access and administer 0.9% normal saline.



    • 30 to 40 mL/kg often required to treat hypotension.


  • Consider administration of adjunctive medications after epinephrine administration.



    • H1-antihistamine: diphenhydramine.


    • Nebulized β-agonist: albuterol.


    • Glucocorticoids: methylprednisolone IV or prednisone PO.


    • H2-antihistamine: ranitidine.



Immunodeficiencies

Megan Trahan



Etiology/Types



  • Humoral.



    • Isolated immunoglobulin deficiency (IgM, IgA, or IgG subclass).


    • X-linked agammaglobulinemia.


    • Common variable immunodeficiency.


    • Transient hypogammaglobulinemia of infancy.


    • Hyper-IgM syndrome.


  • Cellular.



    • 22q11.2 Deletion syndrome.


  • Combined antibody and cellular defects.



    • Severe combined immunodeficiency (SCID).


    • Wiskott-Aldrich syndrome.


    • Ataxia telangiectasia syndrome.


  • Phagocytic.



    • Chronic granulomatous disease (CGD).


    • Hyper-IgE syndrome.


    • Leukocyte adhesion deficits.


  • Complement.



    • Early complement defect (C2, C3, or C5).


    • Late complement defect.



Clinical Presentation



  • Common warning signs of primary immunodeficiency (Table 17.1).


  • In addition to infection, it may present with autoimmune diseases or lymphoid malignancy.


  • Evaluate for syndromes associated with primary immunodeficiency (e.g., 22q11 deletion [DiGeorge syndrome] or ataxia telangiectasia).









    TABLE 17.1 Warning Signs of Primary Immunodeficiency






















    10 Warning Signs of Primary Immunodeficiency


    ≥4 new ear infections within 1 y


    Recurrent, deep skin or organ abscesses.


    ≥2 sinus infections within 1 y


    Persistent thrush in mouth or fungal infection on skin.


    ≥2 mo on antibiotics with little effect


    Need for IV antibiotics to clear infections.


    ≥2 pneumonias within 1 y


    ≥2 deep-seated infections including septicemia.


    Failure of an infant to gain weight or grow normally


    A family history of primary immunodeficiency.


    Adapted from Jeffery Modell Foundation. (2013). 10 warning signs of primary immunodeficiency. Retrieved from www.info4pi.org/aboutPI/index.cfm?section=aboutPI&content=warningsigns



  • Evaluate immune organs: tonsils, spleen, and lymph nodes.


  • Specific disease types and common presentations.



    • Humoral: sinopulmonary infections with encapsulated organisms.


    • Combined (SCIDs): failure to thrive, respiratory tract or gastrointestinal infections, candidal skin infections, Pneumocystis jiroveci pneumonia.


    • Phagocytic (CGD): infection with catalase-positive organisms (Escherichia coli, Pseudomonas, Klebsiella, Serratia, Salmonella, Candida, and Aspergillus).


    • Complement.



      • Early complement defects: sepsis.


      • Late complement defects: Neisseria infections.


Diagnostic Evaluation



  • Complete blood count (CBC): evaluate for anemia, thrombocytopenia, lymphopenia, or neutropenia.


  • Quantitative immunoglobulins (IgG, IgA, IgM, IgE).


  • Total protein and albumin.



    • Low total protein with normal albumin suggests immunoglobulin deficiency.


  • Antibody titers to vaccinations.


  • Complement activity (CH50, C3, and C4).


  • Nitroblue tetrazolium dye test: evaluate for CGD.


Management



  • Depends on specific immunodeficiency.


  • Treat infection with appropriate antimicrobial based on suspected or confirmed organism.


  • Administer leukocyte-poor Cytomegalovirus (CMV)-negative blood when blood product administration is necessary.


  • Consider postexposure prophylaxis for varicella zoster.


  • Avoid live virus vaccines.



Juvenile Idiopathic Arthritis

Jan A. Odiaga


Background



  • Juvenile idiopathic arthritis (JIA) encompasses a complex group of disorders comprising several clinical entities with the common feature of arthritis.


  • Each subtype of JIA is characterized by a different mode of presentation, disease course, and outcome.



Etiology/Types


Jan 30, 2021 | Posted by in NURSING | Comments Off on Immunologic and Rheumatologic Disorders
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