Urticaria in Child
A variety of factors, including systemic diseases, infections, drugs, food, insect bites (papular urticaria), and physical agents, may cause urticaria. In children, viral infections are the most common cause of acute urticaria. Less common causes include food and drugs (especially the penicillins). Chronic urticaria is usually idiopathic.
Tick bites from some Amblyomma and Ixodes (and possibly Haemaphysalis) species have been associated with the subsequent development of allergies to mammalian meat (eg, beef, pork) in a small number of patients. It is thought that the allergy is mediated by induced IgE antibodies to alpha-gal (galactose-alpha-1,3-galactose), a mammalian oligosaccharide. Individuals with elevated IgE titers to alpha-gal have experienced urticaria, angioedema, and anaphylaxis symptoms either immediately or 3-6 hours (delayed onset) after ingesting mammalian meat (alpha-gal syndrome). Exactly how the tick bite leads to development of this allergy is unclear. Implicated tick bites have been noted to itch for 2 or more weeks. A blood test for these IgE antibodies exists.
Vibratory urticaria (see physical urticaria) has been associated with a mutation in ADGRE2 (EMR2), which affects mast cell function.
Related topics: Contact urticaria, Cholinergic urticaria, Dermographism, Cold urticaria, Solar urticaria, Pressure urticaria, Urticaria pigmentosa
L50.9 – Urticaria, unspecified
126485001 – Urticaria
Diseases with urticarial lesions include:
- Anaphylaxis – Associated with angioedema and multiple systemic symptoms (especially respiratory and gastrointestinal) that usually begin within minutes of exposure.
- Serum sickness / serum sickness-like reaction – Associated with fever, lymphadenopathy, arthralgias (refusal to use an extremity), dusky skin lesions, and recent drug (ie, beta-lactam) or sera exposure.
- Kawasaki disease – The child appears ill and is febrile.
- Urticarial vasculitis – Individual lesions last longer than 24 hours and are associated with purpura and arthralgias or arthritis (joint swelling or refusal to use extremities).
- Mastocytosis (urticaria pigmentosa) – Has persistent yellow-brown macules and plaques that urticate with stroking.
- Henoch-Schönlein purpura – Associated with fever, edema, palpable purpura, and renal, gastrointestinal, musculoskeletal, and central nervous system disease.
- Angioedema – Edema of the subcutaneous or submucosal tissues rather than edema of the dermis with urticaria, it is not pruritic and commonly affects the face (eyelids, earlobes, lips); familial angioedema usually does not have individual small hives.
- Erythema multiforme – Fixed for several days, does not respond to antihistamines, and associated with dusky, necrotic centers (rather than the pale edematous center of urticaria).
- Papular urticaria / insect bites – Often excoriated and lasts longer than 24 hours.
- Lupus erythematosus – Often with epidermal changes (scaly, atrophic, or ulcerated).
- Herpes zoster – May also be urticarial, but lesions are painful and long lasting.
- Erythema annulare centrifugum – Often with epidermal changes (scale), and lesions persist for weeks.
- Fixed drug eruption
- Exanthematous drug eruption
- Lyme disease
- Erythema marginatum
- Juvenile idiopathic arthritis