Urticaria in Child
Alerts and Notices
SynopsisUrticaria is a skin disorder characterized by wheals (hives), angioedema, or both. It is caused by the release of histamine and other vasoactive substances from mast cells. When swelling is superficial, urticaria presents. When the swelling is deeper, angioedema presents.
Urticaria is categorized as acute (new onset or recurring episodes of up to 6 weeks' duration) or chronic (recurring episodes lasting longer than 6 weeks). Chronic urticaria can be spontaneous or inducible and is estimated to occur in 0.1%-1.8% of children.
The most common cause of acute urticaria in children is viral infection, particularly upper respiratory infections. Other causes include food allergy and drug hypersensitivity. In some cases, the inciting factor is never identified.
Chronic urticaria is less commonly seen in children than in adults. Prognosis is also more favorable in children than in adults, with over 95% resolution after 7 years. Chronic urticaria is subdivided into chronic inducible urticaria and chronic spontaneous urticaria, based on whether definite triggers exist and can be identified. Chronic inducible urticaria is triggered consistently, reproducibly, and exclusively by a specific stimulus. These stimuli further define chronic inducible urticaria subtypes: symptomatic dermographism, cold urticaria, delayed pressure urticaria, solar urticaria, heat urticaria, and vibratory angioedema are physical urticarias, whereas cholinergic urticaria, contact urticaria, aquagenic urticaria, and adrenergic urticaria are not.
Chronic spontaneous urticaria may be exacerbated by triggers such as NSAIDs, alcohol, and stress, but triggers are not definite, as stimuli do not always produce symptoms. While the cause of chronic spontaneous urticaria is unknown, the presence of mast cell–activating autoantibodies in many patients raises the possibility of an autoimmune origin. It is also associated with other autoimmune conditions, including vitiligo and type 1 diabetes mellitus.
Other associated factors:
- Acute urticaria – high population density, allergic disease
- Chronic urticaria – hepatitis B virus, hepatitis C virus, Epstein-Barr virus, mycoplasma, systemic lupus erythematosus, neoplasms (especially lymphoreticular cancers and lymphoproliferative cancers), and oral contraceptive pills (OCPs)
- Chronic induced urticaria – environment (temperature, altitude), allergic disease
- Chronic spontaneous urticaria – gastrointestinal tract infection (Helicobacter pylori, bowel parasites) and inflammation (gastritis, reflux esophagitis, cholangitis), bacterial infection of the nasopharynx, cancer, depression, anxiety, and metabolic syndrome
- Vibratory urticaria – mutation in ADGRE2 (EMR2), which affects mast cell function
L50.9 – Urticaria, unspecified
126485001 – Urticaria
Differential Diagnosis & PitfallsMany serious illnesses present with urticarial lesions and should be considered with every case of urticaria. When in doubt, children should be observed for 2-4 hours to monitor for disease progression.
- Serum sickness / serum sickness-like reaction – Associated with fever, lymphadenopathy, arthralgias (look for refusal to use an extremity), dusky skin lesions, and recent drug (ie, beta-lactam) or sera exposure.
- Urticarial vasculitis – Individual lesions last longer than 24 hours and are associated with pain, purpura, and/or arthralgias or arthritis (look for joint swelling or refusal to use extremities).
- Mastocytosis (urticaria pigmentosa) – Has persistent yellow-brown macules and plaques that urticate with stroking.
- Kawasaki disease – The child appears ill and is febrile.
- Acute hemorrhagic edema of infancy – Large annular purpuric papules and plaques, fever, and edema in an otherwise well infant between the ages of 4 months and 3 years.
- Viral exanthem – Nonspecific viral exanthems tend to be more macular and papular with a diffuse distribution.
- Alpha-gal syndrome – Mammalian meat allergy induced by a tick bite that elicits immunoglobulin E (IgE) antibodies to galactose-alpha-1,3-galactose (alpha-gal), resulting in urticaria, angioedema, and anaphylaxis symptoms 3-6 hours (delayed onset) after ingesting the meat. Implicated tick bites have been noted to be pruritic for 2 or more weeks.
- 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 – Lesions are often excoriated and last longer than 24 hours.
- Contact dermatitis (irritant, allergic) may have an unusual geometric shape correlating to the inciting irritant and often develops blisters.
- Lupus erythematosus – Often with epidermal changes (scaly, atrophic, or ulcerated).
- Herpes zoster – May initially be urticarial, but lesions are painful and evolve into blisters and crusts.
- 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
- Bedbug bite
- Toxocariasis – A common cause of chronic urticaria.
- African trypanosomiasis
- Cryopyrin-associated periodic syndromes – Muckle-Wells syndrome, familial cold autoinflammatory syndrome (familial cold urticaria), and neonatal-onset multisystem inflammatory disease.
- Phospholipase Cg2–associated antibody deficiency – Lifelong cold-induced urticaria with variable antibody deficiency and increased risk for infection, autoimmunity, and granulomatous disease.
Drug Reaction DataBelow is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.
Urticaria in Child