P Infections (mainly viral upper respiratory tract infections). Acute urticaria may develop during or following a viral or bacterial infection,

What are the most common causes of acute urticaria in paediatrics?

• Idiopathic (often the majority)
• Infections (mainly viral upper respiratory tract infections). Acute urticaria may develop during or following a viral or bacterial infection,
• Food and drugs (allergic and pseudoallergic). Acute urticaria is one of the main manifestations of IgE mediated food allergy, but food allergens are responsible for less than 7% of all cases of urticaria (2). IgE mediated reactions usually present with urticaria within minutes to two hours following exposure to the allergen. Beta-lactams (penicillins and cephalosporins) are the most commonly reported antibiotics, although antibiotics from virtually all classes have been reported. Consider an allergic cause if episodes occur under similar circumstances e.g. following ingestion or exercise. Food dependent exercise-induced anaphylaxis is an IgE-mediated hypersensitivity to food and anaphylaxis which only occurs when both the food is ingested and exercise takes place. (i.e. intake of these foods is tolerated in the absence of exercise which distinguishes it from food allergy). Implicated food products are wheat (most common), cereals, shellfish, nuts, vegetables, fresh fruit, eggs, and milk.
• Stings (e.g. bee, wasps). N.B. Bedbugs, fleas and mites can cause papular urticaria which resolve over weeks.