Allergic to Exercise: A Case of Exercise-Induced Urticaria and Angioedema

A 23-year-old female presented with urticaria, peri-orbital angioedema, wheeze and cough during intense exercise, with progression slowed by exercise cessation. Additional triggers included passive heating and strong emotion, while low-to-moderate intensity exercise did not provoke symptoms. Symptoms occurred independently of food intake. Past medical history included exercise-induced bronchoconstriction (EIB), eczema and seasonal allergies. Skin-prick and specific IgE testing for food allergens were negative, whilst dermatographia testing was positive. Specific IgE testing demonstrated sensitisation to house dust mite and animal dander as well as several moulds. Initial treatment with antihistamines, famotidine and montelukast provided partial symptom control, whilst later addition of omalizumab resulted in resolution of exercise-induced urticaria and angioedema. This case illustrates the diagnostic overlap between exercise-induced anaphylaxis (EIA), a rare, life-threatening syndrome associated with exercise, and cholinergic urticaria, with a possible contribution from symptomatic dermographism and pre-existing symptoms of EIB. This case highlights that exercise-triggered urticarial syndromes may not fit neatly into a single diagnostic category, and that a thorough, trigger-focused history remains a valuable diagnostic tool.