What is the treatment for exercise-induced urticaria?

Treatment of Exercise-Induced Urticaria

Start with a second-generation non-sedating H1 antihistamine (cetirizine 10 mg daily or loratadine 10 mg daily), and if symptoms persist after 2-4 weeks, increase the dose up to 4 times the standard dose (e.g., cetirizine 40 mg daily). 1

Critical First Step: Confirm the Diagnosis

Before initiating treatment, you must distinguish exercise-induced urticaria from two potentially life-threatening conditions:

• Exercise-induced anaphylaxis presents with hives that progress to systemic symptoms including angioedema, gastrointestinal symptoms, laryngeal edema, and/or vascular collapse—approximately one-third experience loss of consciousness and two-thirds develop upper respiratory obstruction. 1 This requires immediate epinephrine, not antihistamines. 2

• Exercise-induced urticaria presents with isolated conventional wheals (10-15 mm) triggered only by exercise, with generalized pruritus, flushing, and warmth but no systemic progression, vascular collapse, laryngeal edema, or bronchospasm. 1, 3

• Cholinergic urticaria presents with characteristic punctate wheals (1-3 mm, not 10-15 mm) triggered by core body temperature increase from exercise OR passive warming (hot shower, sauna), and responds well to hydroxyzine. 1, 4, 3

Pharmacologic Treatment Algorithm

First-Line: Non-Sedating H1 Antihistamines

• Offer at least two different second-generation antihistamines to each patient, as individual responses vary significantly between agents. 1 Preferred options include cetirizine 10 mg daily, loratadine 10 mg daily, fexofenadine, desloratadine, or levocetirizine. 1

• If inadequate control after 2-4 weeks at standard dose, escalate to 4 times the standard dose (e.g., cetirizine 40 mg daily or loratadine 40 mg daily). 1

Second-Line: Omalizumab

• For urticaria unresponsive to high-dose antihistamines, add omalizumab 300 mg subcutaneously every 4 weeks. 1

• Allow up to 6 months for response before declaring treatment failure. 1

• If insufficient response at standard dosing, increase to 600 mg every 2 weeks as the maximum recommended dose. 1

Third-Line: Cyclosporine

• For patients failing both high-dose antihistamines and 6 months of omalizumab, add cyclosporine to the antihistamine regimen at up to 5 mg/kg body weight. 1

• Cyclosporine is effective in approximately 65-70% of patients with severe urticaria. 1

• Monitor blood pressure and renal function every 6 weeks due to nephrotoxicity and hypertension risk. 1

Essential Non-Pharmacologic Management

Screen for Food-Dependent Exercise-Induced Anaphylaxis (FDEIA)

• Ask specifically about temporal relationship between food ingestion and exercise within 4-6 hours. 1 Common culprits include wheat and soy. 5

• If FDEIA is suspected, advise patients to avoid exercise for 4-6 hours after consuming culprit foods. 1 These patients can ingest the foods without symptoms if they don't exercise. 5

• Note that provocation can occur with latency periods up to 24 hours after food consumption in rare cases. 5

Identify and Eliminate Aggravating Factors

• Screen for NSAID or aspirin use before exercise—13% of exercise-induced anaphylaxis cases involve NSAID ingestion. 5, 1

• Minimize overheating, environmental heat exposure, stress, and alcohol consumption. 1

Symptomatic Relief

• Cooling antipruritic lotions (calamine or 1% menthol in aqueous cream) can provide symptomatic relief. 1

Critical Safety Measures for Exercise-Induced Anaphylaxis (Not Urticaria)

If your patient has true exercise-induced anaphylaxis rather than isolated urticaria:

• Prophylactic antihistamines are NOT effective in preventing exercise-induced anaphylaxis. 5

• Patients must carry epinephrine autoinjectors and wear Medic Alert identification. 5

• They should exercise with a companion versed in EpiPen use. 5

• Epinephrine 0.3-0.5 mg intramuscularly in the anterolateral thigh is the emergency treatment, repeatable every 5-10 minutes as necessary. 2

Common Pitfalls to Avoid

• Do not confuse exercise-induced urticaria with cholinergic urticaria—the latter has punctate (1-3 mm) wheals and is triggered by passive warming, not just exercise. 4, 3

• Do not use chronic oral corticosteroids for exercise-induced urticaria—restrict to short courses (3-10 days) for severe acute exacerbations only. 4

• Do not assume all exercise-related hives are benign—always assess for progression to systemic symptoms that would indicate anaphylaxis requiring epinephrine. 1