What is the treatment for physiologic urticaria?

Treatment for Physiologic Urticaria

The first-line treatment for physiologic urticaria is second-generation (non-sedating) H1-antihistamines at standard doses, which can be increased up to four times the standard dose if symptoms remain inadequately controlled after 2-4 weeks. 1, 2

Classification and Types of Physiologic Urticaria

• Physiologic urticarias are triggered reproducibly by specific physical stimuli and include mechanical urticarias (delayed pressure urticaria, symptomatic dermographism, vibratory angio-oedema), thermal urticarias (cholinergic urticaria, cold contact urticaria, localized heat urticaria), and others (aquagenic urticaria, solar urticaria) 3
• These urticarias differ from ordinary urticaria by having identifiable triggers rather than spontaneous occurrence 3
• The duration of individual weals can help distinguish between types: physical urticaria weals typically resolve within an hour (except for delayed pressure urticaria, which can last up to 48 hours) 3

Treatment Algorithm

First-Line Treatment

• Start with standard doses of second-generation H1-antihistamines (cetirizine, desloratadine, fexofenadine, levocetirizine, loratadine) 1, 4
• All patients should be offered the choice of at least two different non-sedating antihistamines as responses vary between individuals 3
• Second-generation antihistamines are preferred over first-generation due to their improved safety profile and less sedating effects 1, 4

Step-Up Approach (If Initial Treatment Is Inadequate)

• If symptoms remain inadequately controlled after 2-4 weeks, increase the dose of second-generation H1-antihistamines up to 4 times the standard dose 2, 4
• Consider adding H2-antihistamines or leukotriene receptor antagonists (montelukast) as adjunctive therapy for resistant cases 1, 5

Second-Line Treatment

• For refractory cases, short courses of oral corticosteroids may be used, but should be avoided for long-term use 1, 6
• For severe antihistamine-resistant cases, consider referral to specialists for additional treatments such as omalizumab (300mg every 4 weeks) or cyclosporine 2, 1

General Measures and Avoidance Strategies

• Identify and minimize exposure to specific physical triggers that induce the urticaria 7
• Avoid nonspecific aggravating factors such as overheating, stress, alcohol, and drugs with potential to worsen urticaria (e.g., aspirin, NSAIDs, codeine) 3
• Apply cooling antipruritic lotions such as calamine or 1% menthol in aqueous cream for symptomatic relief 3
• Consider desensitization to triggers in some physical urticarias 7

Special Considerations

• Distinguish physical urticarias from urticarial vasculitis, which requires different management and has lesions that persist for days 3, 8
• In cholinergic urticaria (induced by sweating), focus on avoiding core temperature increases 3
• For cold urticaria, patients should avoid sudden exposure to cold and swimming alone 7
• For delayed pressure urticaria, minimize prolonged pressure on the skin 7

Monitoring and Follow-up

• Regularly assess disease activity, impact on quality of life, and treatment response 2
• Consider stepping down therapy after achieving complete symptom control for at least 3 consecutive months 2
• When stepping down, reduce the daily dose gradually (no more than 1 tablet per month) 2
• If symptoms recur during step-down, return to the last effective dose that provided complete control 2

Physical urticarias often have excellent prognosis for eventual recovery, though some may be especially persistent 3. Proper identification of triggers and appropriate antihistamine therapy can significantly improve quality of life for most patients.