From the Guidelines
For heat-induced hives, the most effective treatment is taking an over-the-counter antihistamine like cetirizine (Zyrtec) 10mg or fexofenadine (Allegra) 180mg once daily, as antihistamines are the mainstay of therapy and show a good response in over 40% of patients 1. When experiencing heat-induced urticaria, it is essential to apply a cool, damp cloth to the affected areas for immediate relief. Additionally, avoiding hot showers, strenuous exercise in heat, and wearing loose, breathable clothing can help alleviate symptoms.
- Key management strategies include:
- Identifying and avoiding triggers
- Staying hydrated
- Using air conditioning when possible
- Applying cool compresses to affected areas For severe cases, consulting a doctor may be necessary, as they may prescribe stronger antihistamines or corticosteroids, such as prednisolone 50 mg daily for 3 days in adults 1. However, long-term oral corticosteroids should not be used in chronic urticaria except in very selected cases under regular specialist supervision 1.
- It is crucial to seek medical attention if hives persist or worsen, as it could indicate a more serious condition. Antihistamines work by blocking histamine, the chemical that causes itching and swelling, while cooling the skin helps constrict blood vessels and reduce inflammation.
From the Research
Treatment Options for Heat-Induced Urticaria
- The treatment of heat-induced urticaria typically involves the use of nonsedating H1 antihistamines, which are effective in nearly 60% of patients, although full symptom relief is achieved in only a minority of them 2.
- A heat desensitization programme can be an effective treatment for heat-induced urticaria 2.
- Omalizumab has proven effective in recent case reports for the treatment of heat-induced urticaria 2.
- Second-generation, relatively non-sedating H₁-receptor blockers are typically employed for the treatment of chronic spontaneous urticaria, which may also be effective for heat-induced urticaria 3.
- First-generation antihistamines, such as hydroxyzine or diphenhydramine, may also be used, but they can cause sedative and anticholinergic side effects 3, 4, 5, 6.
Antihistamine Therapy
- Low-sedating H1 antihistamines, such as terfenadine, astemizole, loratadine, and cetirizine, are considered first-line agents for the treatment of chronic urticaria and may also be effective for heat-induced urticaria 4, 5, 6.
- The choice of a particular low-sedating H1 antihistamine depends on pharmacokinetic considerations and frequency of administration 5.
- Newer nonsedating antihistamines, such as acrivastine, cetirizine, loratadine, mizolastine, fexofenadine, ebastine, azelastine, and epinastine, have reduced adverse effects and cause significantly less sedation and psychomotor impairment than older antihistamines 6.