What is the initial treatment for autoimmune urticaria?

Initial Treatment for Autoimmune Urticaria

Start with second-generation H1 antihistamines at standard doses as first-line therapy, escalate to 4 times the standard dose if inadequate response after 2-4 weeks, then add leukotriene receptor antagonists (particularly beneficial for autoimmune urticaria), and reserve short-course corticosteroids only for severe cases unresponsive to antihistamines. 1, 2

First-Line Treatment: Second-Generation Antihistamines

• Begin with a single second-generation H1 antihistamine (cetirizine, loratadine, fexofenadine, levocetirizine, or desloratadine) at standard dosing for 2-4 weeks 1, 2, 3
• More than 40% of patients respond adequately to antihistamines alone 1, 2
• Cetirizine is preferred due to its shortest time to maximum concentration, providing more rapid symptom relief 2
• Offer at least two different antihistamines during the treatment course, as individual responses and tolerance vary 3

Dose Escalation Strategy

• If standard dosing provides inadequate control after 2-4 weeks, increase the antihistamine dose up to 4 times the standard dose before adding other therapies 1, 2, 3
• This dose escalation corresponds to the maximal doses of first-generation antihistamines used historically 4
• First-generation antihistamines like hydroxyzine may be added at night for additional symptom control and to help with sleep, but are not recommended as first-line monotherapy due to sedation 3, 5

Second-Line Adjunctive Therapies

• Add leukotriene receptor antagonists (montelukast) as adjunctive therapy, which are particularly beneficial for autoimmune urticaria 2, 5
• Remission can be achieved in 20-50% of chronic urticaria patients unresponsive to antihistamines alone when leukotriene antagonists are added 5
• H2-antihistamines (ranitidine or famotidine) can be added for resistant cases, though their utility is limited 2, 4

Role of Corticosteroids in Autoimmune Urticaria

• Use short courses of oral corticosteroids (prednisolone 50 mg daily for 3 days in adults, maximum 3-10 days) only for severe acute urticaria not responding to antihistamines 1, 2, 3
• Corticosteroids should never be used as first-line treatment when antihistamines are sufficient 1
• The most critical error is using chronic corticosteroids for chronic spontaneous urticaria, leading to cumulative toxicity without sustained benefit 1
• If prolonged corticosteroid therapy becomes necessary, use the lowest dose able to control symptoms (no more than 10 mg/day prednisone with weekly reduction of 1 mg) 5, 4

Third-Line Therapies for Severe Refractory Autoimmune Urticaria

• Cyclosporine 4 mg/kg daily for up to 2 months is effective in approximately 65-70% of patients with severe autoimmune urticaria unresponsive to antihistamines 1, 2, 3, 6
• Low-dose cyclosporine (mean dose 2.16 mg/kg initially, tapering to 0.55 mg/kg) can achieve 88% improvement after 5 months with minimal side effects 6
• Monitor blood pressure, urine protein, blood urea nitrogen, and creatinine every 6 weeks during cyclosporine therapy 2, 4
• Treatment duration of 16 weeks is superior to 8 weeks for reducing therapeutic failures 3

Alternative Third-Line Option

• Omalizumab 300 mg subcutaneously every 4 weeks is recommended for chronic spontaneous urticaria unresponsive to high-dose antihistamines, with response rates close to 75% 1, 2, 3, 4
• Allow up to 6 months for patients to respond to omalizumab before considering alternative treatments 3

Critical Pitfalls to Avoid

• Never continue corticosteroids beyond 3-10 days for acute urticaria due to cumulative toxicity 1
• Avoid aspirin and NSAIDs, as they inhibit cyclooxygenase and can exacerbate urticaria symptoms 2, 3
• Avoid ACE inhibitors in patients with angioedema, and use cautiously when angioedema accompanies urticaria 2, 3
• Do not use corticosteroids as first-line treatment; always attempt antihistamine dose escalation first 1

Adjunctive Measures

• Minimize non-specific aggravating factors including overheating, stress, and alcohol 2, 3
• Apply cooling antipruritic lotions (calamine or 1% menthol in aqueous cream) for symptomatic relief 2