Chronic spontaneous urticaria — SCE Dermatology MCQ

Correct answer: B — Increase the second-generation H1 antihistamine dose

The correct answer is B, increase the second-generation H1 antihistamine dose. This woman has classic chronic spontaneous urticaria (CSU): daily migratory wheals for over six weeks, each lesion resolving within 8 hours, and no clinical features suggesting angio-oedema, vasculitis or systemic disease. UK guidance places standard-dose second-generation antihistamines as first-line treatment, and when response is only partial, as with her cetirizine 10 mg daily, the next recommended step is up-titrating the licensed dose, commonly up to fourfold, before considering second or third-line therapies. This approach is safe, evidence-based and must be given an adequate trial because a substantial proportion of CSU patients achieve control at higher antihistamine doses without needing immunosuppression. Why the other options are wrong: A. Oral prednisolone course: Systemic corticosteroids are reserved for short severe flares only, not for a 3-month routine course, given the risks of long-term steroid toxicity and lack of disease-modifying benefit in CSU. E. Ciclosporin before antihistamine optimisation: Ciclosporin is a later-line agent used after failure of up-dosed antihistamines and omalizumab, so starting it before optimising antihistamine dosing skips the required stepwise algorithm and exposes the patient to unnecessary immunosuppressive risk. C. Urgent lesional biopsy for vasculitis: Biopsy is indicated for fixed lesions lasting over 24 hours, painful or bruising wheals, or systemic symptoms, none of which are present here since her wheals are classically migratory and fade within 8 hours. D. Topical clobetasol to wheals: Topical potent steroids have no established role in CSU, which is a mast-cell mediated, mediator-driven condition unresponsive to localised topical treatment. Key point: In CSU with inadequate response to standard-dose second-generation antihistamine, up-dose up to fourfold before considering second-line agents such as omalizumab or third-line ciclosporin.

Reference: BAD Guideline for the Management of People with Chronic Urticaria (2025), recommendation on up-dosing second-generation H1-antihistamines up to fourfold the licensed dose, British Association of Dermatologists, www.bad.org.uk