Delayed pressure urticaria - dapsone heading for first-line therapy?

Background: Pressure urticaria as a subform of physical urticaria is rare and treatment is often difficult. Established therapeutic regimes include antihistamines (generally exceeding approved dosages in order to achieve a therapeutic benefit) or antihistamines combined with montelukast. Complete relief of symptoms is difficult.
Patients and Methods: We used dapsone as an early therapeutic alternative in the event of treatment failure and established a standardized therapeutic regime at our clinic. We surveyed 31 patients retrospectively who had received dapsone between 2003-2009.
Results: In 74 % of patients in whom symptoms persisted despite established therapies, the results of treatment with dapsone were good or very good. Longer-term pressure urticaria and the co-existence of a chronic spontaneous urticaria were associated with a smaller benefit (p<0.05). No significant effects were found related to age, gender, duration of therapy, side-effects, or Met-Hb elevation (a tendency toward a decreased benefit was associated with middle-age, male sex, shorter duration of therapy, observed side-effects, and Met-Hb elevation).
Conclusions: Therapy is well tolerated and results in a good therapeutic benefit which lasts after termination of therapy. With adequate monitoring, the use of dapsone in patients with pressure urticaria has such a good risk-benefit ratio that we support early treatment initiation.
(© The Authors • Journal compilation © Blackwell Verlag GmbH, Berlin.)