Efficacy and safety of sulfasalazine in patients with chronic idiopathic urticaria

Background: There are limited data regarding alternative treatments for antihistamine refractory chronic idiopathic urticaria (CIU). Patients with recalcitrant skin disease often cannot gain satisfactory symptom control with standard therapies and may require prolonged courses of oral corticosteroids. There is a lack of information describing the degree and duration of sulfasalazine's efficacy, the frequency and nature of adverse reactions, and the appropriate safety monitoring parameters.

Objective: To present a case series detailing the efficacy and safety of sulfasalazine therapy in patients with CIU.

Methods: A retrospective chart review was conducted of 39 patients with sulfasalazine-treated CIU evaluated at Johns Hopkins Asthma and Allergy Center from October 2007 to March 2012. Eight patients were excluded from the final analysis.

Results: Twenty-six patients (83.9%) showed an improvement in symptoms within the first 3 months, with 51.6% of patients (n = 16) becoming asymptomatic within the first 6 months of starting sulfasalazine. Eleven patients (35.4%) achieved complete relief of symptoms after tapering off sulfasalazine therapy. Five of the 31 patients (16.1%) failed treatment, defined as worsening symptoms and pursuit of an alternative therapy. Six of 31 patients (19.4%) had a modified course of sulfasalazine therapy owing to abnormal hematologic parameters. Serious adverse events leading to drug discontinuation occurred in 6.5% of patients (n = 2) and included a patient with drug-induced leukopenia and one with rhabdomyolysis.

Conclusion: Sulfasalazine is a highly effective treatment for patients with antihistamine resistant CIU. The frequency of adverse events leading to an alteration of sulfasalazine treatment supports the need for close monitoring of these patients.