Desloratadine in combination with montelukast suppresses the dermographometer challenge test papule, and is effective in the treatment of delayed pressure urticaria: a randomized, double-blind, placebo-controlled study.

Background: Delayed pressure urticaria (DPU) comes under the heading of physical urticaria. Characteristically itchy, tender or painful weals occur at sites of local pressure including the waistband, soles of the feet and palms of the hands. Lesion onset is typically 3-12 h after the application of pressure, and lesions may persist for more than 24 h. The treatment of DPU is often unsatisfactory.

Objectives: To determine the efficacy of desloratadine and montelukast in the treatment of DPU.

Methods: The study was conducted in 36 subjects affected by DPU. A challenge test with a dermographometer was administered to confirm the diagnosis. After diagnosis, patients were randomized to receive the following treatment once daily for 2 weeks: (i) oral desloratadine 5 mg plus oral placebo; (ii) oral desloratadine 5 mg plus montelukast 10 mg; and (iii) oral placebo alone.

Results: At rechallenge, patients from the treatment groups (desloratadine plus montelukast group and desloratadine alone group) demonstrated a significant reduction in mean diameter of papules after 70 s of pressure compared with the placebo group (P < 0.05). Moreover, patients treated with desloratadine plus montelukast showed a significant reduction in mean diameter of papules at 70 s of pressure compared with those treated with desloratadine alone (P < 0.05). In addition, the combination was effective in improving clinical parameters (erythema, oedema and pruritus, and number of separate urticarial episodes).

Conclusions: This study has demonstrated that both desloratadine alone and desloratadine plus montelukast administered once daily yield improvements with respect to the baseline assessment, regarding the suppression of the dermographometer challenge test papule and clinical improvement of urticaria. However, the combination of desloratadine and montelukast was shown to be more efficacious and may therefore be proposed in patients with DPU, in order to avoid corticosteroid therapy.