An observational analysis of low-dose thalidomide in recalcitrant prurigo nodularis.

Thalidomide has been used as an effective treatment for prurigo nodularis (PN) with a median dose of 200 mg, but the risk of peripheral neuropathy precludes long-term use. We analysed the efficacy of low-dose thalidomide (< 100 mg) in 17 patients with recalcitrant PN. Patients were initiated on thalidomide 50 mg on alternate days, and the dose was increased (doubled) in a stepwise manner, if needed, until a ≥ 50% reduction in score (partial response; PR) on a visual analogue scale (VAS) was achieved. Thalidomide then was continued at the same dose for 4 weeks to achieve ≥ 90% decrease in VAS score; if this was not achieved, the dose was increased to a maximum of 100 mg and continued until complete resolution of lesions (complete response; CR). Four patients discontinued thalidomide due to adverse effects. Four patients achieved PR, while 9 patients (n = 2 with 50 mg, n = 7 with 100 mg) achieved CR. No patient developed neuropathy. In addition, complete responders achieved an earlier ≥ 50% reduction in VAS score. Two patients relapsed after 12 months but responded to thalidomide 50 mg.