Prurigo nodularis: retrospective study of 13 cases managed with methotrexate

Background. Prurigo nodularis (PN), or nodular prurigo, is a chronic, debilitating, inflammatory skin disease. It can be very difficult to manage, and represents a challenge for the physician. Methotrexate (MTX) is a safe folic acid antagonist widely used in the management of inflammatory skin diseases such as psoriasis. Weekly administration of 7.5–20 mg (low-dose methotrexate, LD-MTX) represents an attractive treatment option, and could therefore find a place in the management of PN. Aim. To evaluate the efficacy of LD-MTX as a treatment option for PN. Methods. Thirteen patients who had failed to respond to conventional therapies such as topical steroids, phototherapy and anti-pruritic agents were treated with LDMTX. The mean age of the patients was 75.83. Objective symptoms (Prurigo Nodularis Area and Severity Index; PNASI) and subjective symptoms (Pruritus Numeric Rating Scale; PNRS) were recorded. Treatment consisted of one subcutaneous injection of MTX 7.5–20 mg once weekly for a minimum of 6 months. Adjuvant application of emollients and topical steroids was maintained where needed. Results. Remission or marked improvement (decrease in both PNRS or PNASI of > 75%) was observed in 10 cases, a trend to improvement in 2 cases and relapse in 1 case after treatment discontinuation. Conclusions. LD-MTX may allow improvement of PN in some patients, with longlasting remission.