[Methotrexate-induced cutaneous reactions: two case reports]

Methotrexate has been prescribed for many years in the treatment of dermatological diseases. Cutaneous side effects of methotrexate are rare and consist chiefly of direct toxicity resulting from overdose. We report herein two original cases of methotrexate-induced cutaneous adverse reactions.

Case 1: A 70-year-old man was followed for bullous pemphigoid. After two relapses with clobetasol, methotrexate was initiated. One month later, a vesicular and itching rash localized on the face and trunk was observed. The lesions systematically occurred in the week following drug-intake and finally healed after dosage reduction. Case 2: An 81-year-old woman was hospitalized for bullous pemphigoid, first treated by clobetasol. She relapsed 5 months later, and methotrexate was initiated subcutaneously. After the third injection, an edematous and papular eruption was observed on the patient's face. The eruption recurred systematically after drug injection and healed after dosage reduction.

The chronology of drug-intake, a positive test following renewed intake and improvement of lesions with a lower dose of methotrexate allowed us to conclude on cutaneous adverse reactions to methotrexate. These two original cases underline the atypical clinical presentation of cutaneous adverse reaction. This diagnosis should be systematically discussed in cases of recurrent rash.