Rescue therapy in methotrexate toxicity: case report

Methotrexate (MTX) is widely used for the treatment of psoriasis. It has an antiproliferative action by inhibiting dihydrofolate reductase enzyme, therefore interferes with folic acid synthesis. MTX toxicity is rarely reported and the most common cause of it is accidental overdosage by the patient. This is a case report of a 51-year-old male, a known case of psoriasis, who presented with multiple erythematous tender plaques associated with burning sensation. He self-medicated with tablet MTX 5 mg daily for 10 days when the lesions got exacerbated and was found to be leucopenic. On skin biopsy, diagnosis of psoriasis with MTX induced epidermal necrolysis was established. Patient was treated with filgrastim 300 μg which was given subcutaneously 1 day apart. On follow up, lesions subsided and repeat counts were within normal limits. Patients should be explained about the selected treatment regime and discouraged from self-medicating.