Abstract: Methotrexate is first-line drugs in patients with Psoriatic arthritis (PsA). However, the patients differ from treatment sensitivity and tolerance. Here we report a PsA patient with low sensitivity successfully treated with high dose methotrexate. The effective dose is up to 40 mg, once a week. After controlled the condition, TNF-α inhibitor was given additionally. The dose of MTX was gradually reduced to 20mg once a week. We followed 36 weeks and the patient's condition is stable with no joint pain.

Key words: psoriatic arthritis, methotrexate, drug hyposensitivity