Pustular eruption induced by etanercept in a patient with ankylosing spondylitis: a rare side effect.

Etanercept is a tumor necrosis factor alpha (TNF-a) antagonist with anti-inflammatory effects. It is used in the treatment of dermatologic and rheumatologic diseases such as rheumatoid arthritis, polyarticular juvenile rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis. However, etanercept has various cutaneous and systemic side effects.