Persistent joint pain in a rare case of plant thorn synovitis

A patient's green fingers turn out to be an uncommon cause of her pain

Lara, aged 60, is generally well, a non-smoker and a keen gardener. She presents with an inflamed, painful right index finger.

barrel cactus

She reports that 10 days earlier while weeding around a barrel cactus, her right index finger was pierced by a spine at the level of the proximal interphalangeal (PIP) joint.

There was no obvious foreign body, and the trivial entry wound swiftly healed.

Today, the skin over the PIP joint is acutely inflamed and painful. There are no systemic signs or symptoms.

A year earlier, Lara’s