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
barrel cactus

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

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.