Granuloma formation induced by spines of the cactus, Opuntia acanthocarpa.

Embedded cactus spines may cause immediate pain due to mechanical damage, be a source of infection, or result in foreign body granulomas. The cholla cacti are particularly tenacious in the manner in which the spines stay embedded in the skin. Pulling away from the cactus may result in a portion breaking away from the main plant and embedding other spines. Granuloma formation has been seen with plant material embedded in the dermis. Onset is generally within a few days, and duration may be as long as 9 mo. Treatment is generally best accomplished with a topical corticosteroid. We present a case of granuloma caused by the cactus Opuntia acanthocarpa which persisted for 8 w despite topical treatment with 0.05% fluocinonide.