Differential diagnosis of acute dactylitis psoriatica.

A bulbous or "sausage-shaped" finger may represent a special type of psoriatic arthritis without any rheumatoid factor activity. Dactylitis psoriatica must be suspected in cases of arthralgias progressing along the phalanges of a finger associated with global soft tissue swelling. Acute dactylitis psoriatica is characterized by an intermittent course combined with psoriatic and partly extremely mild or masked skin and nail changes. X-rays findings are spicular protuberances at diaphyses in a "cloudy collar" image. Symptomatic treatment of dactylitis psoriatica consists of non-steroidal antirheumatic drugs or basic gold salt therapy. In the interval additional surgical treatment using arthro-plasties and arthrodeses is indicated in cases of joint destruction. Amputation of the affected finger is not to be considered as a mandatory causal therapy of dactylitis psoriatica.