Dactilitis

In the medical literature dactylitis is defined as a “inflammation of a finger or toe”. It is a typical manifestation of spondyloarthritides, especially of psoriatic arthritis, although this peculiar inflammation can be produced by other entities, such as inflammatory dactylitis (spondyloarthritis, gout or sarcoidosis), infectious dactylitis (tuberculosis, syphilis or blistering distal dactylitis) or non-inflammatory dactylitis (sickle-cell disease). In spondyloarthritis, dactylitis is the result of a flexor tenosynovitis and secondarily of small joint synovitis. Some clinical trials with tumor necrosis factor (TNF)-blockers have evaluated secondary dactylitis and have generally shown efficiency in the control of this peculiar sign. Gout can produce dactylitis due to urate crystal deposits, while other radiological features are similar to those of spondyloarthritides. Chronic sarcoidosis is another cause of dactylitis secondary to granulomatous invasion of the bone and soft tissues. Infectious forms of dactylitis are typical in pediatric ages and can be due to osteomyelitis, as in the case of tuberculosis and syphilis, or to infection of the soft tissues, as in blistering distal dactylitis. Finally, in sickle cell anemia, inflammation is a result of bone marrow infarction.