[Enthesitis in the context of spondyloarthritides]

Enthesitis is a frequent manifestation in spondyloarthritis (SpA) and psoriatic arthritis (PsA) and can be found in up to 40 % of patients with SpA. Because of the pathognomonic relevance the classification criteria for SpA and PsA use enthesitis as an entrance or secondary criterion. Enthesitis is most frequently localized at the heel but it can occur at any insertion of an enthesis into the bone. When diagnosing enthesitis differential diagnoses should be considered, mechanical-degenerative causes and fibromyalgia in particular should be excluded. The imaging techniques power Doppler ultrasound (PDUS) and magnetic resonance imaging (MRI) are most helpful in making the diagnosis. The therapeutic options for enthesitis are limited. Nonsteroidal antirheumatic drugs (NSARD) and local injections of corticosteroids are recommended. In small clinical trials no efficacy of disease modifying antirheumatic drugs (DMARD) could be demonstrated. In contrast, tumor necrosis factor alpha (TNF-alpha) blockers were shown to be highly effective in randomized controlled trials for SpA and PsA but they are not currently approved for enthesitis only.