[Clinical pitfalls in the diagnosis of microcrystalline arthritis].

Diagnosis of microcrystalline arthritis often is based on joint punctures, performed whenever possible. The clinical features of the crises may suggest diagnosis, but is not decisive. The course before or during treatment is not indicative and cannot fully exclude infection when the patient is seen during a crisis; arthritis with one or several microcrystals is possible, as in forms associated with joint infection. For well-oriented management, good knowledge of such diagnostic difficulties is necessary.