Periodic syndromes of childhood.

Periodic syndromes of childhood comprise a large group of disorders that require long-term follow-up to be diagnosed. Several disorders have fixed rhythmicity and are therefore identified more easily. Other disorders are usually diagnosed after a prolonged follow-up and exclusion of other more common childhood diseases. In general, most of the periodic fever syndromes have a benign prognosis, and their symptomatology tends to improve in the long term. Periodic syndromes without fever or chronic pain syndromes constitute not only a diagnostic dilemma but also a therapeutic challenge. A general diagnostic approach to the periodic syndromes is outlined in Figure 1.