A rare autoinflammatory syndrome defined as recurrence of pericardial inflammation of unknown origin following the first episode of acute pericarditis and a symptom-free interval of 4-6 weeks or longer. Recurrent attacks of chest pain may be the sole presentation or the chest pain may be accompanied by pericardial friction rub, electrocardiographic or echocardiographic changes, pericardial effusion and increased C-reactive protein. Cardiac tamponade is a rare, life-threatening complication.