An unusual adverse drug reaction?

Adult Still Disease (ASD) is a rare (incidence 1-1,6/1,000,000 in Europe) seronegative polyarthropathy diagnosed with clinical criteria, excluding other etiologies. Minocycline, a semisynthetic derivative of tetracycline, has been associated with many adverse effects. We present the case of a 18-years-old man with a high suspicion of an adverse drug reaction (ADR), that was finally diagnosed of ASD. In order to exclude other diseases, laboratory test, radiology and allergological studies were performed. The results of the allergological studies excluded the possibility of an ADR. The rest of the results determined the diagnosis of ASD. It's necessary to emphasize the importance of an accurate differential diagnosis in cases like this, because many diseases may mimic an ADR, and may be underdiagnosed (or misdiagnosed).