Cutaneous drug eruptions associated with the use of biologies and cutaneous drug eruptions mimicking specific skin diseases.

Drug eruptions are common adverse events affecting approximately 3% of hospitalized patients, and can be seen with the use of almost any medication. Making a diagnosis could be challenging because no pattern is specific for a particular drug. A study of clinical aspects, histopathology and history of drug intake is usually necessary to establish the diagnosis, and discontinue the offending agent when feasible. The pathomechanisms of drug-related skin reactions remain unclear. However, the induction of drug reactions by a new class of biologies which block a specific target should help to better understand the pathogenesis of these eruptions.