What if skin eruption is not caused by allergic reaction to drugs?

In this case report authors have described a case of a 39 years old Caucasian single man who was unsuccessfully treated for an allergic reaction to drugs by multiple dermatologists, due to two etiologically different diseases. It was a classical second stage syphilitic infection and positive serologic tests for HIV infection, proved by screening and confirmatory tests. Syphilitic infection was treated and followed up by dermatologist and for the treatment of HIV infection, the patient was referred to the Centre for treatment HIV/AIDS in Kosice (Fig. 4, Ref. 3).