Immunosuppressive drugs are often essential for managing serious diseases such as psoriatic arthritis.
They suppress the immune and inflammatory reaction pathways throughout the body, including those in the skin.
This man who had psoriatic arthritis ceased his methotrexate prior to having shoulder surgery, but upon doing so various areas of his skin erupted with a red scaly rash. Initially this was thought to be psoriasis.
However, this rash with peripheral scale, coupled with a groin rash, nail dystrophy and a red scaly rash on the face,