Tylenol or acetaminophen: a recurrent fixed drug eruption perpetuated through the use of inconsistent drug terminology.

An 87-year-old man with a history of osteoarthritis presented with worsening knee pain. He was prescribed acetaminophen with codeine. A few days later, he developed a rash on his right buttock and proximal thigh, similar to a rash he experienced in the past when he took over-the-counter (OTC) acetamenophen and an unknown lozenge to treat a presumed viral illness. A fixed drug eruption (FDE) was diagnosed and the patient was asked to avoid Tylenol and other OTC lozenges. Tylenol was entered as an allergy in the electronic medical records. However, since Tylenol, not acetaminophen was listed in the allergy profile, the order for acetaminophen and codeine did not generate an alert for the prescribing physician. Additionally, the dispensing pharmacist did not question the prescribing physician and the patient, unaware that acetaminophen in the pain medication is the same drug as Tylenol, took it and developed recurrent FDE.