Systemic Disease and Dermatologic Emergencies
Dermatologic emergencies
Stevens-Johnson syndrome/toxic epidermal necrolysis (mucosal involvement, Nikolsky positive, drug trigger), erythroderma, angioedema/anaphylaxis, necrotizing fasciitis, and meningococcemia. Early recognition and supportive care save lives.
Systemic associations
Dermatomyositis and malignancy, acanthosis nigricans and insulin resistance/malignancy, pyoderma gangrenosum and IBD, and Sweet syndrome and hematologic malignancy. Paraneoplastic syndromes appear in exam stems.
Drug eruptions
Morbilliform, DRESS (eosinophilia, organ involvement), AGEP (neutrophilia, pustules), and SJS/TEN. Withdrawal of the culprit drug is central.
Traps
- Missing DRESS because rash is nonspecific; check eosinophils and organ function.
- Confusing AGEP with infection; drug history and neutrophilia help.
- Overlooking internal malignancy in new-onset dermatomyositis.
Rule of thumb
For any severe drug eruption, stop the culprit, assess mucosal/organ involvement, and provide supportive care.
Worked example
A patient on carbamazepine with fever, rash, eosinophilia, and transaminitis: diagnose DRESS; stop the drug and start systemic steroids.