- These rashes can occur in a variety of inflammatory and infectious conditions, some of which can be rapidly fatal
- Toxic appearance
- Mucosal lesions
- Severe pain
- Very old or young age
- New medication
- Characterized by diffuse red skin from capillary congestion, mimicking a bad sunburn.
- Positive Nikolsky’s sign
- Negative Nikolsky’s sign
- First, try applying lateral pressure to the skin and see if it sloughs (Nikolsky’s sign)
- Then, to further narrow the differential, consider wither or not the patient is febrile or toxic in appearance
- Patients with an erythematous rash plus fever are also at high risk for having a deadly diagnosis
- Nguyen T and Freedman J. Dermatologic Emergencies: Diagnosing and Managing Life-Threatening Rashes. Emergency Medicine Practice. September 2002 volume 4 no 9.