To start off the Society of Dermatology Physician Assistants 19th Annual Fall Dermatology Conference in Los Angeles, CA, Misha Rosenbach, MD, covered diagnoses that should cause terror when a provider sees them: dermatology emergencies. Dr Rosenbach is associate professor of dermatology and internal medicine and director of inpatient dermatology at the University of Pennsylvania.

First, Dr Rosenbach discussed Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), which are defined as less than 10% dermal detachment vs greater than 30% dermal detachment, respectively. Combination SJS/TEN is between 10% and 30% dermal detachment. SJS/TEN is almost always drug induced. The highest risk drugs are antibacterial sulfonamides, anticonvulsants, oxicam nonsteroidal anti-inflammatory drugs, allopurinol, lamotrigine, and nevirapine. The Nicholsky sign is an important tool to use to discern early SJS from other dermatoses. These lesions are painful rather than itchy, and the “targetoid” lesions have a nonblanching, dark red center with an outer dusky/pink, erythematous area.

Patients who present with SJS/TEN should be immediately placed into an intensive care unit or burn unit. Treatment consensus is not strong, but the therapeutic principles center around reducing additional trauma and using corticosteroids, intravenous immune globulin, cyclosporine, and TNF inhibitors.

Next discussed was DRESS, or drug rash with eosinophilia and systemic symptoms, typically happens a few weeks after drug initiation. Patients typically develop a widespread morbilliform rash with facial edema and erythema. “DRESS has eosinophilia in the name, but patients can also have an atypical lymphocytosis,” said Dr Rosenbach. DRESS can have systemic symptoms, so it is important to address early. Treatment typically includes systemic steroids on a long, slow taper and requires long-term follow-up for delayed reactions.

Acute generalized exanthematous pustulosis (AGEP) occurs within 24 to 48 hours of exposure of a medication and presents as a splotchy rash with nonfolliculocentric pustules. In this disease, the most likely causative medication should be discontinued.

Vascular injury, including vasculitis (inflammation) and vasculopathy (sickness or damaging), presents as palpable purpura. More serious vascular injury in the skin includes retiform purpura, which can have clots forming distally, centrally, or everywhere. Dr Rosenbach shared that 2020 article in Journal of the American Academy of Dermatology by Georgeson et al has a succinct six-step summary of treating retiform purpura. Additionally, cryoglobulinemia can cause cutaneous issues, and is “rheumatoid factor positive, and this comes back faster than checking for cryoglobulins,” he added.  

Dr Rosenbach discussed pyoderma gangrenosum (PG). PG major criteria are rapid progression of a painful ulcer with an irregular, violaceous, underminded border and exclusion of other cutaneous ulceration, and minor criteria are pathergy, cribriform scarring, systemic disease associated with PG, histopathologic finding, and treatment response (ie, stop inflammation). “No one should be afraid to do a biopsy [in PG],” said Dr Rosenbach.

The last derm emergency shared was rapidly progressive dermatomyositis (MDA5). MDA5 gets ulcerations because there is vascular injury, explained Dr Rosenbach. These patients have severe interstitial lung disease that needs to be immediately treated with aggressive immunosuppressive treatment.

Reference
Rosenbach M. Diagnoses of terror. Presented at: Society of Dermatology Physician Assistants 19th Annual Fall Dermatology Conference; November 4-7, 2021; Los Angeles, CA.