Abstract Introduction Cutaneous ulcerations with violaceous undermined borders are classically associated with pyoderma gangrenosum (PG), a neutrophilic dermatosis often linked to systemic disease. However, infectious mimics must be carefully excluded, particularly in immunocompromised individuals. We present a case of a young woman initially misdiagnosed and treated for PG whose underlying, previously undiagnosed HIV infection led to severe disseminated herpes simplex virus (HSV) dermatitis with central nervous system involvement. Case Report A 30-year-old female without significant past medical history presented with widespread painful ulcerations and violaceous, undermined borders over her extremities, groin, trunk, face and hands. The clinical appearance was consistent with pyoderma gangrenosum, though no inflammatory or autoimmune trigger was identified. Patient required admission to Intensive Care Unit for burn level wound care as well as extensive pain control. She was treated empirically with high-dose corticosteroids and a single infusion of infliximab, with progression of wounds despite therapy.After one month of hospitalization, she was transferred to a tertiary referral center for further evaluation. HIV testing returned positive, revealing a HIV-1 viral load of 248,000 copies/mL and CD4 count of 111 cells/µL. Patient had not been tested for HIV during her initial month of hospitalization and had no prior history of HIV. Punch biopsy of the skin lesions demonstrated viral vesicular dermatitis with necrotic keratinocytes diffusely positive for HSV-1 and weakly positive for HSV-2. These findings prompted revision of her diagnosis from pyoderma gangrenosum to HSV dermatitis. During her admission, she developed altered mental status requiring intubation concerning for HSV encephalitis; lumbar puncture was deferred due to extensive cutaneous involvement of HSV dermatitis. Subsequent ophthalmologic evaluation revealed cytomegalovirus retinitis. Patient was initiated on intravenous acyclovir, intravenous ganciclovir, and highly active antiretroviral therapy (bictegravir, emtricitabine, and tenofovir alafenamide). Patient did not receive further infliximab and was weaned off steroids. Discussion This case underscores the importance of early HIV testing in patients presenting with atypical or treatment-refractory dermatologic conditions. The misdiagnosis of HSV dermatitis as pyoderma gangrenosum led to immunosuppressive therapy, which likely exacerbated viral dissemination and predisposed to further opportunistic infections, including CMV retinitis and superimposed bacterial infection of wounds. Recognition of underlying HIV infection fundamentally altered management—shifting from immunosuppression to antiviral and antiretroviral therapy. Clinicians should maintain a high index of suspicion for infectious etiologies in ulcerative dermatoses, particularly when standard immunosuppression therapy fails to yield improvement. This abstract is funded by: None
Tedeschi et al. (Fri,) studied this question.