History: A 50 year-old African American female presents with fever and a painful rash on her extremities. Painful skin lesions appeared 2 weeks ago and had been gradually enlarging and increasing in number. The patient also complained of slight fatigue. She was admitted to the internal medicine service at Barnes Hospital for fever, tachycardia, and rash. She denied any supplements or over the counter medications. The patient had been diagnosed 2 weeks prior to admission with autoimmune encephalitis and treated with prednisone 60 mg per day for the last 2 weeks. She had also visited the emergency department for a urinary tract infection 3 days prior to admission.
PAST MEDICAL HISTORY: Autoimmune encephalitis, chronic obstructive pulmonary disease, hypertension, seizures, and osteoarthritis.
SOCIAL HISTORY: Noncontributory.
FAMILY MEDICAL HISTORY: Breast cancer (3 family members, all in their 4th decade of life)
MEDICATIONS: Keppra, Macrobid, Venlafaxine.
General: Febrile, tachycardic, normotensive, no neurologic deficits.
Upper extremities: Indurated well-demarcated purpuric plaques with minimal epidermal change.
Lower extremities: Indurated well-demarcated purpuric plaques with minimal epidermal change (Figs. 1 and 2).
Digits/nails: No abnormalities noted
Dermpathology: No epidermal change. The dermis showed superficial and deep perivascular lymphocytic infiltrates with rare neutrophils and eosinophils (Fig.4). Vasculitis was not present. Significant deep dermal and focally intraseptal sub-panniculitic inflammatory infiltrates composed of numerous neutrophils and scattered histiocytes (Fig.5). Minimal septal thickening was present. AFB, Fite, GMS, and Gram stains were all negative for microorganisms. Iron stain was also negative.
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