Race for the Case answers

Diagnose this new case by Marita Yaghi, MD, Uros Rakita, MD, and Stanley Skopit, DO, MSE, FAOCD, FAAD

A 54-year-old incarcerated male was referred to our clinic one month after discharge from an outside hospital for evaluation of a pruritic, painful, desquamating rash of one year’s duration.

At the time of initial admission, he presented with erythroderma, fever, chills, and skin pain. He was treated with systemic corticosteroids and antibiotics without improvement, and his home medications (amlodipine and losartan) were discontinued. Laboratory studies demonstrated leukocytosis (15.7 × 10³/µL) with eosinophilia (14.6%) and a mild elevation in creatinine that resolved with intravenous fluids. A skin biopsy was non-diagnostic, and direct immunofluorescence (DIF) was negative. He was discharged on an 80-mg daily prednisone taper.

At presentation to our clinic, physical examination revealed widespread eroded erythematous plaques with thick scale and crust involving greater than 90% of the body surface area. Eyelid crusting was noted, with no mucosal involvement. The patient endorsed skin soreness, impaired thermoregulation, and eye dryness.

Repeat biopsies from two sites using a 4-mm punch demonstrated intraepidermal acantholysis on hematoxylin and eosin staining and intercellular deposition of IgG and C3 on direct immunofluorescence.

1. Based on the clinical, histopathologic, and laboratory findings, what is the most likely diagnosis?

Answer: Pemphigus vulgaris

2. What are the most likely target antigens involved in this condition?

Answer: Desmoglein 1 and desmoglein 3

3. What therapies can be initiated in addition to systemic corticosteroids in the acute setting?

Answer: Rituximab (FDA approved) or plasmapheresis - also IVIG

4. What potential complications may occur if this condition remains untreated?

Answer: Infections and dehydration leading to death (2-5 year mortality from onset prior to CS in medicine)

5. What is the most common culprit drug in drug-induced forms of this disease?

Answer: Penicillamine for drug-induced pemphigus

6. If his condition were determined to be a paraneoplastic phenomenon, what additional serum antibodies may be present?

Answer: Anti-envoplakin (also periplakin is ok) for paraneoplastic pemphigus