Blistering Skin Lesions or Staphylococcal Bacteremia: What Came First?

Document Type

Conference Proceeding

Publication Date

4-2023

Abstract

Introduction

Bullous pemphigoid is the most common autoimmune blistering disease and is commonly seen in the elderly. It typically presents with pruritus, tense bullae formation, and negative Nikolsky's sign. Here, we present a case of a patient presenting with polymicrobial bacteremia found to be secondary to newly diagnosed bullous pemphigoid.

Case Presentation

A 75-year-old male presented to our hospital with progressive bilateral foot edema for two weeks. This was followed by the development of bilateral hand swelling, accompanied by blistering necrotic lesions. His medical history was significant for extensive smoking, COPD, pulmonary embolism, cervical stenosis, and he was bedridden at baseline after a remote hip fracture. On arrival, vitals were stable. Physical exam revealed multiple tense vesiculobullous lesions to dorsal and ventral surfaces of bilateral hands and feet with several necrotic appearing toes and several denuded areas at sites of previous vesicles/bullae. His labs revealed a white cell count of 13.3 x109/L, with unremarkable serum chemistries. Given the necrotic toes and diffuse vesiculobullous lesions, vascular, rheumatological, and infectious etiologies were considered in the differential. Arterial and venous duplex scans and CT angiogram of the abdomen were unrevealing. Further workup for hepatitis C, cryoglobulins, ANA, RF, and ANCA was also negative. Blood cultures grew methicillin-sensitive Staphylococcus aureus (MSSA). Given the concern for septic emboli from an unknown source, intravenous cefazolin was initiated, and echocardiograms (transthoracic followed by transesophageal) were obtained which did not show any evidence of endocarditis. MRI of bilateral feet ruled out osteomyelitis. Final blood cultures showed MSSA, Staphylococcus capitis, and Staphylococcus lugdunensis. He also endorsed worsening generalized pruritis for the past few days. Given the new clues in history, spreading bullous lesions despite antibiotics, polymicrobial bacteremia, and mild eosinophilia at presentation, a workup for a vesiculobullous dermatological disorder was performed. In consultation with dermatology, a skin biopsy was deferred and serological testing for bullous pemphigoid was pursued. Serum anti-basement membrane zone antibodies were detected using indirect immunofluorescence (IIF; on both human split-skin and monkey esophagus) as well as ELISA (BP180 and BP230 antibody), which all returned strongly positive. A final diagnosis of primary bullous pemphigoid was made and topical clobetasol ointment and continuation of iv cefazolin resulted in the improvement of skin lesions.

Discussion

In our patient, bullous pemphigoid was diagnosed based on a compatible clinical picture and supporting antibody testing. His advanced age and bedridden condition put him at an increased risk of bullous pemphigoid.1 A tissue specimen is important for routine histopathological examination and direct immunofluorescence microscopy. In the absent/equivocal tissue diagnosis with continued clinical suspicion, serological testing with IIF and ELISA can aid with diagnosis.2 Topical corticosteroids are the mainstay of initial treatment, other options are systemic steroids and doxycycline. A high titer of BP180 Ab may be associated with a higher risk of relapse. As it is a potentially fatal disease, careful diagnosis and prompt treatment are essential.

Comments

American College of Physicians Internal Medicine Meeting, April 27-29, 2023, San Diego, CA

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