Bullosis Diabeticorum: A Rare Presentation with Immunoglobulin G (IgG) Deposition Related Vasculopathy. Case Report and Focused Review

BACKGROUND Bullosis diabeticorum (BD) is a condition characterized by recurrent, spontaneous, and non-inflammatory blistering in patients with poorly controlled diabetes mellitus. While etiopathogenesis remains unclear, roles of neuropathy, vasculopathy and UV light are hypothesized. Most literature reports negative direct and indirect immunofluorescence findings in diabetics with bullous eruptions. Porphyria cutanea tarda, bullous pemphigoid, epidermolysis bullosa, and pseudoporphyria are other differential diagnoses of bullous lesions, and they must be excluded. CASE REPORT We present a 42-year-old African American male with long standing poorly controlled insulin dependent diabetes mellitus with blisters on his left hand and feet. The blisters were noticed three weeks prior to presentation and, thereafter, rapidly increased in size and spontaneously ruptured. Physical examination revealed a multitude of both roofed and unroofed bullous painless skin lesions. Hematoxylin and eosin (H&E) staining dramatized the dermal-epidermal blistering and re-epithelization process. Direct Immunofluorescence (DIF) was positive for 2 + IgG deposition in the already thickened basement membrane of the capillaries of the superficial vascular plexus. After debridement, his wounds greatly improved with over three months of aggressive wound care. CONCLUSIONS Primary immunologic abnormality likely plays no role in the onset of BD. To date, only one article has reported nonspecific capillary-associated immunoglobulin M and C3. This is the first case of BD with IgG deposition in the superficial capillary basement membrane. Positive findings on DIF suggest vasculopathy. Dermal microangiopathy, secondary to immunologic abnormality, is a possible underlying pathogenesis to bullae formation. Punch biopsy with DIF can be an additional diagnostic modality in the management of such cases.