Blisters occur spontaneously and abruptly, usually without known antecedent trauma. Lesions tend to be asymptomatic, although mild discomfort or burning has been described. Blisters heal spontaneously within 2-6 weeks of onset. Bullosis diabeticorum presents as tense blisters arising on nonerythematous skin. Elevated levels may indicate porphyria cutanea tarda.
Levels reportedly are normal in bullosis diabeticorum.
No primary immunologic abnormality exists. Nonspecific capillary-associated immunoglobulin M and C3 has been reported rarely. For routine histologic sections, include the blister and portions of the underlying dermis in the biopsy, and submit it in formalin. For biopsy findings, see Histologic Findings. Lesions of bullosis diabeticorum have a heterogeneous histologic presentation.