A biopsy was performed and sent for immunofluorescence; the results were negative. This, along with the patient’s history of diabetes, led us to the diagnosis of bullosis diabeticorum (BD). This condition, also known as bullous disease of diabetes, is characterized by abrupt development of noninflammatory bullae on acral areas in patients with diabetes.
The etiology of BD is unknown. The acral location suggests that trauma may be a contributing factor. Although electron microscopy has suggested an abnormality in anchoring fibrils, this cellular change does not fully explain the development of multiple blisters at varying sites.
A diagnosis of BD can be made when biopsy with immunofluorescence excludes other histologically similar diagnoses such as epidermolysis bullosa, noninflammatory bullous pemphigoid, and porphyria cutanea tarda. And, while immunofluorescence findings are typically negative, elevated levels of immunoglobulin M and C3 have, on occasion, been reported.1,2 Cultures are warranted only if a secondary infection is suspected.
The distribution of lesions and the presence—or absence—of systemic symptoms go a long way toward narrowing the differential of blistering diseases. The presence of generalized blistering and systemic symptoms would suggest conditions related to medication exposure, such as Stevens-Johnson syndrome or toxic epidermal necrolysis; infectious etiologies (eg, staphylococcal scalded skin syndrome); autoimmune causes; or underlying malignancy.3 Generalized blistering in the absence of systemic symptoms would support diagnoses such as bullous impetigo and pemphigoid.3
The blisters associated with BD spontaneously resolve over several weeks without treatment but tend to recur. The lesions typically heal without significant scarring, although they may have a darker pigmentation after the first occurrence. Treatment may be warranted if a patient develops a secondary infection. For this patient, the bullae resolved within 2 weeks without treatment, although mild hyperpigmentation remained.
This case was adapted from: Mims L, Savage A, Chessman A. Blisters on an elderly woman’s toes. J Fam Pract. 2014;63:273-274.