Pseudoxanthoma-like papillary dermal elastolysis: A case report (Preprint)

UNSTRUCTURED An 88-year old female presented with axillary lesions on both sides that have developed over a year. She has been asymptomatic, but it was causing cosmetic concerns. There was no significant medical history and she was not taking any medications. Physical exam showed 1-6mm firm yellow dermal papules scattered over the axillae. Initial differential diagnoses included Fox-Fordyce disease and sebaceous cysts. First skin biopsy showed perivascular lymphocytes, extravasated red cells, and skin atrophy thought to be within the normal range expected of an elderly patient. There was some loss of elastic fibres within papillary dermis on Verhoeff-Van Gieson stain, but no clear diagnosis could be made. A second skin biopsy was performed which showed diminution of collagen fibres in reticular dermis and areas in papillary dermis lacking elastic fibres. Differential diagnoses were revised to include pseudoxanthoma-like papillary dermal elastolysis, but histopathology results were not definitive for the diagnosis. The diagnosis of pseudoxanthoma-like papillary dermal elastolysis was made based on the morphology and location of the lesions, epidemiological factors, and histopathological findings. No treatment was initiated, but the patient was content with knowing the diagnosis and agreed to vigilant monitoring of the lesions. This case discourages the sole reliance on histopathological evidence and reminds the importance of gathering clinical evidence to support the diagnosis of pseudoxanthoma-like papillary dermal elastolysis.