Dowling-Degos disease (reticulate pigmented anomaly of the flexures): A clinical and histopathologic study of 6 cases

Background: Few case series describing Dowling-Degos disease (DDD) have bee n reported. Objective: Our purpose was to review the clinical and histopathologic findi ngs in DDD. Methods: We reviewed the clinical and histopathologic findings in 6 patient s with DDD who were evaluated at the Mayo Clinic. Results: In addition to the typical flexural pigmented reticulate macules, comedo-like lesions on the back or neck or both were present in all 6 patie nts; 3 patients had pitted peri oral scars, and 3 patients reported pruritu s of affected flexural areas. Five patients were female, 5 patients had ons et of pigmentation before age 24 years, and 3 patients had a family history of DDD. One patient had additional pigmentation involving the dorsum of th e hands and proximal nailfolds and fingernail dystrophy. Histopathologicall y, pigmented rete ridge elongation with thinning of suprapapillary epitheli um, dermal melanosis, and perivascular lymphohistiocytic infiltration were consistently observed. Conclusion: Comedo-like lesions, pruritus, and pitted perioral scars are co mmon features in association with the reticulate flexural pigmentation. His topathologically, pigmented rete ridge elongation and dermal melanosis of b iopsy specimens from flexural areas are seen.