Abstract

Dowling-Degos disease (DDD) is a rare autosomal dominant dermatosis characterized by acquired reticular hyperpigmentation in the skin folds, with histopathological features including basilar hyperpigmentation and elongation of the rete ridges. Galli-Galli disease (GGD) is a variant of DDD, sharing genetic mutations (KRT5 and POTGLU1), but distinctively exhibits suprabasalilar acantholysis, and can present clinically with inflammatory manifestations such as papules, vesicles, erosions, and crusts. Management of GGD remains challenging due to the lack of established treatment guidelines. We present a case of GGD in an 80-year-old man with a history of seborrheic dermatitis and extensive keratinocyte carcinomas. Initially mimicking Grover’s disease both clinically and histopathologically, our case underscores the diagnostic complexity of GGD, emphasizing subtle histopathologic clues. We provide high-quality clinical and histographic evidence demonstrating exceptional clinicopathologic correlation. Although this case lacks genetic confirmation, the compelling histopathology and clinical presentation aid in rendering the diagnosis. Our presentation aims to offer a concise review of GGD, educating the audience on this rare condition. Given the limited evidence supporting specific treatment options, highlighting the distinctive features and diagnostic challenges of GGD is crucial for enhancing clinical recognition and optimizing management.