Generalized cutaneous Rosai-Dorfman disease presenting as ac
A 48‐year‐old man presented with a 4‐month history of asymptomatic, dome‐shaped, red‐brown, shiny surfaced papules and nodules on his face, limbs and trunk. Imaging, clinical examination and laboratory findings were unremarkable.

Histopathology demonstrated numerous infiltrating histiocyte‐engulfed inflammatory cells, forming ‘emperipolesis’. Immunohistochemically, histiocytes were CD68 and S100 positive, but CD1a negative.

Cutaneous Rosai-Dorfman disease (CRDD) was diagnosed. CRDD is a rare entity, especially presenting as generalized acneiform lesions.

Key takeaways:-
- The shiny surface and absence of pustules may be a useful clinical clue to distinguish CRDD from acne

- The histological and immunohistochemical features play a decisive role in diagnosis.