Munro's microabscess is an abscess (collection of neutrophils) in the stratum corneum of the epidermis due to the infiltration of neutrophils from papillary dermis into the epidermal stratum corneum.

They are a cardinal sign of psoriasis[1] where they are seen in the hyperkeratotic and parakeratotic areas of the stratum corneum.

[2] Munro microabscesses are not seen in seborrheic dermatitis, pityriasis rosea, lichen ruber planus nor dermatitis herpetiformis.

[3] It is named for William John Munro (1863–1908).

This cutaneous condition article is a stub.