Acne keloidalis nuchae (AKN) is a condition characterized by follicular-based papules and pustules that form hypertrophic or keloidlike scars. AKN typically occurs on the occipital scalp and posterior neck and develops almost exclusively in young, African American men. [1] The term acne keloidalis nuchae is somewhat of a misnomer because the lesions do not occur as a result of acne vulgaris, but rather a folliculitis. Moreover, histologically lesions are not keloidal, nor do the affected patients tend to develop keloidalis in other areas. [2]
Acne keloidalis nuchae was first recognized as a discrete entity in the late 1800s. Hebra was the first to describe and document this condition in 1860, under the name sycosis framboesiformis. Subsequently in 1869, Kaposi described this same condition as dermatitis papillaris capillitii. [3] The term acne keloidalis was then given to this condition in 1872 by Bazin, and, since that time, this is the name most often used in the literature. [2]
Lesions initially manifest as mildly pruritic follicular-based papules and pustules on the nape of the neck. Chronic folliculitis ultimately leads to development of keloid-like plaques. AKN develops in hair bearing skin areas, and broken hair shafts, tufted hairs, and ingrown hairs can be identified within and at the margins of the plaques themselves. Lesions can grow over time and become disfiguring and painful. In advanced cases, abscesses and sinus tracts with purulent discharge may develop. Unlike true acne vulgaris, comedones are not a common feature of AKN. [4]
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Numerous acne keloidalis papules and plaques in a white man with straight hair.
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A large acne keloidalis plaque in a bandlike distribution at the posterior occiput in an African American man.
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A large acne keloidalis plaque on the occipital region in an African American patient. This man also had perifolliculitis of the scalp and acne conglobata (the follicular occlusion triad).
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Numerous papules that have coalesced into a large plaque, within which are tufts of hairs with several hair shafts exiting the same follicular orifice.
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A dense plasma cell infiltrate surrounding a hair follicle.
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Naked hair shafts embedded within a fibrotic dermis.
