Acne keloidalis nuchae: risk factors and associated disorders - a retrospective study

Acne keloidalis nuchae (AKN) is a chronic scarring folliculitis which usually occurs in young adult males of African descent. Studies have suggested that AKN may be associated with other dermatologic conditions and even general medical disorders. The aim of this study was to identify cutaneous and extracutaneous associated disorders and to examine risk factors in our population for developing AKN.

The study was a retrospective, descriptive, and analytical study conducted at the Dermatology Outpatient department of the University Hospital of the West Indies. Data were obtained from the medical records of patients diagnosed over a 15-year period (2000-2014).

There were 1031 new patients during the study period. Of these, 43 (4.2%) had AKN. The male to female ratio for AKN was approximately 7:1. Pseudofolliculitis barbae was associated with keloidal plaques on the scalp (OR = 6.22, P = 0.036). Also, when the duration of AKN was divided into two groups (0-5 years and greater than 5 years), there was an association between keloidal plaques and duration of greater than 5 years (OR = 7.5, P = 0.032). However, when the odds ratio was adjusted, only the duration of AKN remained significantly associated with keloidal plaques (OR = 7.08, P = 0.047). Chronic scalp folliculitis (P = 0.001) and the presence of any component disease of the metabolic syndrome (OR = 14, P = 0.008) and specifically hypertension (OR = 6.75, P = 0.036) were significantly associated with the extension of the lesions beyond the nape and occipital scalp.

Pseudofolliculitis barbae, chronic scalp folliculitis, and aspects of the metabolic syndrome may be associated with acne keloidalis nuchae.