Acne keloidalis nuchae (AKN) is a chronic inflammatory disorder most commonly involving the occipital scalp and posterior neck characterized by the development of keloidlike papules, pustules, and plaques. If left untreated, this condition may progress to scarring alopecia. It primarily affects males of African descent, but it also may occur in females and in other ethnic groups. Although the exact underlying pathogenesis is unclear, close haircuts and chronic mechanical irritation to the posterior neck and scalp are known inciting factors. For this reason, AKN disproportionately affects active-duty military servicemembers who are held to strict grooming standards. The US Military maintains these grooming standards to ensure uniformity, self-discipline, and serviceability in operational settings.1 Regulations dictate short tapered hair, particularly on the back of the neck, which can require weekly to biweekly haircuts to maintain.1-5
First-line treatment of AKN is prevention by avoiding short haircuts and other forms of mechanical irritation.1,6,7 However, there are considerable barriers to this strategy within the military due to uniform regulations as well as personal appearance and grooming standards. Early identification and treatment are of utmost importance in managing AKN in the military population to ensure reduction of morbidity, prevention of late-stage disease, and continued fitness for duty. This article reviews the clinical features, epidemiology, and treatments available for management of AKN, with a special focus on the active-duty military population.
Clinical Features and Epidemiology
Acne keloidalis nuchae is a chronic inflammatory disorder characterized by the development of keloidlike papules, pustules, and plaques on the posterior neck and occipital scalp.6 Also known as folliculitis keloidalis nuchae, AKN is seen primarily in men of African descent, though cases also have been reported in females and in a few other ethnic groups.6,7 In black males, the AKN prevalence worldwide ranges from 0.5% to 13.6%. The male to female ratio is 20 to 1.7 Although the exact cause is unknown, AKN appears to develop from chronic irritation and inflammation following localized skin injury and/or trauma. Chronic irritation from close-shaved haircuts, tight-fitting shirt collars, caps, and helmets have all been implicated as considerable risk factors.6-8
Symptoms generally develop hours to days following a close haircut and begin with the early formation of inflamed irritated papules and notable erythema.6,7 These papules may become secondarily infected and develop into pustules and/or abscesses, especially in cases in which the affected individual continues to have the hair shaved. Continued use of shared razors increases the risk for secondary infection and also raises the concern for transmission of blood-borne pathogens, as AKN lesions are quick to bleed with minor trauma.7
Over time, chronic inflammation and continued trauma of the AKN papules leads to widespread fibrosis and scar formation, as the papules coalesce into larger plaques and nodules. If left untreated, these later stages of disease can progress to chronic scarring alopecia.6
Prevention
In the general population, first-line therapy of AKN is preventative. The goal is to break the cycle of chronic inflammation, thereby preventing the development of additional lesions and subsequent scarring.7 Patients should be encouraged to avoid frequent haircuts, close shaves, hats, helmets, and tight shirt collars.6-8
A 2017 cross-sectional study by Adotama et al9 investigated recognition and management of AKN in predominantly black barbershops in an urban setting. Fifty barbers from barbershops in Oklahoma City, Oklahoma, were enrolled and interviewed for the study. Of these barbers, only 44% (22/50) were able to properly identify AKN from a photograph. Although the vast majority (94% [47/50]) were aware that razor use would aggravate the condition, only 46% (23/50) reported avoidance of cutting hair for clients with active AKN.9 This study, while limited by its small sample size, showed that many barbers may be unaware of AKN and therefore unknowingly contribute to the disease process by performing haircuts on actively inflamed scalps. For this reason, it is important to educate patients about their condition and strongly recommend lifestyle and hairstyle modifications in the management of their disease.