Acne Keloidalis Nuchae (AKN) is a chronic inflammatory skin condition primarily affecting the hair follicles at the back of the neck and the lower part of the scalp, known as the occipital area. It is a form of scarring folliculitis that progresses slowly over time. This condition is characterized by an inflammatory response that ultimately leads to the formation of hard, raised, keloid-like scars in the affected area.
Defining Acne Keloidalis Nuchae
AKN begins with the appearance of small, firm, and often itchy bumps at the nape of the neck and the occipital scalp. These lesions, which are distinct from acne vulgaris, are follicular-based papules and pustules. The initial inflammation is centered around the hair follicles, which become irritated and infected.
As the condition advances, chronic inflammation destroys the hair follicles, causing a foreign body reaction to released hair shafts within the skin. The body’s repair process overproduces collagen, causing the papules to harden and increase in size. These lesions often merge together to form firm, elevated, and thick plaques.
The progression of AKN results in symptoms including itching, tenderness, or pain, especially when the area is irritated. The chronic scarring ultimately destroys the hair follicles, leading to permanent hair loss within the affected patches of skin. In advanced stages, the plaques can become large tumor-like masses, sometimes developing deep pockets of pus called sinus tracts that may discharge fluid.
Identifying Underlying Causes and Risk Factors
The condition is fundamentally rooted in chronic inflammation of the hair follicles, known as folliculitis. This inflammation is often triggered by mechanical trauma that causes hair shafts to break and re-enter the skin, initiating a localized foreign body reaction. This process is distinct from the hormonal and oil-gland mechanisms responsible for typical acne.
The condition predominantly affects individuals with coarse, tightly curled hair. The sharp, curved nature of the hair shaft predisposes it to re-entering the skin after being cut short, leading to ingrown hairs that provoke an inflammatory response. AKN is highly prevalent in young men of African descent, though it can occur in any individual with this hair type.
Chronic friction and irritation to the nape of the neck also play a significant role in triggering or exacerbating the condition. Practices such as close shaving with clippers or razors create sharply angled hair ends, increasing the likelihood of hair re-entry. Constant rubbing from tight shirt collars, helmets, or neck-constricting gear can repeatedly traumatize the area and sustain the inflammatory cycle. Familial patterns suggest a genetic predisposition may also increase susceptibility to developing AKN.
Current Management and Treatment Approaches
Management focuses on reducing inflammation, preventing further scarring, and eliminating triggers that sustain the condition. Initial treatment involves lifestyle adjustments, such as avoiding close shaving in the affected area. Patients should also discontinue the use of tight-fitting headwear or collars that cause friction.
Topical medications are the first line of defense to control inflammation and infection. Potent topical corticosteroids, such as clobetasol, decrease redness and swelling within the papules. Topical antibiotics like clindamycin, or antimicrobial washes containing benzoyl peroxide, are often prescribed to prevent or treat secondary bacterial infections.
Oral medications are necessary to achieve better control over more extensive inflammation. Oral antibiotics, particularly tetracyclines, are often prescribed for their anti-inflammatory properties. In resistant cases, oral retinoids like isotretinoin may be used to reduce inflammation and keratin buildup within the hair follicles.
For established, firm lesions and plaques, procedural treatments are required to flatten the scars and prevent recurrence. Intralesional injections of corticosteroids are a standard procedure used to shrink the fibrotic plaques. Laser therapy, using devices like the 1064-nm Nd:YAG laser, can be effective as a hair removal method in the affected area to prevent the formation of new ingrown hairs and maintain remission.
In advanced cases where large, dense plaques or tumor-stage masses have formed, surgical intervention may be the most effective option. Surgical excision involves removing the scarred tissue, followed by primary closure or healing by secondary intention. This procedure can be combined with other treatments, such as laser ablation or intralesional steroids, to reduce the risk of recurrence at the surgical site.