Acne keloidalis nuchae (AKN) is a chronic, scarring form of folliculitis that develops on the back of the scalp and upper neck, producing firm bumps, thickened plaques, and sometimes large masses that can cause permanent hair loss. Despite its name, AKN is neither a type of acne nor a true keloid. It overwhelmingly affects men of African descent, though it also occurs in Hispanic men and occasionally in other populations. The condition tends to start small and worsen over time, and it carries a surprisingly strong link to metabolic health problems that most people with AKN never hear about.
Who Gets AKN and How Common Is It
AKN is one of the more common skin conditions seen in dermatology clinics serving Black populations, yet it remains poorly recognized in broader medical practice. Reported prevalence ranges widely depending on the population studied. In Nigeria, estimates run from about 0.7 percent to 9.4 percent; in South Africa, roughly 5 percent of boys in their final year of school and about 10 percent of older men are affected.1Clinical, Cosmetic and Investigational Dermatology. Acne keloidalis nuchae: prevalence, impact, and management challenges Among African Americans, prevalence has been reported anywhere from 0.5 percent up to 13.6 percent, with that high figure coming from a study of football players who wore tight-fitting helmets.2PubMed. Prevalence of acne keloidalis nuchae in football players Their white teammates wearing the same helmets did not develop the condition, which underscores how strongly ethnic background and hair type influence susceptibility.
The male-to-female ratio sits around 20 to 1, making AKN an overwhelmingly male condition.3Clinical, Cosmetic and Investigational Dermatology. Acne keloidalis nuchae: prevalence, impact, and management challenges Women do develop it, but cases are rare enough that they tend to show up as individual case reports in the literature. In one large retrospective study, all patients were non-white men, with about 58 percent of African descent and 37 percent Hispanic.4Journal of Clinical and Aesthetic Dermatology. A Retrospective Cohort Study and Clinical Classification System of Acne Keloidalis Nuchae AKN has also been documented in Asian patients, though less frequently.5PLoS ONE. Acne keloidalis nuchae in Asian: A single institutional experience
What Causes It
The honest answer is that nobody knows the exact cause. The prevailing theory centers on curved hair shafts that re-enter the skin after being cut short, triggering an inflammatory reaction. The body treats the ingrown hair as a foreign object, launching a cycle of inflammation and scarring that feeds on itself. But that explanation does not account for everyone who gets AKN, and the condition shows up in people who have never had a close haircut.
Several factors seem to contribute. Androgens likely play a role, which helps explain the heavy male skew. Mechanical friction from shirt collars, helmets, and headrests has long been suspected as a trigger or aggravator. The football helmet study is one of the more striking examples: the constant rubbing and sweating under protective headgear pushed prevalence to nearly 14 percent in Black players.6PubMed. Prevalence of acne keloidalis nuchae in football players Under a microscope, the hallmark is chronic inflammation around the hair follicle, concentrated at its mid-portion, with dense scar tissue forming around destroyed follicles and sebaceous glands disappearing.7PubMed Central. Acne keloidalis nuchae: prevalence, impact, and management challenges
Bacteria like Staphylococcus aureus and fungi like Malassezia have been found in AKN lesions, but their role appears to be secondary rather than causative. They colonize already-damaged skin and can worsen things, leading to pustules, draining sinuses, and abscesses, but they do not seem to start the process.8PubMed Central. Acne keloidalis nuchae: prevalence, impact, and management challenges Certain medications, including cyclosporine and some anti-seizure drugs, have been linked to AKN in individual cases, though this is uncommon.
The Metabolic Syndrome Connection
One of the more surprising findings about AKN is how strongly it correlates with metabolic problems. A large population-based study comparing roughly 2,700 AKN patients to over 13,000 controls found that metabolic syndrome was about two and a half times more common in people with AKN. Obesity showed the strongest link, with about three times the odds of being present in AKN patients. Type 2 diabetes, high blood pressure, and abnormal cholesterol levels were all significantly more common as well.9PubMed. Acne Keloidalis Nuchae and the Metabolic Syndrome: A Population-Based Study
This does not mean obesity causes AKN or vice versa, but the association is strong enough that researchers have proposed a plausible mechanism. Excess fat tissue at the nape of the neck, which is the only part of the scalp that moves freely with head rotation, may create skin folds that increase friction and trap moisture, setting the stage for the inflammation that drives AKN.10PubMed Central. High Frequency of Obesity in Acne Keloidalis Nuchae Patients: A Hypothesis from a Brazilian Study Whether or not that hypothesis holds up, the practical takeaway is worth knowing: if you have AKN, it may be worth getting screened for blood sugar, blood pressure, and cholesterol issues, since these conditions often go undetected in younger men.
What AKN Looks and Feels Like
AKN typically starts with small, firm bumps on the back of the scalp near the hairline. At this early stage, the bumps may itch or feel tender, and they can be mistaken for ordinary razor bumps or folliculitis. Without treatment, these papules can merge into larger plaques and, in some people, grow into sizable masses. A clinical classification system developed to standardize how doctors describe the condition sorts lesions into tiers based on their size, type, and spread. The most common presentation in one large study was moderate disease covering a sagittal width of about 4.5 centimeters.11Journal of Clinical and Aesthetic Dermatology. A Retrospective Cohort Study and Clinical Classification System of Acne Keloidalis Nuchae
As the condition advances, scarring destroys the hair follicles in the affected area, producing patches of permanent hair loss. In severe cases, thick ropy folds of skin called cutis verticis gyrata can form on the scalp, and draining nodules with scarring can spread beyond the classic nape location.12PubMed Central. A Candidate Syndromic Triad of Acne Keloidalis Nuchae, Dissecting Cellulitis, and Secondary Cutis Verticis Gyrata People of African descent in the study population showed a greater tendency to develop these tumorous masses compared to Hispanic patients.13Journal of Clinical and Aesthetic Dermatology. A Retrospective Cohort Study and Clinical Classification System of Acne Keloidalis Nuchae
AKN also overlaps with other scarring conditions of the scalp. About 7 percent of patients in one study had co-existing folliculitis decalvans or dissecting cellulitis, both of which cause their own patterns of hair loss and scarring.14Journal of Clinical and Aesthetic Dermatology. A Retrospective Cohort Study and Clinical Classification System of Acne Keloidalis Nuchae Interestingly, patients often did not know they had these additional conditions. Self-reported rates were lower than what clinicians found on examination, and about two out of five patients who thought they had been previously diagnosed with folliculitis decalvans had actually been diagnosed incorrectly.
The Barbershop Problem
Grooming is a central and thorny issue for people with AKN. Close haircuts are strongly associated with the condition, and most patients in studies had their hair cut with clippers very close to the scalp, a process that frequently caused symptoms to flare.15PubMed. Folliculitis keloidalis nuchae is associated with the risk for bleeding from haircuts The problem is that short, tapered haircuts are a dominant style in many of the communities where AKN is most prevalent, making avoidance a significant cultural and social ask.
Bleeding during haircuts is especially concerning. Active lesions on the nape often bleed when clippers pass over them, and in barbershops where multiple clients share clipping instruments, this creates a genuine risk of transmitting blood-borne infections.16PubMed Central. Acne keloidalis nuchae: prevalence, impact, and management challenges This is not a theoretical concern. Barbers in some settings reuse blades or clippers without adequate sterilization between clients, and AKN lesions are fragile enough that even careful clipping can draw blood.
The standard preventive advice is to avoid cutting hair on the nape shorter than about a finger-width, to skip tight collars and headgear when possible, and to minimize friction at the back of the neck. Some dermatologists recommend that patients with early-stage AKN switch to longer hairstyles altogether. For many men, though, this recommendation runs up against personal preference, professional norms, and cultural identity in ways that make compliance difficult.
Treatment for Early-Stage Disease
AKN is significantly easier to manage when caught early. Once thick plaques and masses form, the condition becomes much harder to treat with standard medical approaches.17PubMed Central. Treatment of Acne Keloidalis Nuchae by Simply Combining Two Conventionally Available Modalities First-line treatment typically involves a combination of topical or injected corticosteroids to reduce inflammation, antibiotics to address any secondary infection, and sometimes topical retinoids to reduce follicular plugging.18PubMed Central. Treatment of Acne Keloidalis Nuchae: A Systematic Review of the Literature
For pustules, draining sinuses, or signs of bacterial infection, antibiotics are usually started before or alongside steroid injections. Tetracycline-class antibiotics are a common choice for their combined anti-bacterial and anti-inflammatory properties.19PubMed Central. Treatment of Acne Keloidalis Nuchae: A Systematic Review of the Literature Oral isotretinoin, the medication best known for treating severe cystic acne, has been tried in AKN. It helped reduce active inflammation, but it did not do much for the follicular tufting or the hard, hyperkeratotic bumps that define the condition’s chronic stage.
Less commonly used options include cryotherapy (freezing), phototherapy, and even low-dose radiotherapy.20Dermatologic Therapy. Comorbidities and Treatment Options for Acne Keloidalis Nuchae Radiotherapy sounds aggressive for a skin condition, but it has been used in refractory cases, particularly when lesions recur after surgical removal.21PubMed Central. Acne keloidalis nuchae: A role for low-dose radiotherapy These are niche options, and the evidence base for each is thin compared to conventional approaches.
Laser Treatment and Hair Removal
Laser therapy has become one of the more promising approaches to AKN, particularly for papular disease. The logic is straightforward: if ingrown hairs perpetuate the inflammatory cycle, permanently reducing hair in the affected area should break that cycle. Long-pulsed Nd:YAG lasers, which penetrate deep enough to reach hair follicles in darker skin without excessive surface damage, are the workhorse for this approach.
In a controlled trial, the laser-treated side of the scalp showed about a 49 percent improvement in disease scores compared to about 33 percent on the untreated control side. For patients with only papules and no plaques or nodules, the difference was even more pronounced: roughly 59 percent improvement on the laser side versus about 30 percent on the control side.22PubMed. Prospective Controlled Trial for the Treatment of Acne Keloidalis Nuchae With a Long-Pulsed Neodymium-Doped Yttrium-Aluminum-Garnet Laser Larger plaques and nodules responded poorly to laser alone, which makes sense: once dense scar tissue has formed around trapped hair fragments, the laser cannot penetrate deep enough to reach the buried hairs.
This has led clinicians to recommend a staged approach that matches treatment to the type of lesion. For early papules, laser hair reduction can thin and weaken remaining hairs so they can no longer pierce back into the skin, reducing new eruptions. It also destroys hair fragments already embedded in the upper dermis, removing the stimulus for ongoing inflammation.23PubMed Central. Multimodality Surgical Treatment Approach to Acne Keloidalis Nuchae Based on Lesion Morphology For thicker lesions, the scar tissue itself usually needs to be physically removed first, with laser reserved for preventing recurrence in the surrounding skin. Some practitioners have also combined CO2 laser ablation with steroid injections, essentially vaporizing scar tissue and then injecting the wound bed to discourage it from reforming.24PubMed Central. Treatment of Acne Keloidalis Nuchae by Simply Combining Two Conventionally Available Modalities
Laser hair removal as a standalone cure has been described in selected patients with early, papular disease who meet specific criteria.25JAAD Case Reports. Selection criteria and techniques for improved cosmesis and predictable outcomes in laser hair removal treatment of acne keloidalis nuchae But for anyone with established plaques or masses, expecting laser alone to resolve the problem is unrealistic.
Surgery for Advanced Disease
When AKN has progressed to large plaques or tumorous masses, surgery is often the only effective option. The affected tissue is excised down to healthy margins, removing both the scar tissue and the destroyed follicles trapped within it. The surgical wound can be closed with sutures, skin grafts, or simply left open to heal on its own through secondary intention healing, where the wound gradually fills in from the base up. That last approach, while it sounds crude, has been reported to produce good cosmetic results with little recurrence.26PubMed. Surgical excision of acne keloidalis nuchae with secondary intention healing
The challenge with surgery is recurrence. AKN has a stubborn tendency to come back, especially at the margins of excision sites where remaining follicles can restart the cycle. This is why many surgeons now combine excision with post-operative laser hair reduction in the surrounding skin, or with steroid injections at the wound margins, to lower the odds of regrowth. In severe cases with bulky recurrent disease, low-dose radiotherapy after excision has shown promise in preventing recurrence, though the long-term safety data for radiotherapy in this context is limited.27PubMed Central. Acne keloidalis nuchae: A role for low-dose radiotherapy
Emotional and Social Toll
The psychological burden of AKN is substantial and largely underappreciated. The condition sits on the back of the head, visible to others but not to the person themselves in a mirror. It can be painful, it bleeds, it scars, and it permanently destroys hair. Many patients report embarrassment, anxiety, and depression related to their AKN, and the disfiguring nature of advanced disease affects how people feel about themselves in social and professional settings.28British Journal of Dermatology. BH05 Acne keloidalis nuchae: addressing diagnostic and treatment gaps in a high-risk population
Despite this, mental health support remains largely absent from routine AKN care. Dermatologists understandably focus on the physical disease, but the emotional dimension is real. Young men who develop AKN in their teens or twenties face decades of managing a visible, chronic condition that limits their hairstyle choices and requires ongoing treatment. For many, the condition also intersects with race in uncomfortable ways: AKN is overwhelmingly a disease of Black men, yet the dermatology workforce does not reflect that demographic, and research funding for the condition has historically been thin.
Why AKN Is Often Misdiagnosed or Diagnosed Late
A recurring theme in the AKN literature is how frequently the condition goes unrecognized. In one study, only three out of eight patients who were confirmed to have AKN in the clinic had ever received a prior diagnosis. And among patients who had previously been told they had a related condition, folliculitis decalvans, about two in five had been misdiagnosed.29Journal of Clinical and Aesthetic Dermatology. A Retrospective Cohort Study and Clinical Classification System of Acne Keloidalis Nuchae The rates of co-existing regular acne (39 percent) and razor bumps of the beard, known as pseudofolliculitis barbae (27 percent), were high in the same population, which may contribute to diagnostic confusion. If a patient already has bumps on the face from razor irritation, a doctor might lump the neck lesions into the same diagnosis without looking more carefully.
The distinction matters because treatments differ. Razor bumps on the beard generally respond to changes in shaving technique and topical retinoids. AKN involves a deeper scarring process that, left untreated, can progress to a point where topical therapy is no longer effective. Early recognition and early intervention remain the single most impactful factor in outcomes, and that starts with both patients and clinicians knowing what AKN looks like before it reaches an advanced stage.
Histology of Early Versus Late Lesions
The tissue-level changes in AKN help explain why early and late disease behave so differently in response to treatment. In early pustular and papular lesions, the area around inflamed follicles shows active growth of new connective tissue in a loose, fluid-rich matrix, with dilated blood vessels and mild inflammatory cell infiltration. The overall structure of the skin’s collagen layer is still largely preserved at this point.30PLoS ONE. Acne keloidalis nuchae in Asian: A single institutional experience
In later-stage plaque lesions, the picture changes dramatically. The loose, cellular tissue has been replaced by dense, relatively acellular scar tissue surrounding the areas of inflammation. Blood vessels are still dilated, but now the infiltrating cells are heavily dominated by plasma cells, suggesting a more established immune response. This dense fibrosis is what makes advanced AKN so resistant to medical therapy and why it often requires physical removal. The collagen is no longer soft or responsive; it has hardened into the firm, rubbery plaques that characterize chronic disease. Understanding this progression underscores why dermatologists push so hard for early treatment. The window during which medications can meaningfully alter the disease’s course is real, and it closes as the scarring matures.