Deeper thoughts about acne keloidalis nuchae

By Warren R. Heymann, MD, FAAD, February 1, 2026

Vol. 8, No. 2

Wallace Clark taught me the truism that thinking often ceases when a diagnosis is rendered. The clinical diagnosis of acne keloidalis nuchae (AKN) is straightforward. Embarrassingly, I had not given much thought about the pathogenesis of AKN beyond my residency, until hearing lectures about the disorder at the Pennsylvania Academy of Dermatology and the American Society of Dermatopathology meetings in the autumn of 2024. This commentary focuses on newer insights about the pathogenesis and treatment of AKN.

First described by Kaposi in 1869 as dermatitis papillaris capillitii, Bazin originated the term acne keloidalis in 1872.(1) The term AKN is a misnomer — it is not acne, a true keloid, nor are all cases on the neck; regardless, the term AKN is firmly entrenched in the literature. AKN usually affects those with darkly pigmented skin, especially people of African descent. The disorder primarily affects the young age group, with a male-to-female ratio of approximately 20:1.(2) In a retrospective study of 142 AKN Hispanic patients, 98% were male (n=140) with a mean age of 32 years.(3) Dermatologists will recognize the firm, dome-shaped, inflammatory papules, and pustules characteristically appearing on the nape of the neck. Subsequently, fibrosis may develop into keloidal papules, nodules, and plaques.(2)

Histopathologic examination is not required to secure the diagnosis of AKN, but when performed, the following features are observed: perifollicular, chronic (lymphocytic and plasmacytic) inflammation, most intense at the level of the isthmus and lower infundibulum; lamellar fibroplasia, most marked at the level of the isthmus; complete disappearance of sebaceous glands, associated with inflamed or destroyed follicles; thinning of the follicular epithelium, most marked at the level of the isthmus; and total epithelial destruction (superficial and deep), with residual “naked” hair fragments.(1) These fragments incite chronic granulomatous inflammation, which induces fibrosis.(3)

Although there are contributory factors that aggravate AKN (genetics, closely shaved or faded haircuts, use of sports or occupational headgear, tight collars), the etiology is unknown.(4) Sperling et al. recognized that AKN is a primary scarring alopecia due to the premature loss of the inner root sheath.(1) Umar et al. performed trichoscopy on 41 men with AKN. All patients showed signs of perifollicular erythema or scaling in normal-appearing scalp areas, correlating with histologic evidence of perifollicular infundibulo-isthmic lymphocytoplasmic infiltrates and fibrosis (PIILIF). PIILIF was often clinically mistaken for seborrheic dermatitis.(5) Hormonal influences may have a role in AKN, as exemplified by the case of a 38-year-old white woman with AKN with metabolic syndrome and autoimmune thyroiditis, whose AKN improved with treatment of her endocrine disorders.(6) Utilizing RNA sequencing, Hong et al. identified two notable populations: POSTN+ fibroblasts with enriched extracellular matrix signatures and SPP1+ myeloid cells with an M2 macrophage phenotype. Spatial transcriptomics and immunofluorescence staining verified microanatomic specificity of SPP1+ myeloid cells and POSTN+ fibroblasts with disease activity. The authors suggest that communication between POSTN+ fibroblasts and SPP1+ myeloid cells by SPP1 axis may contribute to the pathogenesis of acne keloidalis.(7)

Treating AKN focuses on the avoidance of aggravating factors, the use of topical agents (corticosteroids, calcineurin inhibitors, antibiotics, retinoids), systemic agents (antibiotics, isotretinoin), ablative therapies (laser, cryotherapy, radiotherapy), and surgery (excision, follicular unit excision), often in combination.(4) Intralesional triamcinolone (ILT) injections are standard of care. What piqued my attention was Prince Adotama’s lecture where he described a novel technique of injecting triamcinolone for AKN. According to Dr. Adotama, “Instead of focusing on injecting each individual lesion (intralesional method), the dermatologist can inject into the deep dermis of the general area of involvement. The clinician can inject 0.1-mL aliquots each into the deep dermis at 1-cm intervals using triamcinolone at a concentration of 5 to 10 mg/mL depending on disease severity until the entire area of involvement is completely treated. The maximum volume of triamcinolone at a concentration of 5 to 10 mg/mL injected per session is 20 mg. The clinician should inject both the active area and a 1-cm margin around the region to ensure effective treatment. This technique is similar to that used for alopecia areata, in which triamcinolone at a concentration of 10 mg/mL is injected intradermally at 1-cm interval with an injection volume of 0.05 to 0.1 mL per site and a maximum volume of 2 mL (20 mg) injected per session. In addition to our deep dermis injection method, the clinician can still inject directly into the lesion for more indurated exophytic papulonodules. A combination of the intralesional method for nodular and keloidal AKN and our deep dermis injection method for flat papular forms of AKN may improve overall outcomes. In our experience, this method leads to rapid and effective outcomes. Although complication rates are low in our experience, clinicians should still monitor for atrophy, telangiectasias, and dyspigmentation.”(8)

Before these lectures, I mistakenly viewed AKN as a variant of pseudofolliculitis barbae and would treat the disorder with ILT in the minute follicular papules. Now I understand that AKN is a primary scarring alopecia that may respond best to deeper injections of triamcinolone. Wallace would be proud that I started to think about AKN, albeit 40 years late.

Point to Remember: Acne keloidalis nuchae is a primary scarring alopecia that may improve with deeper injections of dermal injections of triamcinolone.

Our expert’s viewpoint

Prince Adotama, MD, FAAD
Assistant Professor, Ronald O. Perelman Department of Dermatology at NYU Grossman School of Medicine
Assistant Program Director, Dermatology Residency Program

Acne keloidalis nuchae (AKN) is often grouped together with pseudofolliculitis barbae (PFB), but these are two very distinct conditions. Unlike PFB, AKN is not as well recognized with only 44% of barbers adequately diagnosing this condition.(9) AKN is much more complex and the overall pathogenesis is poorly understood. Studies have found a strong association of AKN with obesity, hypertension, type 2 diabetes mellitus, dyslipidemia, and even hypothyroidism.(10-12)

While shaving still plays a pivotal role in AKN, the immune reaction that ensues after the inciting trauma may lead to a primary cicatricial alopecia.(13,1) Even in the clinically normal surrounding areas of the scalp of AKN patients, biopsies revealed true follicular scars and displayed signs of perifollicular fibroplasia with chronic inflammation.(1) With this understanding, simply injecting directly into lesions may not be adequate in fully controlling disease activity. As opposed to focusing on injecting each individual lesion (intralesional method), the dermatologist may instead inject into the deep dermis of the general area of involvement. For papular variants of AKN, our clinic injects 0.1 cc aliquots of 5-10mg/mL of triamcinolone into the deep dermis at 1-cm intervals to the entire area of involvement. Clinicians should also consider injecting a small margin outside of the clinically apparent area. In our experience, this method leads to rapid and effective outcomes. For the keloid stage of AKN, however, intralesional triamcinolone injections are still recommended, and higher doses up to 40mg/mL may be needed.(8)

Patients often come to my office seeking treatment after being turned away by other clinicians. However, a variety of treatments are available for AKN, including standard application of topical retinoids, Nd:YAG laser therapy for papular subtypes, and even surgical excisions for the more extensive keloidal variants.(14, 15)

Michelen-Gomez et al. recently repurposed the use of over-the-counter topical diclofenac sodium gel by applying it twice daily on the scalp of AKN patients.(16) I have also added this to my repertoire of treatments and found variable success. It is an exciting time to be a clinical researcher for cicatricial alopecia as more treatments are on the rise. Bao et al. found a novel treatment option for central centrifugal cicatricial alopecia (CCCA) with new data showing low-dose oral metformin improves not only clinical outcomes in CCCA but also reduces profibrotic signatures and inflammatory markers.(17) As we learn more and more about these various primary cicatricial alopecias, we can develop and provide more comprehensive and innovative solutions for our patients.

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References

1. Sperling LC, Homoky C, Pratt L, Sau P. Acne keloidalis is a form of primary scarring alopecia. Arch Dermatol. 2000 Apr;136(4):479-84. doi: 10.1001/archderm.136.4.479. PMID: 10768646.

2. Al Aboud DM, Badri T. Acne Keloidalis Nuchae. 2023 Jul 31. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan–. PMID: 29083612.

3. Sánchez-Dueñas LE, Ungson-García MG, Ramírez-Sánchez JA, Barrera AMA, Machado MM, Ocampo-Garza SS, Rojano-Fritz LK, Gálvez-Canseco A, López LEB, Mendoza DG, Yepiz RC, Delgadillo AA, Miranda YM. Acne Keloidalis Nuchae: A Multicenter Retrospective Study of 142 Hispanic Patients. Dermatol Pract Concept. 2024 Jul 1;14(3):e2024198. doi: 10.5826/dpc.1403a198. PMID: 39122530; PMCID: PMC11313964.

4. Pozo DD, Usatine RP, Heath CR. Moving Beyond Traditional Methods for Treatment of Acne Keloidalis Nuchae. Cutis. 2024 Sep;114(3):88-89. doi: 10.12788/cutis.1083. PMID: 39413321.

5. Umar S, Ton D, Carter MJ, Shitabata P. Unveiling a Shared Precursor Condition for Acne Keloidalis Nuchae and Primary Cicatricial Alopecias. Clin Cosmet Investig Dermatol. 2023 Aug 25;16:2315-2327. doi: 10.2147/CCID.S422310. PMID: 37649568; PMCID: PMC10464825.

6. Anatolieva B, Kirov V, Ganeva S. Acne Keloidalis Nuchae in a Caucasian Non-Hispanic Woman With Metabolic Syndrome and Autoimmune Thyroiditis: A Case Report. Cureus. 2024 Apr 27;16(4):e59119. doi: 10.7759/cureus.59119. PMID: 38803744; PMCID: PMC11128944.

7. Hong YK, Hwang DY, Yang CC, Cheng SM, Chen PC, Aala WJ, I-Chen Harn H, Evans ST, Onoufriadis A, Liu SL, Lin YC, Chang YH, Lo TK, Hung KS, Lee YC, Tang MJ, Lu KQ, McGrath JA, Hsu CK. Profibrotic Subsets of SPP1+ Macrophages and POSTN+ Fibroblasts Contribute to Fibrotic Scarring in Acne Keloidalis. J Invest Dermatol. 2024 Jul;144(7):1491-1504.e10. doi: 10.1016/j.jid.2023.12.014. Epub 2024 Jan 11. PMID: 38218364.

8. Adotama P, Grullon K, Ali S, Okoye GA. How We Do It: Our Method for Triamcinolone Injections of Acne Keloidalis Nuchae. Dermatol Surg. 2023 Jul 1;49(7):713-714. doi: 10.1097/DSS.0000000000003803. Epub 2023 Apr 11. PMID: 37040497.

9. Adotama P, Tinker D, Mitchell K, Glass DA 2nd, Allen P. Barber Knowledge and Recommendations Regarding Pseudofolliculitis Barbae and Acne Keloidalis Nuchae in an Urban Setting. JAMA Dermatol. 2017 Dec 1;153(12):1325-1326. doi: 10.1001/jamadermatol.2017.3668. PMID: 29049485; PMCID: PMC5817432.

10. Kridin K, Solomon A, Tzur-Bitan D, Damiani G, Comaneshter D, Cohen AD. Acne Keloidalis Nuchae and the Metabolic Syndrome: A Population-Based Study. Am J Clin Dermatol. 2020 Oct;21(5):733-739. doi: 10.1007/s40257-020-00541-z. PMID: 32748304.

11. Saka B, Teclessou JN, Akakpo SA, Pessinaba S, Gnossike P, Mahamadou G, Kassang P, Mouhari-Toure A, Kombate K, Pitché P. Acne keloidalis nuchae and hypertension in black subjects: a case-control study. BMC Res Notes. 2020 Sep 14;13(1):431. doi: 10.1186/s13104-020-05274-0. PMID: 32928290; PMCID: PMC7491137.

12. Valdman-Grinshpoun Y, Kridin K, Schonmann Y, Cohen AD. Acne keloidalis nuchae and thyroid diseases: a population-based cohort study. Int J Dermatol. 2021 Apr;60(4):466-470. doi: 10.1111/ijd.15331. Epub 2020 Dec 10. PMID: 33301179.

13. Maranda EL, Simmons BJ, Nguyen AH, Lim VM, Keri JE. Treatment of Acne Keloidalis Nuchae: A Systematic Review of the Literature. Dermatol Ther (Heidelb). 2016 Sep;6(3):363-78. doi: 10.1007/s13555-016-0134-5. Epub 2016 Jul 18. PMID: 27432170; PMCID: PMC4972740.

14. Woo DK, Treyger G, Henderson M, Huggins RH, Jackson-Richards D, Hamzavi I. Prospective Controlled Trial for the Treatment of Acne Keloidalis Nuchae With a Long-Pulsed Neodymium-Doped Yttrium-Aluminum-Garnet Laser. J Cutan Med Surg. 2018 Mar/Apr;22(2):236-238. doi: 10.1177/1203475417739846. PMID: 29587518.

15. Glenn MJ, Bennett RG, Kelly AP. Acne keloidalis nuchae: treatment with excision and second-intention healing. J Am Acad Dermatol. 1995 Aug;33(2 Pt 1):243-6. doi: 10.1016/0190-9622(95)90242-2. PMID: 7622651.

16. Michelen-Gómez EA, Chiesa Fuxench ZC, Cancel-Artau KJ, Guerrero A, Ibrahim O, Santaliz-Ruiz LE 4th, Colon-Fontanez F. Treatment of acne keloidalis nuchae and dissecting cellulitis of the scalp with diclofenac sodium gel: a case series. JAAD Case Rep. 2023 Sep 27;42:113-116. doi: 10.1016/j.jdcr.2023.09.008. PMID: 38090660; PMCID: PMC10711382.

17. Bao A, Qadri A, Gadre A, Will E, Collins D, Ahima R, Bordone LA, Aguh C. Low-Dose Metformin and Profibrotic Signature in Central Centrifugal Cicatricial Alopecia. JAMA Dermatol. 2024 Nov 1;160(11):1211-1219. doi: 10.1001/jamadermatol.2024.3062. PMID: 39230880; PMCID: PMC11375521.

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