STUDY Acne Keloidalis Is a Form of Primary Scarring Alopecia COL Leonard C. Sperling, MC, USA; Carri Homoky, MD; LTC Laura Pratt, MC, USA; Purnima Sau, MD Objective: To better define the pathogenesis of acne ke- lar or perifollicular microorganisms. The number and type loidalis (AK). of hairs were also recorded. Design: Prospective, blinded study of histologic mate- Results: The most common findings in the 19 histo- rial collected from 10 patients with clinically typical AK. logically abnormal specimens were perifollicular, chronic (lymphocytic and plasmacytic) inflammation, most in- Setting: Outpatient dermatology clinic of a military ter- tense at the level of the isthmus and lower infundibu- tiary care medical center. lum; lamellar fibroplasia, most marked at the level of the isthmus; complete disappearance of sebaceous glands, as- Patients: Ten male volunteers 18 years or older with sociated with inflamed or destroyed follicles; thinning of early AK lesions (1- to 4-mm firm papules on the lower the follicular epithelium, most marked at the level of the occipital/nuchal region). isthmus; and total epithelial destruction (superficial and deep), with residual “naked” hair fragments. Even some Data Source: Biopsy specimens from small, early le- “normal” specimens contained true follicular scars, dem- sions and from clinically uninvolved skin, studied his- onstrating that normal-appearing scalp skin had previ- tologically with transverse sectioning. ously been affected by the disease. Intervention: Three separate 4-mm punch biopsy Conclusions: Acne keloidalis is a primary form of scar- specimens of the scalp (lesional, perilesional, and ring alopecia, and many of the histologic findings closely “normal” scalp) were obtained from each volunteer. resemble those found in certain other forms of cicatri- The specimens were processed using transverse sec- cial alopecia. Extensive subclinical disease may be pres- tioning. ent in patients with AK and can account for some of the permanent hair loss. Overgrowth of microorganisms does Main Outcome Measures: The primary variables for not appear to play an important role in the pathogenesis data analysis were the presence or absence of the follow- of the disease. There is no etiologic relationship be- ing histologic features: premature loss of the inner root tween AK and pseudofolliculitis barbae. Therapies found sheath; eccentric placement of shaft, with thinning of the to be useful in other forms of inflammatory scarring alo- outer root sheath; lamellar fibroplasia surrounding the pecia are useful in the treatment of early AK. follicle; loss of sebaceous glands; evidence of follicular destruction or scarring; inflammation; and intrafollicu- Arch Dermatol. 2000;136:479-484 CNE KELOIDALIS (AK) was and posterior neck. In a minority of cases, first described by Kaposi1 lesions are more numerous on the vertex in 1869 as dermatitis pap- and crown; therefore, we have chosen to illaris capillitii. Kaposi use the term acne keloidalis without the From the Department of concluded that the dis- modifier nuchae. Initially, hairs can be seen Dermatology, Uniformed ease was “a peculiar idiopathic chronic in- exiting the papules. However, with time, Services University, Bethesda, A flammation and connective-tissue new for- the papules tend to coalesce and form firm Md (Dr Sperling); Dermatology mation in the cutis.”2 Bazin originated the hairless keloidlike protuberant plaques that Associates, Kingsport, Tenn term acne keloidalis in 1872,3 and it is still can be painful and cosmetically disfigur- (Dr Homoky); and used today, although some authors4 pre- ing. Abscesses and sinuses exuding pus can Dermatology Department, 5 Portsmouth Naval Medical fer the term folliculitis keloidalis. This dis- be present in advanced cases. Although Center, Portsmouth, Va order typically affects young black men and AK may be asymptomatic, mild symp- (Dr Pratt). Dr Sau is in private begins as small, smooth, firm papules, with toms of burning and itching are often pres- practice in Silver Spring, Md. occasional pustules, on the occipital scalp ent.3,5 Acne keloidalis has been rarely re- ARCH DERMATOL / VOL 136, APR 2000 WWW.ARCHDERMATOL.COM 479 ©2000 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/27/2021 ported to occur in black women and white men,2,6 but is at least 10 times more common in blacks than in whites.3 SUBJECTS AND METHODS The condition includes nearly 0.5% of all dermatologic cases in the black population.7 SUBJECTS Medical treatment for early papular lesions in- This study was approved by the Clinical Investiga- cludes intralesional injections of corticosteroids, topi- tion Committee and the Human Use Committee/ cal steroids, and topical or oral antibiotics (usually Institutional Review Board of the Walter Reed Army tetracycline).5,6,8,9 In some cases, medical treatment is Medical Center, Washington, DC. All subjects en- 10 rolled in the study voluntarily agreed to participate successful in controlling the condition. Once large ke- and gave written informed consent. loidlike plaques have developed, the condition is resis- Ten male volunteers 18 years or older with early tant to all medical treatment, often requiring surgical 11,12 AK lesions (1- to 4-mm firm papules on the lower oc- removal. cipital/nuchal region) were recruited from the derma- The cause of AK remains unclear. Constant irrita- tology clinic of the Walter Reed Army Medical Cen- tion by shirt collars,2,8 low-grade bacterial infection,8 in- ter. Cases were collected over a 2-year period. Patients jury during short haircuts,3,5 curved hair and hair fol- who had been treated for AK with oral medications licles,8,9 and an autoimmune process3 have all been within 6 months or who had large keloidlike nodules suggested as pathogenic mechanisms. Thus far, none of or plaques were excluded. If patients had been using these theories has been proven, and all are based on cir- topical antibiotics or corticosteroids, there was a 3-week cumstantial evidence. The notion that lesions of AK are period during which they were off all medications be- 13 fore scalp biopsy specimens were obtained. caused by ingrowing hairs, analogous to the situation in pseudofolliculitis barbae,14 persists, despite the fact that METHODS there is no evidence to support this hypothesis.3 There Three 4-mm punch biopsy specimens of the scalp were is considerable evidence to the contrary,15 and our find- obtained from each volunteer. Each biopsy site was ings conclusively separate the pathogenic mechanisms anesthetized with 1% lidocaine and 1:100 000 epi- of AK and pseudofolliculitis barbae. nephrine. The first biopsy specimen, called lesional, was Histologic evaluation of AK has been performed in a discrete papule taken from clinically involved skin a few published cases, but the exact sequence of inflam- on the lower occiput/nuchal region. The second bi- matory events in this disorder has not been well de- opsy specimen, called perilesional, was taken from nor- fined. Often the small papular lesions seen early in the mal-appearing scalp skin, within 1 cm of the lesional specimen. The third biopsy specimen, called normal, disease clinically demonstrate histologically advanced was taken from the parietal scalp 4 cm superior to the stages of inflammation, making it difficult to determine apex of the left ear. The specimens were placed in 10% the earliest and perhaps triggering events in the disease formalin and processed using transverse sectioning.16 process.15 Multiple levels from each specimen were examined. Specimen labels were coded in a random fashion so that RESULTS the dermatopathologists were blinded to both the pa- tient and the type of biopsy specimen (lesional, per- Data on specimens showing abnormal pathologic char- ilesional, or normal skin). Any specimen demonstrat- acteristics are presented in the Table. Nine of 10 speci- ing inflammation or scarring was also stained to exclude fungus (periodic acid–Schiff and methenamine sil- mens from lesional skin, 4 of 10 specimens from perile- ver) and bacteria (Brown and Hopps, and Brown and sional skin, and 6 of 10 specimens from clinically normal Brenn). All histologic specimens were reviewed by the skin were histologically abnormal. The most consistent same 2 dermatopathologists (L.C.S. and P.S.). findings among these 19 histologically abnormal speci- mens were as follows: perifollicular chronic (lympho- DATA ANALYSIS cytic and plasmacytic) inflammation, most intense at the The small number of subjects used in this protocol level of the isthmus and lower infundibulum (n = 18; was based on the expectation of a large difference in Figure 1); complete disappearance of sebaceous glands the histopathologic features of diseased and normal associated with inflamed or destroyed follicles (n = 16); sites and the difficulty in obtaining multiple biopsy thinning of the follicular epithelium, most marked at the specimens from otherwise healthy subjects. level of the isthmus (n = 15; Figure 2); lamellar fibro- Presentation of data is primarily descriptive, pro- viding results of histopathologic analysis through pho- plasia, most marked at the level of the isthmus (n = 14; tomicrographs and a table. The primary variables for focal or total epithelial destruction (superficial and data analysis are the presence or absence of the follow- deep), with residual “naked” hair fragments (n = 11; ing histologic features: premature loss of the inner root Figure 3); dilatation of the follicular canal