Dissecting Cellulitis of the Scalp: Current Insights and Therapeutic Advances.

Dear Editor, Dissecting cellulitis of the scalp (DCS) is a chronic, recalcitrant skin condition that disproportionately affects African-American men.1 There is a lack of bibliometric data regarding DCS publications. Herein, we examined the characteristics of top cited DCS articles and evaluated DCS research trends over time. In January 2023, the Web of Science database was used to identify DCS-related publications using the following search terms: "dissecting cellulitis" OR "perifolliculitis capitis abscedens" OR "dissecting folliculitis" OR "Hoffman disease". Two independent authors (R.M. and E.M.) analyzed relevant articles for year of publication, authorship, country of origin, study topic, and study design. Any discrepancies were discussed to consensus with a third reviewer (J.L.H.). The database search resulted in a total of 324 articles. Table 1 shows the 50 most-cited articles. Most (70%, 35/50) of the highly cited papers were published between 2000–2019. The top cited article (cited 149 times) was a general narrative review on primary cicatricial alopecias published in the Journal of the American Academy of Dermatology (JAAD) in 2005. The article with the highest average citations per year (10.8) was a narrative review on trichoscopy published in the Journal of Dermatological Case Reports in 2011. The most highly cited study topic was DCS treatments, followed by diagnostic techniques and narrative review articles (Figure 1). Of the 26 articles that discussed treatments, 13 (50%) discussed medical treatments including oral retinoids (7), biologics (3), zinc (2), antibiotics (2), and anti-androgen drugs including cyproterone acetate and ethinyl estradiol (1). All studies on biologics were published between 2008–2015. Nine articles (34.6%) were on procedural treatments including lasers (4), surgical excisions with or without skin grafts (3),x-ray epilation (1), and radiation treatment (1). Four studies (15.4%) described both medical and procedural treatments. There were 12 articles focused on diagnosis, including dermoscopy (5), histopathology (5), dermoscopy and histopathology (1), and clinical features (1). Of the 50 articles, most were case reports/series (54%) followed by narrative reviews (30%), prospective/retrospective cohort studies (12%), and case-controlled studies (4%). In the past decade, there is an increasing trend of highly cited papers moving away from case reports/series and instead including case-controlled studies, retrospective cohort studies, and narrative reviews (Figure 2). The majority of the top 50 cited articles were from North America (44%, 22/50) or Europe (42%, 21/50). The JAAD and the British Journal of Dermatology had the highest number of top-cited articles (n = 8 each) followed by the Archives of Dermatology (n = 5). Top-cited DCS literature has grown exponentially over the last two decades, likely reflecting increased interest from researchers and clinicians. More than three-fourths (76%) of the top 50 highly cited articles discussed DCS diagnosis and treatment, reflective of both the diagnostic and therapeutic challenges that clinicians can face with distinguishing DCS from other scarring alopecias and with DCS management. In addition, during the past decade, there has been a shift in focus from case reports/series to more rigorous study types, such as case-controlled and cohort studies. However, no randomized controlled trials (RCTs) were amongst the top 50 cited papers; overall, there have been no RCTs for DCS reported in the literature.2 The pathogenesis of DCS is still under investigation. All three top-cited pathogenesis papers on DCS discussed DCS in the context of keratitis-ichthyosis-deafness (KID) syndrome. The association between this syndrome and the follicular occlusion tetrad merits further investigation. Of note, DCS shares many similarities with hidradenitis suppurativa (HS), and some studies have posited that the two diseases are different localizations of the same disease.3 HS has historically been a neglected disease, however, in the past decade, the number of clinical trials and publications on HS have grown exponentially. Though this renaissance has yet to be seen for DCS, given the similarities between and co-occurrence of the two conditions, patients with DCS may also benefit from expansion of HS treatment options. Most articles were from Western nations, indicating that more DCS research should be encouraged in underrepresented regions, particularly since skin of color patients are disproportionately affected by DCS. More comprehensive studies on DCS epidemiology are also needed, including wider representation from non-Western countries to better understand if different phenotypes of DCS exist. In addition, biologics, which have revolutionized the treatment of HS,4 merit further study in DCS as a potential long-term therapeutic option. To our knowledge, this study presents novel findings regarding bibliometric trends in DCS literature. Study limitations include that articles published recently may not have had much time to accumulate citations. Future investigations on DCS pathogenesis may shed insight on important genetic and environmental factors that can contribute to DCS initiation and progression and elucidate whether DCS and HS have overlapping inflammatory and mechanistic pathways. Larger prospective studies and RCTs are needed to guide treatment decisions for patients with DCS. This study has no funding source. V.Y.S. is on the board of directors for the Hidradenitis Suppurativa Foundation (HSF), an advisor for the National Eczema Association, is a stock shareholder of Learn Health and has served as an advisory board member, investigator, speaker, and/or received research funding from Sanofi Genzyme, Regeneron, AbbVie, Genentech, Eli Lilly, Novartis, SUN Pharma, LEO Pharma, Pfizer, Incyte, Boehringer Ingelheim, Alumis Aristea Therapeutics, Menlo Therapeutics, Dermira, Burt's Bees, Galderma, Kiniksa, UCB, Target-PharmaSolutions, Altus Lab/cQuell, MYOR, Polyfins Technology, GpSkin and Skin Actives Scientific. J.L.H. is on the Board of Directors for the Hidradenitis Suppurativa Foundation, has served as a consultant for AbbVie, Aclaris, Boehringer Ingelheim, Novartis, and UCB, as a speaker for AbbVie, and as an investigator for Amgen, Aristea, Boehringer Ingelheim, and Incyte. All other authors report no conflicts of interest.

Acne conglobata (AC), perifolliculitis capitis abscedens et suffodiens (PCAS) and hidradenitis suppurativa (HS) are uncommon refractory chronic, inflammatory, scarring diseases but cause serious damage to the quality of life. These three diseases are associated with follicular occlusion. Several studies indicated topical 5-aminolevulinic acid photodynamic therapy (ALA-PDT) improved follicular occlusion besides acne treatment. So we attempted to apply ALA-PDT to medicine resistant AC, PCAS and HS. Topical ALA-PDT was applied to 10 patients with AC, seven patients with PCAS and three patients with HS for more than three sessions. All the patients completed the dermatology life quality index (DLQI) questionnaire and were assessed for the efficacy at the baseline and on two weeks after each treatment. Adverse effects were recorded at each visit. The results showed 25.5% (5/20, two cases of AC and three cases of PCAS) of patients achieved excellent improvement after three sessions of PDT and another 60.0% (12/20, eight cases of AC and four cases of PCAS) of patients achieved good improvement. 15.0% (3/20, three cases of HS) got poor response ([Formula: see text] 20% lesions clearance). Another five cases (three cases of AC and two cases of PCAS) also achieved excellent response after 5–7 sessions of PDT. We also found that papular/nodular, cyst/abscess showed higher clearance rate than sinus/fistula (88.5%, 86.1% versus 11.1%). DLQI was reduced after three sessions of PDT in AC and PCAS patients rather than HS patients. 5-ALA-PDT could improve refractory AC and PCAS but could not lead to improvement in late stage of HS. The efficacy increased with more treatment sessions.

Dissecting cellulitis of the scalp (DCS) is a rare, primary neutrophilic cicatricial alopecia of unknown etiology. The disease follows a chronic, relapsing, and remitting course which may ultimately lead to scar formation and alopecia. The association of seronegative peripheral and/or axial spondyloarthritis in patients with hidradenitis suppurativa (HS) and acne conglobata (AC) is well established. However, the occurrence of spondyloarthropathy in patients with either isolated or combined DCS is relatively rare and therefore underrecognized by clinicians. We report a patient with DCS with inflammatory peripheral arthritis and asymptomatic radiographic sacroiliitis. Using PubMed, Ovid, and Google scholar, we searched for case reports of inflammatory arthritis in HS, AC, and DCS in the English literature from 1982 to present. We identified 12 patients with DCS who had associated spondyloarthropathy with adequate clinical details for a systematic analysis. We outline key clinical features, radiographic findings, and treatment utilized for these patients. Seronegative axial and peripheral spondyloarthritis may occur in the setting of isolated DCS as well with concomitant HS and AC. The inflammatory arthritis often develops during acute flares of the cutaneous disease. Choosing optimal drug therapy may be challenging. Current options include anti-TNF-α medications, which have been reported to be effective for both the cutaneous lesions and the associated spondyloarthritis. The complex pathophysiology of the conditions that comprise the follicular occlusion triad warrants further research into the potential role of additional biologic agents.

The effects of childhood obesity or weight gain on the development of early-onset follicular occlusion triad (FOT), which includes hidradenitis suppurativa (HS), acne conglobata (AC) and dissecting cellulitis of the scalp (DCS) in children, remain unknown. To investigate the association between body mass index (BMI) and changes in BMI and the development of early-onset FOT in children. This nationwide population-based longitudinal cohort study included a cohort of 2 012 928 Korean children who underwent two consecutive health examinations at 30-36 months and 42-48 months of age, respectively, between 2009 and 2020. BMI and changes in BMI were derived during these health screenings. We performed multivariate Cox proportional hazards regression analyses to estimate the risk of early-onset FOT, including HS, AC and DCS. During follow-up, 1283 FOT events, including 143 cases of HS, 1068 cases of AC and 72 cases of DCS, were identified. Children with obesity had an elevated risk of early-onset FOT than those with a normal weight [FOT: adjusted hazard ratio (aHR) 1.49, 95% confidence interval (CI) 1.21-1.84; HS: aHR 2.30, 95% CI 1.39-3.82; AC: aHR 1.36, 95% CI 1.07-1.73]. BMI gain was correlated with an elevated risk of early-onset FOT, particularly HS, whereas BMI loss was linked to a decreased risk of early-onset FOT, especially HS. Children who developed obesity had an increased risk of early-onset FOT (aHR 1.51, 95% CI 1.07-2.14) vs. those who maintained a normal weight. Children with obesity who reduced to a normal weight exhibited a decreased risk of early-onset FOT [FOT: aHR 0.41, 95% CI 0.17-0.96 (Ptrend = 0.02); HS: Ptrend = 0.05] than children with obesity who retained their weight. Childhood obesity is associated with an elevated risk of early-onset FOT, including HS and AC. Weight gain is correlated with an increased risk of early-onset FOT, especially HS, while weight loss is associated with a decreased risk of early-onset FOT, particularly HS. Implementing purposeful weight-reduction strategies may be helpful in preventing the development of early-onset FOT.

Acne inversa (AI) is a chronic recurrent inflammatory skin disease involving hair follicles and sebaceous glands. It is usually complicated by acne conglobata and perifolliculitis capitis abscedens et suffodiens. The main clinical manifestations are abscesses, sinuses, and scars in areas bearing apocrine sweat glands. The pathogenesis of AI is complicated and remains unclear so far, and its occurrence shows familial aggregation. Recently, great progress has been made in researches on clinical phenotypes and comorbidities of AI, such as rheumatic diseases, metabolic syndrome, inflammatory bowel diseases, and so on. The authors summarize its phenotypes and comorbidities, in hope to enhance understanding of this entity, so as to offer patients individualized systemic treatment strategies, and increase their quality of life. Key words: Hidradenitis suppurativa; Clinical phenotypes; Comorbidities; Complications

Hidradenitis suppurativa (HS) is a chronic inflammatory disorder affecting the hair follicle which typically affects the axilla, inguinal, submammary, and perianal areas. Atypical HS, such as facial HS, dissecting cellulitis of the scalp (DCS), nape HS, and HS lymphedema has also been described. There is scarce evidence about the treatment of atypical HS. To describe the efficacy of biologic drugs and adjuvant therapeutic interventions used in patients with atypical HS who had an inadequate response to systemic antibiotics. Prospective case series study of patients with atypical HS (facial HS, DCS, nape HS, and HS lymphedema) treated with biologic drugs in a HS Clinic setting. Disease activity indexes, sociodemographic, clinical, and safety variables were collected. Two patients met criteria for Facial HS, three met criteria for DCS/nape HS and three patients met criteria for HS lymphedema. Patients with facial HS achieved rapid improvement without requiring other therapies. Patients with DCS, nape HS, and HS lymphedema showed variable response, with decrease of activity indexes, and requiring adjuvant treatments. Biologic drugs are useful in the management of special HS locations. In the case of facial HS, biologic therapy seems to be quite effective as monotherapy. In the cases of DCS, HS lymphedema and nape HS, treatment combination or intensification may be needed.

Dissecting cellulitis of the scalp (DCS) is a chronic, relapsing neutrophilic scarring alopecia within the follicular occlusion spectrum. It shares clinical and pathogenic features with hidradenitis suppurativa (HS), acne conglobata, and pilonidal sinus disease, reflecting activation of convergent inflammatory pathways. Therapeutic decision-making is challenging because of the absence of specific guidelines and approved treatments. This review aimed to evaluate the efficacy and safety of advanced therapies-including biologic agents and small-molecule inhibitors-in DCS. In addition, therapeutic recommendations for disease management based on the available literature are proposed. A systematic review was performed to identify original studies, case series, and case reports reporting outcomes of tumor necrosis factor alpha antagonists (TNFα), interleukin (IL)-12/23, IL-17, IL-23 inhibitors, or small-molecule agents in DCS. Forty-six studies comprising 125 patients were analyzed. TNFα inhibitors were the most frequently used therapies and demonstrated overall response rates exceeding 80%. Adalimumab and infliximab were the most commonly reported agents. IL-17 and IL-23 inhibitors yielded encouraging results in refractory disease, whereas JAK inhibitors emerged as alternative options. The adverse event (AE) rate was 8.3%, predominantly mild or moderate. Advanced therapies-particularly TNFα inhibitors-appear effective and well tolerated for severe or refractory DCS. Earlier initiation of treatment may help modify the inflammatory disease course and potentially prevent irreversible scarring alopecia; however, this proposed benefit remains hypothesis-generating and warrants prospective validation.

Dissecting cellulitis of the scalp (DCS) is a rare inflammatory condition with a significant negative impact on quality of life.1 Treating DCS is crucial due to its chronic and progressive nature, as well as the high probability of permanent hair loss resulting from irreversible scarring. The usual treatment for DCS involves Isotretinoin and oral antibiotics, however, the effectiveness of the treatment can vary from person to person.1, 2 Recent studies have found that microneedle radiofrequency therapy can selectively destroy the sebaceous gland structure, subsequently reducing sebum secretion and achieving the effect of acne treatment.3 Considering that abnormal keratinization of follicular epithelium and follicular occlusion are the key mechanisms in the pathogenesis of DCS, microneedle radiofrequency might be the ideal alternative treatment option. Herein, we report a case of DCS that exhibited a rapid and favorable response to isotretinoin combined with single microneedle radiofrequency (SMRF). A 16-year-old teenager presented to our clinic with a 3-year history of several tender, fluctuant nodules on his head. Despite multiple courses of oral antimicrobial agents and Chinese traditional patent medicines, his symptoms persisted. On physical examination, multiple nodules with soft texture of the scalp were noted, accompanied by overlying alopecia (Figure 1A–C). The patient also suffered from moderate facial acne. There were no skin changes elsewhere. The diagnosis of DCS was clinical and based on skin examination. The patient was about to enter college, and he expressed his desire for a faster and more effective treatment. Treatment with isotretinoin (20 mg, divided twice daily) and SMRF (once every 2 weeks) was initiated. Dramatically, the scalp lesions subsided significantly 2 weeks later (Figure 1D–F), while SMRF was subsequently discontinued (four times in total). Isotretinoin was gradually tapered off and stopped within 6 months (Figure 2A–C), with no recurrence at 1 year follow-up. Other than temporary mucocutaneous dryness, no serious adverse events were reported during treatment. Although multifactorial in etiology, the mechanisms leading to DCS are not fully understood but likely involve a defect in follicular keratinization and sebaceous and keratinous material accumulates within dilated hair follicles, eventually leading to obstruction of the follicle and an intense neutrophilic inflammatory reaction.4 Therefore, targeting sebaceous glands becomes an ideal therapeutic strategy for DCS patients. Insulated and noninsulated microneedles arranged on a grid probe are used in SMRF to penetrate the skin and deposit energy from the needle lancet.3 An advantage of the system is that the therapeutic depth can be controlled, and the radiofrequency energy can be accurately delivered to the DCS deep hair follicle lesion through invasive microneedles to achieve the desired therapeutic effect. Another related advantage is that SMRF permanently damages the sebaceous gland structure, which greatly reduces the risk of local recurrence. In conclusion, Our case suggested that SMRF may be considered a potential treatment for DCS patients. However, the strength of this conclusion may be limited by the fact that this patient was treated in combination with isotretinoin. More studies are needed to fully appreciate the potential of SMRF for DCS. All authors contributed to the final manuscript. C-H L collected the clinical data and drafted the manuscript. Corresponding authors C-R Z read and revised the manuscript. All authors contributed to the articleand approved the submitted version. All authors thank the patient in this study. All authors declare that there are no competing interests associated with the manuscript. No additional data are available.

Dissecting cellulitis of the scalp (DCS) is a chronic, inflammatory follicular occlusion disorder characterized by painful nodules, abscesses, and sinus tracts that lead to scarring alopecia. The therapeutic goal is to limit disease progression and the extent of scarring. Although DCS is traditionally managed with systemic retinoids, antibiotics, and surgical interventions, therapeutic responses are variable and long-term remission remains challenging. Recent insights into the immunological overlap between DCS, hidradenitis suppurativa (HS), and other autoinflammatory follicular disorders have expanded therapeutic options, particularly with biologic agents targeting tumor necrosis factor alpha (TNF-α), interleukin (IL)-17, and IL-23 pathways, as well as Janus kinase (JAK) inhibitors. This review synthesizes the current evidence on medical, procedural, and emerging targeted therapies for DCS, incorporating data from case reports, case series, retrospective cohorts, and recent systematic reviews up to 2025. Special emphasis is placed on the evolving role of biologics and small-molecule inhibitors, which show growing promise for refractory or syndromic presentations. Current evidence supports a stepwise, phenotype-driven approach in which systemic retinoids remain first-line systemic therapy, while biologics represent a rational and increasingly evidence-supported option for moderate-to-severe, treatment-resistant, or syndromic disease. Further controlled studies are needed to define optimal sequencing, duration, and combination strategies for long-term management.

Perifolliculitis capitis abscedens et suffodiens (PCAS) is a rare scalp disease of unknown etiology which is hard to treat. It is often accompanied by scarring alopecia, acne conglobata, and recurrent fluctuant abscesses. PCAS belongs to the family of acne inversa (hidradenitis suppurativa). A 19-year-old man presented with PCAS for 2 years; multiple systemic antibiotic therapies and surgical approaches had shown no effect. Monotherapy with isotretinoin 80 mg daily for 4 weeks had not been successful. Combination therapy with dapsone 100 mg and isotretinoin 80 mg daily produced significant improvement. During 4 weeks of treatment significant clearing was achieved. Dapsone was reduced to 50 mg daily after 6 months, while isotretinoin was discontinued gradually. Now the patient is on dapsone 50 mg every other day and has remained free of recurrences for 6 months.

Introduction: Dissecting cellulitis of the scalp (DCS) is a neutrophilic scarring alopecia typically presenting with pustules and fluctuant nodules, followed by suppuration and sinus tract formation. DCS is often associated with other diseases, such as hidradenitis suppurativa (HS) and conglobate acne (CA) which share similar pathogenetic mechanisms. Case Presentation: The authors report the case of a patient affected by a severe form of DCS, HS, and CA of the face. Previous treatments with isotretinoin, antibiotics, and adalimumab did not have a considerable efficacy. Off-label treatment with secukinumab showed a gradual improvement in the clinical presentation bringing to a reduction in the number of HS lesions and to an almost complete resolution of the inflammatory manifestations of DCS. Conclusion: Management of DCS is challenging and is typically based on retinoids which are considered the first line of treatment. The efficacy of biologic drugs, especially TNFα inhibitors, in severe and relapsing forms of DCS has been reported in recent literature. To our knowledge, only one case of isolated DCS treated with secukinumab is reported. No cases of concomitant DCS and HS, treated with this type of IL-17 inhibitor, have been described.

Perifolliculitis capitis abscedens et suffodiens (PCAS) or dissecting cellulitis is a rare condition presenting deep follicular occlusions, follicular ruptures and follicular infections in the scalp area with unknown etiology, which consequently cause primary neutrophilic cicatricial alopecia by the repeated follicular inflammation. PCAS is categorized as one of the "follicular occlusion tetrad" along with hidradenitis suppurativa, acne conglobata and pilonidal cyst. In the pathogenesis of the follicular occlusion tetrad, the involvement of neutrophils and its activator tumor necrosis factor (TNF) have been discussed. Here, we report a case of PCAS that was successfully treated with adalimumab, a human anti-TNF monoclonal antibody. This is the first Asian case of PCAS that was improved by a TNF inhibitor.

Risk factors for dissecting cellulitis of the scalp: A case-control study

Squamous cell carcinoma arising in dissecting perifolliculitis of the scalp. A case report and review of secondary squamous cell carcinomas.

Hidradenitis suppurativa (HS) had several different names in the past due to the bewildering history of conflicting bodies of knowledge and pathogenesis. In 1833, it was referred to as Velpeau disease, named after Alfred-Armand-Louis-Marie Velpeau, a French anatomist and surgeon, who was the first person who noted an unusual inflammatory process of the sebaceous follicle. He first described a ‘phlegmon tubériforme’ (tuberiform phlegmon) of the axilla, characterized by superficial abscess formation and often resulting in pain and suppuration. Velpeau then discovered painful induration and tumours, as a similar clinic aspect of HS, naming it ‘phlegmon érysipélateux’ (erysipelas phlegmon). In 1864, Verneuil renamed the disease to hidrosadénite phlegmoneuse, the French term for ‘hidradenitis suppurativa’, and defines it as a condition caused by inflammation of the sweat glands (hidradenitis) with pus collection (suppurativa). Later, Aristide Auguste Stanislas Verneuil, a French surgeon with special interest in skin and sudoral (sweat gland) tumours, found Velpeau’s discovery. He conducted the first clinical studies regarding this inflammatory condition from 1854 to 1865 and recognized that it was a disorder of sweat glands, earning it the name of Verneuil disease. In 1891, ‘acnitis’ and ‘folliclis’ were new terms introduced to describe HS as part of folliculitis, by French physician Barthélémy. However, these were soon rejected by French dermatologist William Auguste Dubreuilh, in favour of ‘hydrosadenitis’. In 1956, Pillsbury came up with the term ‘follicular occlusion triad’ as a group disorder consisting of HS, acne conglobata and dissecting cellulitis of the scalp. This decision was made on common features of follicular hyperkeratinization, with keratin retention complicated with bacterial infection in these conditions. Nineteen years later in 1975, Plewig and Kligman added pilonidal sinus to the follicular occlusion triad and introduced the new term ‘acne tetrad’. Histopathologically, all four entities are identical, with evidence of follicular occlusion causing inflammation of sweat glands. Given the inverse localizations of HS compared with the acne tetrad, Plewig suggested the term ‘acne inversa’ instead in 1989. In 2005, American dermatologists Sellheyer and Krahl observed histopathological evidence of hair follicle occlusion and noted clinical and therapeutic similarities to acne. They insisted on abandoning the name ‘HS’, replacing it with ‘acne inversa’. However, adversaries of the name ‘acne inversa’ contended that more research should be conducted, as histology alone does not define dermatology. HS is currently the recognized name of this disease, as agreement on its terminology has yet to be reached, despite centuries of research.