Recurrent inverse necrotizing infundibular crystalline folliculitis.

Necrotizing infundibular crystalline folliculitis (NICF) is a rare type of necrotizing folliculitis. The disease typically manifests as folliculocentric papules arising in a seborrheic distribution. Only 23 cases exist in the literature. Most reported cases have arisen spontaneously, but a small number of drug-induced cases in the setting of epidermal-derived growth factor, vascular endothelial-derived growth factor, or PD-1 inhibitor therapy have been reported. Colonization by bacteria and/or yeast occurs frequently. The etiology remains unknown, but some suggest a complex interplay with an aberrant microbiome, sebaceous gland dysfunction, and perturbed EGFR signaling in follicular infundibula. Histopathologic findings include rupture of follicular epithelium, neutrophilic inflammation, and nodular cup-shaped crystal deposits. We present a case of spontaneous, recurrent NICF in an inverse pattern in the inguinal region.

Recurrent papulonodular herpes zoster, with syringitis, folliculitis, and vasculitis as clues to the diagnosis.

Herpes zoster (HZ) may have atypical clinical presentations, particularly in immunosuppressed patients. Nodular HZ is an extremely rare condition. We report the first case of recurrent papulonodular HZ in an adult patient with inflammatory bowel disease (IBD) receiving biologic treatment. More interestingly, there was no epidermal involvement on histopathological examination, but the involvement of the adnexa and blood vessels was a clue to the diagnosis in view of the clinical context. We wish to raise awareness of this rare manifestation of HZ for early diagnosis and proper treatment.

Clinical Characterization and Treatment Response of Folliculitis Decalvans Lichen Planopilaris Phenotypic Spectrum: A Unicentre Retrospective Series of 31 Patients.

Folliculitis decalvans and lichen planopilaris phenotypic spectrum has been described as a form of cicatricial alopecia. The aim of this study is to describe the clinical and trichoscopic features and therapeutic management of this condition in a series of patients. A retrospective observational unicentre study was designed including patients with folliculitis decalvans and lichen planopilaris phenotypic spectrum confirmed with biopsy. A total of 31 patients (20 females) were included. The most common presentation was an isolated plaque of alopecia (61.3%) in the vertex. Trichoscopy revealed hair tufting with perifollicular white scaling in all cases. The duration of the condition was the only factor associated with large plaques (grade III) of alopecia (p = 0.026). The mean time to transition from the classic presentation of folliculitis decalvans to folliculitis decalvans and lichen planopilaris phenotypic spectrum was 5.2 years. The most frequently used treatments were topical steroids (80.6%), intralesional steroids (64.5%) and topical antibiotics (32.3%). Nine clinical relapses were detected after a mean time of 18 months (range 12-23 months). Folliculitis decalvans and lichen planopilaris phenotypic spectrum is an infrequent, but probably underdiagnosed, cicatricial alopecia. Treatment with anti-inflammatory drugs used for lichen planopilaris may be an adequate approach.

Cold atmospheric plasma therapy for Malassezia folliculitis: Laboratory investigations and a randomized clinical trial.

BACKGROUND: Current treatment options for Malassezia folliculitis (MF) are limited. Recent research has demonstrated the inhibitory effect of cold atmospheric plasma (CAP) on the growth of Malassezia pachydermatis in vitro, suggesting CAP as a potential therapeutic approach for managing MF. OBJECTIVES: The objective of our study is to assess the in vitro antifungal susceptibility of Malassezia yeasts to CAP. Additionally, we aim to evaluate the efficacy and tolerability of CAP in treating patients with MF. METHODS: We initially studied the antifungal effect of CAP on planktonic and biofilm forms of Malassezia yeasts, using well-established techniques such as zone of inhibition, transmission electron microscopy, colony count assay and 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide salt assay. Subsequently, a randomized (1:1 ratio), active comparator-controlled, observer-blind study was conducted comparing daily CAP therapy versus itraconazole 200 mg/day for 2 weeks in 50 patients with MF. Efficacy outcomes were measured by success rate, negative microscopy rate and changes in Dermatology Life Quality Index (DLQI) and Global Aesthetic Improvement Scale (GAIS) scores. Safety was assessed by monitoring adverse events (AEs) and local tolerability. RESULTS: In laboratory investigations, CAP time-dependently inhibited the growth of Malassezia yeasts in both planktonic and biofilm forms. Forty-nine patients completed the clinical study. At week 2, success was achieved by 40.0% of subjects in the CAP group versus 58.3% in the itraconazole group (p = 0.199). The negative direct microscopy rates of follicular samples were 56.0% in the CAP group versus 66.7% in the itraconazole group (p = 0.444). No significant differences were found in the proportion of subjects achieving DLQI scores of 0/1 (p = 0.456) or in the GAIS responder rates (p = 0.588) between the two groups. Three patients in the CAP group and one patient in the itraconazole group reported mild AEs. CONCLUSION: CAP demonstrated significant antifungal activity against Malassezia yeasts in vitro and exhibited comparable efficacy to itraconazole in treating MF patients. Without the associated adverse effects of oral antifungal drugs, CAP can be considered a promising and safe treatment modality for MF.

NLRP3 regulates CIITA/MHC II axis and interferon-γ-inducible chemokines in Malassezia globosa-infected keratinocytes.

CIITA, a member of NOD-like receptor (NLR) family, is the major MHC II trans-activator and mediator of Th1 immunity, but its function and interaction with NLRP3 have been little studied. We found activation of NLRP3 inflammasome, increased expression of CIITA, CBP, pSTAT1, STAT1, MHC II, IFN-γ and IFN-γ-inducible chemokines (CCL1 and CXCL8), and colocalisation of NLRP3 with CIITA in Malassezia folliculitis lesions, Malassezia globosa-infected HaCaT cells and mouse skin. CoIP with anti-CIITA or anti-NLRP3 antibody pulled down NLRP3 or both CIITA and ASC. NLRP3 silencing or knockout caused CIITA downexpression and their colocalisation disappearance in HaCaT cells and mouse skin of Nlrp3-/- mice, while CIITA knockdown had no effect on NLRP3, ASC, IL-1ß and IL-18 expression. NLRP3 inflammasome inhibitors and knockdown significantly suppressed IFN-γ, CCL1, CXCL8 and CXCL10 levels in M. globosa-infected HaCaT cells. CCL1 and CXCL8 expression was elevated in Malassezia folliculitis lesions and reduced in Nlrp3-/- mice. These results demonstrate that M. globosa can activate NLRP3 inflammasome, CIITA/MHC II signalling and IFN-γ-inducible chemokines in human keratinocytes and mouse skin. NLRP3 may regulate CIITA by their binding and trigger Th1 immunity by secreting CCL1 and CXCL8/IL-8, contributing to the pathogenesis of Malassezia-associated skin diseases.

Proliferative, lymphocytic, infundibular mural folliculitis and dermatitis with prominent follicular apoptosis and parakeratotic casts in a Labrador retriever: Clinical, histopathological and dermoscopic features and co-morbidities.

Proliferative, lymphocytic, infundibular mural folliculitis and dermatitis have been reported in six female Labrador retrievers from North America. This is the first report of the disease outside North America, describing the clinical and histopathological diagnosis and dermoscopic aspect of the verrucous plaques, treatment and co-morbidities in a female Labrador retriever dog.

La folliculite et la dermatite murale infundibulaire proliférative, lymphocytaire ont été rapportées chez six Labrador retrievers femelles d'Amérique du Nord. Il s'agit du premier rapport de cette affection en dehors de l'Amérique du Nord, décrivant le diagnostic clinique et histopathologique, l'aspect dermatoscopique des plaques verruqueuses, le traitement et les comorbidités chez une femelle Labrador retriever.

A foliculite e dermatite mural linfocítica infundibular proliferativa tem sido relatada em seis cadelas Labrador retriever da América do Norte. Este é o primeiro relato da doença fora da América do Norte, descrevendo o diagnóstico clínico e histopatológico e o aspecto dermoscópico de placas verrucosas, tratamento de comorbidades em uma cadela Labrador retriever.

Se ha publicado la descripción de una foliculitis y dermatitis mural infundibular, linfocítica y proliferativa en seis hembras de Labrador Retriever de América del Norte. Este es el primer informe de la enfermedad fuera de América del Norte, que describe el diagnóstico clínico e histopatológico y el aspecto dermatoscópico de las placas verrugosas, el tratamiento y las comorbilidades en una perra Labrador Retriever.

Confocal microscopy and optical coherence tomography of inflammatory skin diseases in hairs and pilosebaceous units: A systematic review.

Common skin disorders such as acne vulgaris, rosacea and folliculitis are bothersome prevalent inflammatory diseases of hair follicles that can easily be investigated bedside using optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) with micrometre resolution, opening a novel era for high-resolution hair follicle diagnostics and quantitative treatment evaluation. EMBASE, PubMed and Web of Science were searched until 5 January 2023 to identify all studies imaging hair follicle characteristics by RCM and OCT for diagnosis and monitoring of treatment in hair follicle-based skin disorders. This study followed PRISMA guidelines. After inclusion of articles, methodological quality was assessed using the QUADAS-2 critical appraisal checklist. Thirty-nine in vivo studies (33 RCM and 12 OCT studies) were included. The studies focused on acne vulgaris, rosacea, alopecia areata, hidradenitis suppurativa, folliculitis, folliculitis decalvans, lichen planopilaris, discoid lupus erythemasus, frontal fibrosing alopecia and keratosis pilaris. Inter- and perifollicular morphology including number of demodex mites, hyperkeratinization, inflammation and vascular morphology could be assessed by RCM and OCT in all included skin disorders. Methodological study quality was low, and interstudy outcome variability was high. Quality assessment showed high or unclear risk of bias in 36 studies. Both RCM and OCT visualize quantitative features as size, shape, content and abnormalities of hair follicles, and have potential to support clinical diagnosis and evaluate treatment effects. However, larger studies with better methodological quality are needed to implement RCM and OCT directly into clinical practice.

EGFR inhibitor-induced folliculitis decalvans: a case series and management guidelines.

Epidermal growth factor receptor (EGFR) is one of therapeutic targets in oncology for solid tumors originating from epithelial tissue, such as non-small-cell lung carcinoma (NSCLC) and breast cancer. EGFR inhibitors used in cancer treatment may cause a broad spectrum of dose-dependent cutaneous adverse events, including acneiform papulopustular rash, nail and hair disturbances, xerosis, and mucositis. The pathogenesis of the EGFR inhibitor-induced adverse reactions originates from disturbances in keratinocyte differentiation, cytokine secretion, and neutrophil chemotaxis. One of the rare, yet distressing adverse events may be folliculitis decalvans, a progressive neutrophil-driven scarring alopecia with hair tufts formation resembling doll's hair. Early diagnosis and introduction of treatment are crucial for disease prognosis since a long course of the disease leads to decreased quality of life. Here, we review the literature cases of EGFR inhibitor-induced folliculitis decalvans and provide guidance on management and prevention of this condition in oncologic patients. Furthermore, we report the first afatinib-associated folliculitis decalvans in three female patients with NSCLC.

Folliculitis Decalvans Has a Heterogeneous Microbiological Signature and Impaired Immunological Response.

BACKGROUND: Folliculitis decalvans (FD) is a rare primary neutrophilic scarring alopecia whose etiology has not been completely elucidated yet. OBJECTIVE: The aim of the study was to determine if the follicular microbiota residing in FD-affected hair follicles had a distinct microbiological signature and if an aberrant immune response was present in the pathogenesis of FD. METHODS: We conducted a cross-sectional study of 10 patients affected by FD. Trichoscopy-guided follicular biopsies were taken from affected and healthy scalp to identify the follicular microbiome using next-generation sequencing. We searched for microbiological biomarkers of FD-affected follicles using the linear discriminant analysis (LDA) effect size (LEfSe) tool. Additionally, peripheral blood mononuclear cells were obtained, and their cytokine production was quantified after incubation with pathogen-associated molecular patterns isolated from patients' biopsies and compared with healthy controls. RESULTS: ß-diversity analysis showed statistically significant differences regarding bacteria comparing follicular microbiota of healthy and FD-affected hairs. Ruminococcaceae, Agathobacter sp., Tyzzerella sp., and Bacteriodales vadin HA21 family were good predictors of disease status. IL-10, TNF-α, and IL-6 levels were significantly decreased in patients after incubation with various strains of bacteria compared with controls. CONCLUSION: FD hair follicles have a specific heterogenous follicular bacterial microbiota signature. Additionally, these patients seem to have an impaired immunological response.

Efficacy and Safety of Tumour Necrosis Factor-α Antagonists for Folliculitis Decalvans: A Retrospective Case-series Pilot Study.

Folliculitis decalvans is a chronic inflammatory skin disease leading to scarring alopecia. Management of this disabling disease is difficult and no treatment is currently approved. Current knowledge regarding the pathogenesis of folliculitis decalvans suggests the benefit of using anti-tumour necrosis factor-α. This pilot study aimed to evaluate the clinical efficacy of anti-tumour necrosis factor-α for management of folliculitis decalvans. A single-centre retrospective pilot study included patients with refractory folliculitis decalvans treated by tumour necrosis factor-α inhibitors. An Investigator's Global Assessment (IGA) score was designed and validated to assess the efficacy of the therapy. Response to treatment was considered good to excellent when an IGA ≤ 2 was obtained at month 12. Eleven patients were included, with a mean time from diagnosis of folliculitis decalvans to the introduction of infliximab (n = 9) or adalimumab (n = 2) of 8.55 ± 1.26 years. Nine patients had failed on at least 2 lines of systemic therapies before starting anti-tumour necrosis factor-α. The median IGA score at baseline was 3. At the end of follow-up, 5 patients were considered responders. Overall, the safety profile of anti-tumour necrosis factor-α was good. The results suggest that the clinical benefit of anti-tumour necrosis factor-α is obtained after at least 6 months of treatment. However, further prospective studies are needed to confirm these results.

Granulomatous mural folliculitis in 16 domestic goats: Infection with malignant catarrhal fever viruses and colocalization with ovine herpesvirus-2 using in situ hybridization.

Granulomatous mural folliculitis (GMF) is an uncommon reaction pattern occasionally observed in nonadapted ruminant hosts infected with malignant catarrhal fever viruses. This report characterizes GMF and concurrent cutaneous lesions in 16 goats with crusting dermatitis using histochemistry including hematoxylin and eosin, periodic acid-Schiff, and Grocott's methenamine silver, and immunohistochemistry for CD3, CD20, ionized calcium binding adaptor molecule 1, and cytokeratin AE1/3. Infiltrates in all 16 GMF cases consisted of macrophages and fewer T lymphocytes, and variably included eosinophils, multinucleated histiocytic giant cells, and/or neutrophils. Formalin-fixed paraffin-embedded skin and fresh skin samples from caprine GMF cases were tested using pan-herpesvirus nested conventional polymerase chain reaction (PCR) and partial sequencing, ovine herpesvirus-2 (OvHV-2) real-time PCR, and OvHV-2 colorimetric in situ hybridization (ISH). Five of 16 goats with GMF (31%) were PCR positive for malignant catarrhal fever viruses, including caprine herpesvirus 3 in 1 goat and OvHV-2 in 4 goats. Three goats also had positive intranuclear OvHV-2 hybridization signal in follicular keratinocytes, among other cell types, localized to areas of GMF. Herpesviruses were not detected in the formalin-fixed paraffin-embedded skin of 9 goats without GMF. This case series describes relatively frequent detections of malignant catarrhal fever viruses in the skin of goats with GMF, including the first report of caprine herpesvirus 3, and localizes OvHV-2 infected follicular keratinocytes within areas of GMF.

Widespread, symmetric, noninflammatory alopecia associated with follicular dysplasia in the American red squirrel (Tamiasciurus hudsonicus).

This report describes a unique pattern of alopecia in 8 American red squirrels (Tamiasciurus hudsonicus) from 2013 to 2021. All animals were juveniles; 6 were female and 2 were male. Seven presented between September and November, and one presented in April. All squirrels had widespread, bilaterally symmetric, noninflammatory, well-demarcated alopecia involving the entire trunk and legs and normal hair on their muzzle and dorsal surfaces of their paws. Six months later, a normal hair coat had grown on 2 of the animals, which were littermates. Hair fully grew 2 months later in another animal. Histopathology of the alopecic skin was performed in 7 of 8 animals. The following changes were noted: bent and coiled hairs, perforating folliculitis, melanin clumping, and distortion of hair shafts. Based on features of follicular dysplasia and apparent seasonality, this condition has some similarities to canine seasonal flank alopecia. A genetic etiology is suspected.

Histopathologic Spectrum of Alopecias Seen in a Jamaican Setting.

ABSTRACT: Alopecia is common in Jamaican, primarily Afro-Caribbean patients. We performed a retrospective review examining the histopathologic alopecia diagnoses over ∼5 years. Requisition forms and pathology reports were assessed. Demographic/clinical/technical/diagnostic and pathologic findings of chronicity/severity data were recorded. Three hundred thirty-eight biopsies were included. The majority were 4 mm punches, grossed horizontally. The F:M ratio was 4.8:1, mean age = 42.7 years, and mean duration of alopecia = 5.1 years. Cicatricial alopecias (CAs) predominated over non-CAs (NCAs). The top 10 diagnoses were central centrifugal CA (21.9%), folliculitis decalvans (10.9%), multifactorial alopecias (10.1%), pattern hair loss (8%), lichen planopilaris (7.1%), alopecia areata (6.2%), discoid lupus erythematosus (6.2%), nonclassifiable lymphocytic scarring alopecias (5.6%), frontal fibrosing alopecia (5.3%), and nonspecific NCAs (5%). This contrasted with other richly pigmented populations where discoid lupus erythematosus predominates. Other interesting findings included relatively frequent folliculitis decalvans and lichen planus pigmentosus in 40.9% of frontal fibrosing alopecia cases. Scarring/nonscarring clinicopathologic congruence occurred in 83.4%.Regarding histopathologic features of severity/chronicity, CAs had markedly decreased hair counts. Perifollicular fibrosis affecting retained hairs occurred in 75% of CAs, moderate to severe in >50% of these. Approximately 50% of NCA samples demonstrated advanced miniaturization (T:V ratio <2:1). In our study, relatively young women with chronic hair loss and CA are most frequently biopsied. Central centrifugal CA is the most common diagnosis. Local features of chronic/severe disease are seen microscopically. Clinical impression of scarring/nonscarring correlates well with histopathology.

Position statement: Recommendations on the diagnosis and treatment of Malassezia folliculitis.

Malassezia is a lipophilic yeast that is a part of the human mycobiome. Malassezia folliculitis appears when the benign colonization of the hair follicles, by the Malassezia yeasts, becomes symptomatic with pruritic papules and pustules. Although Malassezia folliculitis is common in hospital departments, diagnosing and treating it varies among dermatologists and countries. The European Academy of Dermatology and Venereology Mycology Task Force Malassezia folliculitis working group has, therefore, sought to develop these recommendations for the diagnosis and management of Malassezia folliculitis. Recommendations comprise methods for diagnosing Malassezia folliculitis, required positive findings before starting therapies and specific treatment algorithms for individuals who are immunocompetent, immunocompromised or who have compromised liver function. In conclusion, this study provides a clinical strategy for diagnosing and managing Malassezia folliculitis.

Changing spectrum of hair and scalp disorders over the last decade in a tertiary medical centre.

BACKGROUND: Hair- and scalp-related disorders (HSRDs) encompass a wide range of conditions that affect people of all ages. OBJECTIVE: To evaluate the workload and trends in HSRDs at an outpatient dermatological clinic in a tertiary medical centre over a 10-year period. METHODS: Medical records for HSRD visits to the outpatient dermatology clinic at the Sheba Medical Center, an Israeli tertiary care center, were reviewed between 1 January, 2010 and 31 December, 2020. RESULTS: There were 10,396 HSRD visits with a new-to-follow-up visit ratio of 1:1.9. The annual number of HSRD visits, as well as their proportion out of all dermatological outpatient visits, have increased from 295 (1.24%) in 2010 to 1726 (9.44%) in 2020. The patients' mean age was 35.3 years (women 39.5 years, men 28.8 years), age range 1-87 years. Over the decade, there was a growing predominance of women with an average female-to-male ratio of 2:1. The winter season accounted for 28.7% of annual visits, followed by the autumn (25.6%), summer (24.3%) and spring (21.4%). The most prevalent HSRDs included androgenetic alopecia (30.6%), alopecia areata (19.3%), telogen effluvium (15.4%), non-scarring folliculitis (15.4%), seborrheic dermatitis (14.9%), lichen planopilaris (7.1%) and folliculitis decalvans (6.6%). Androgenetic alopecia demonstrated the highest increase over the decade examined (from 17% to 32%). CONCLUSION: HSRDs account for a significant percentage of visits at a tertiary dermatology outpatient clinic. The number of HSRD visits has increased annually over the past decade. The recent advancement in diagnosis and treatment may account, at least in part, for the growing burden of HSRDs within dermatological ambulatory care.

Eosinophilic pustule smear in the diagnosis of pediatric post-transplant eosinophilic folliculitis.

Hematologic-associated eosinophilic pustular folliculitis is a subtype of eosinophilic pustular folliculitis (EPF) which develops in patients with underlying hematological malignancies after treatment with chemotherapy, bone marrow transplant (BMT), or stem cell transplant (SCT). Few cases of hematological-associated EPF have been reported in pediatric patients. Skin biopsy is considered the gold standard for diagnosis. We describe a case in which Wright staining of a pustule smear for eosinophils provided data to rapidly support a clinical diagnosis of hematologic-associated EPF.

Turpentine Ointment for the Treatment of Folliculitis: An Open, Prospective, Randomized, Placebo- and Comparator-Controlled Multicenter Trial.

INTRODUCTION: Folliculitis is a painful infection and inflammation of the hair follicles, mostly caused by bacterial, fungal, or, more rarely, viral infections. Turpentine derivatives have been used traditionally to treat various skin infections and could thus also be effective in treating folliculitis. We carried out an open, prospective, randomized, placebo- and comparator-controlled multicenter trial to evaluate the efficacy and safety of an ointment containing pine turpentine oil, larch turpentine, and eucalyptus oil in the treatment of acute folliculitis. METHODS: Seventy outpatients with acute folliculitis were treated with the turpentine ointment, a comparator (povidone iodine solution), or a placebo (Vaseline) for 7 days. Photographs of the affected skin areas were taken by the physicians at four visits and by the patients on a daily basis. Photographs were evaluated by blinded observers. Primary efficacy endpoint was the change in total hair follicle lesion counts. Secondary endpoints included the evolution of the lesion counts in the course of the study, responder rate (improvement of follicle lesions by at least one count), and the patient's global assessment. Safety endpoints were the tolerability of the treatments and adverse event recording. RESULTS: A decrease of follicle lesions counts was detected for both active treatments but not for placebo, but the differences among groups were not statistically significant. As for the secondary endpoints, the ointment showed statistically significant superiority over placebo for the evolution of the lesions during the course of the study (p = 0.017), the responder rate (p = 0.032), and the subjective efficacy assessment by patients (p = 0.029). All treatments were equally well tolerated, with a similar number of treatment-emergent adverse events. CONCLUSION: The turpentine ointment is an effective and safe option for the treatment of folliculitis.

Alopecia in Patients with Collagen VI-Related Myopathies: A Novel/Unrecognized Scalp Phenotype.

Collagen VI-related myopathies are characterized by severe muscle involvement and skin involvement (keratosis pilaris and impaired healing with the development of abnormal scars, especially keloids). Scalp involvement and hair loss have not been reported among cutaneous changes associated with collagen VI mutations. The aim of this study is to describe the clinical, trichoscopic, and histological findings of the scalp changes in patients affected by COL VI mutations and to estimate their prevalence. Patients with Ullrich congenital muscular dystrophy were enrolled and underwent clinical and trichoscopic examinations and a scalp biopsy for histopathology. Five patients were enrolled, and all complained of hair loss and scalp itching. One patient showed yellow interfollicular scales with erythema and dilated, branched vessels, and the histological findings were suggestive of scalp psoriasis. Two patients presented with scarring alopecia patches on the vertex area, and they were histologically diagnosed with folliculitis decalvans. The last two patients presented with scaling and hair thinning, but they were both diagnosed with folliculitis and perifolliculitis. Ten more patients answered to a "scalp involvement questionnaire", and six of them confirmed to have or have had scalp disorders and/or itching. Scalp involvement can be associated with COL VI mutations and should be investigated.

Diagnostic delay, comorbid hidradenitis suppurativa and the prognostic value of bacterial culture in folliculitis decalvans: A cohort study.

BACKGROUND: Folliculitis decalvans (FD) is a type of primary neutrophilic cicatricial alopecia often leading to irreversible hair loss. Data on its epidemiology, clinical features, outcomes, and prognostic factors are limited. OBJECTIVE: To evaluate a cohort of patients with FD and identify characteristics of severe disease and prognostic factors which impede remission. PATIENTS AND METHODS: This retrospective cohort study included 192 patients diagnosed with FD and followed for at least six months at a tertiary center between 2010 and 2020. RESULTS: There was a diagnostic delay averaging 22.2 (± 29.7) months. Comorbid follicular occlusion disorders were common. Bacterial cultures were positive in 45.6% of the cases, with Staphylococcus (S.) aureus being the most common pathogen. Severe disease was associated with comorbid hidradenitis suppurativa and a positive bacterial culture, particularly S. aureus. 50.7% of patients experienced complete remission: 32% within the first six months of treatment and 18.7% later during follow-up. Relapses were frequent. Negative prognostic factors for achieving remission included younger age and a positive bacterial culture. CONCLUSIONS: There is a need for the education of dermatologists to reduce the diagnostic delay. Screening FD patients for comorbid hidradenitis suppurativa and obtaining bacterial cultures is important for treatment planning.

Folliculitis decalvans and dystrophic epidermolysis bullosa: a significant association.

This work reports 30 cases of folliculitis decalvans (FD) in patients with dystrophic epidermolysis bullosa (DEB) among a cohort of 125 DEB patients seen between 2010 and 2021 in 2 French expert centers for the management of inherited epidermolysis bullosa. Such an association between two rare diseases cannot be fortuitous and implies a physiopathological link that we discuss in this paper. This association is a new significant fact to add to the reflexion on FD causes, suggesting that skin abnormality of DEB could act as a factor of a specific skin barrier alteration which could favor FD. Scarring alopecia with tufted folliculitis and pustules on inflamed skin at the vertex of a woman with dominant dystrophic epidermolysis bullosa.