Scalp microbiome: a guide to better understanding scalp diseases and treatments.

The scalp microbiome represents an array of microorganisms important in maintaining scalp homeostasis and mediating inflammation. Scalp microbial dysregulation has been implicated in dermatologic conditions including alopecia areata (AA), dandruff/seborrheic dermatitis (D/SD), scalp psoriasis (SP) and folliculitis decalvans (FD). Understanding the impact of scalp microbial dysbiosis gives insight on disease pathophysiology and guides therapeutic decision making. Herein we review the scalp microbiome and its functional role in scalp conditions by analysis of metagenomic medical literature in alopecia, D/SD, SP, and other dermatologic disease.Increased abundance of Malassezia, Staphylococcus, and Brevibacterium was associated with SD compared to healthy controls. A higher proportion of Corynebacterium, actinobacteria, and firmicutes are present in AA patients, and lower proportions of Staphylococcus caprae are associated with worse clinical outcomes. Decreased prevalence of actinobacteria and Propionibacterium and increased firmicutes, staphylococcus, and streptococcus are associated with scalp psoriasis. Studies of central centrifugal cicatricial alopecia (CCCA) suggest scalp microbial composition contributes to CCCA's pro-inflammatory status. The most common organisms associated with FD include methicillin-resistant S. aureus and S. lugdunensis. Antifungals have been a mainstay treatment for these diseases, while other alternatives including coconut oils and shampoos with heat-killed probiotics have shown considerable potential efficacy by replenishing the scalp microbiome.

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.

Common Skin Conditions in Children and Adolescents: Bacterial Infections.

Bacterial skin infections represent a significant health care burden. Cellulitis and erysipelas are rapidly spreading, painful, superficial skin infections, usually caused by streptococci or Staphylococcus aureus. Folliculitis is an infection of hair follicles mostly caused by S aureus. Simple folliculitis typically is self-limited. Topical benzoyl peroxide is a first-line nonantibiotic treatment. Mupirocin and clindamycin are topical antibiotic options. For treatment-resistant cases, oral cephalexin or dicloxacillin is an appropriate option. Impetigo is a common, self-limited infection in children. Bullous impetigo is caused by S aureus, and nonbullous impetigo is caused by beta-hemolytic streptococci, S aureus, or both. In most cases, topical mupirocin or retapamulin (Altabax) is effective. Oral antibiotics should be considered for household outbreaks or patients with multiple lesions. Abscesses are red, painful collections of purulence in the dermis and deeper tissues caused by S aureus or polymicrobial infections. Furuncles are abscesses of a hair follicle, whereas carbuncles involve several hair follicles. In recurrent cases of these lesions, culture of the exudate is recommended. Abscess, furuncle, and carbuncle management consists of incision and drainage. Oral antibiotics are not necessary in most cases but should be prescribed for patients with severe immunocompromise or systemic signs of infection. In bacterial skin infections, methicillin-resistant S aureus coverage should be considered for patients with infections that have not improved with treatment.

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.

Clinico-laboratory findings of Malassezia folliculitis in Indonesia: A multicentre study.

BACKGROUND: Malassezia folliculitis (MF) is a humid-favoured fungal skin disease caused by Malassezia species. Inaccurate treatments, changes in skin flora and disease exacerbation are often occurred due to oversights in the diagnosis. Several diagnostic methods are established for MF. OBJECTIVE: To identify clinico-laboratory findings of Malassezia folliculitis in Indonesia. METHODS: The study was conducted from January 2014 to December 2018 in seven referral teaching hospitals. Medical records of MF-diagnosed patients were obtained and analysed using the binomial test, chi-square test and Cohen's Kappa coefficient in SPSS 26.0. RESULTS: A total of 353 cases of MF were identified in seven referral teaching hospitals in Indonesia, 66.3% of which were males and 33.7% were females, dominated by the 17-25 years old group (44.5%). Itchy sensation (83.9%) was a major subjective complaint. Lesions were majorly found on the trunk-chest, back and shoulder (68.3%), while the clinical manifestation are mostly follicular papule-pustular lesions (62.1%). Patients were 87.4% positive by KOH examination (modified Jacinto Jamora's criteria) and 69.1% positive by Wood's lamp. Generally, sex, age, subjective complaint, lesion location, clinical manifestation and both examinations were statistically significant (p < .001). A significant relationship between all the clinical criteria of the patients in the KOH especially the clinical manifestation was significantly related to Wood's lamp. The Cohen's Kappa assessment suggested that there was an agreement between KOH and Wood's lamp (κ = -0.272, p < .001). CONCLUSION: The clinical symptoms of Malassezia folliculitis are dominated by pruritus, papulopustular follicular lesions on the trunk and the presence of spore load.

Common condition with uncommon cause: fungal folliculitis in immunosuppressed patient with Blau syndrome.

We present a case of a patient with a history of Blau syndrome, who presented with acute onset of widespread florid painful folliculitis rash, which was resistant to the treatment with multiple courses of antibiotics in the community. Despite of the negative skin swab and negative periodic acid-schiff (PAS)stain on the skin biopsy, clinical diagnosis was fungal folliculitis and patient responded well to the course of itraconazole.

Hostage to history - questioning the duration of systemic antimicrobial therapy for the treatment of canine superficial bacterial folliculitis.

Current guidelines for the use of systemic antimicrobials for the treatment of superficial bacterial folliculitis in dogs include the recommendation that the disease be treated for a minimum of 3 weeks and for at least 1 week beyond clinical resolution. With increasing antimicrobial resistance being noted for bacteria involved in this condition, as well as the increased use of evidence-based medicine, this dogma needs to be reevaluated.

Skin manifestations of Pseudomonas aeruginosa infections.

PURPOSE OF REVIEW: Pseudomonas aeruginosa is an opportunistic pathogen with considerable morbidity and mortality, particularly in vulnerable hosts. Skin manifestations are common, either representing local inoculation or secondary skin seeding following bloodstream infections. As patients with various predisposing conditions are expanding, we sought to review the most recent published evidence regarding epidemiology, risk factors and diagnosis of skin manifestations of P. aeruginosa. RECENT FINDINGS: New data exist on epidemiology and diagnosis of skin infections; systemic infections are impacted by multidrug-resistance issues and host immune status. SUMMARY: Green nail syndrome, toe web infection, hot tub folliculitis, hot hand-foot infection and external otitis are the most common infections originating from the skin per se. Local treatments are the cornerstone and prognosis is favorable in immunocompetent hosts. Ecthyma gangrenosum and P. aeruginosa subcutaneous nodules are usually associated with bloodstream infections and occur primarily in immunocompromised hosts. Necrotizing skin and soft tissue infections occur in diabetic, alcoholic and immunocompromised patients; management requires a multidisciplinary team with surgical approach. Burn wound infections may also be challenging, requiring a specialized team. In all the four latter types of P. aeruginosa skin infections portending significant morbidity and mortality, systemic antibiotics are an integral part of the treatment.

Aseptic Folliculitis in Freshwater and Marine Fishermen.

Folliculitis is a common skin disease, usually benign, which causes inflammation and eventual infections of hair follicles. They may have an infectious etiology, mainly due to the bacteria Staphylococcus aureus; it also occurs due to localized irritation, such as in areas of skin friction and for long periods of immersion in water, as in athletes and workers who are continuously exposed to the aquatic environment. Herein, we report on two fishermen, from fluvial and maritime environments, who presented with chronic aseptic folliculitis associated with daily immersion of their lower extremities while exercising the profession and that regressed when there was a decrease in their contact with water.

Gram-negative infections in patients with folliculitis decalvans: a subset of patients requiring alternative treatment.

Background Folliculitis decalvans is a neutrophilic cicatricial alopecia whose etiology remains unknown. It is frequently associated with staphylococcal infections. We aimed to determine the rate of gram-negative infections in patients with folliculitis decalvans. Methods A retrospective chart review was performed of patients with biopsy-proven folliculitis decalvans seen at a tertiary hair referral center. The results of bacterial cultures were evaluated. Subjects were determined to have no infection, gram-positive infections, gram-negative infections, or mixed infections. Results Thirty-nine subjects were included in the study. Ninety-three cultures were performed. The majority of cultures were positive for staphylococci. Eleven patients (28%) had gram-negative infections of the scalp. Gram-negative infections comprised one-third of all cultures (33%). Conclusion We present the largest cohort of folliculitis decalvans patients with gram-negative infections, suggesting the need for routine bacterial cultures in patients who are not responsive to standard anti-staphylococcal antibiotics. Awareness of the incidence of these infections may lead to better therapeutic outcomes.

Molecular epidemiology, in vitro susceptibility and exoenzyme screening of Malassezia clinical isolates.

Introduction. Malassezia folliculitis (MF) and pityriasis versicolor (PV) are common dermatoses caused by Malassezia species. Their molecular epidemiology, drug susceptibility and exoenzymes are rarely reported in China.Aim. To investigate the molecular epidemiology, drug susceptibility and enzymatic profile of Malassezia clinical isolates.Methodology. Malassezia strains were recovered from MF and PV patients and healthy subjects (HS) and identified by sequencing analysis. The minimum inhibitory concentrations (MICs) of nine antifungals (posaconazole, voriconazole, itraconazole, fluconazole, ketoconazole, miconazole, bifonazole, terbinafine and caspofungin) and tacrolimus, the interactions between three antifungals (itraconazole, ketoconazole and terbinafine) and tacrolimus, and the extracellular enzyme profile were evaluated using broth and checkerboard microdilution and the Api-Zym system, respectively.Results. Among 392 Malassezia isolates from 729 subjects (289 MF, 218 PV and 222 HS), Malassezia furfur and Malassezia globosa accounted for 67.86 and 18.88 %, respectively. M. furfur was the major species in MF and PV patients and HS. Among 60M. furfur and 50M. globosa strains, the MICs for itraconazole, posaconazole, voriconazole and ketoconazole were <1 µg ml-1. M. furfur was more susceptible to itraconazole, terbinafine and bifonazole but tolerant to miconazole compared with M. globosa (P<0.05). Synergistic effects between terbinafine and itraconazole or between tacrolimus and itraconazole, ketoconazole or terbinafine occurred in 6, 7, 6 and 9 out of 37 strains, respectively. Phosphatases, lipases and proteases were mainly secreted in 51 isolates.Conclusions. Itraconazole, posaconazole, voriconazole and ketoconazole are theagents against which there is greatest susceptibility. Synergistic effects between terbinafine and itraconazole or tacrolimas and antifungals may be irrelevant to clinical application. Overproduction of lipases could enhance the skin inhabitation of M. furfur.

Clinical features and treatment of epidermal growth factor inhibitor-related late-phase papulopustular rash.

Papulopustular rash, an acneiform rash, appears on the seborrheic region during the first to second week of treatment with an epidermal growth factor receptor inhibitor (EGFRi). The rash gradually disappears after the fourth week; however, it persists or newly develops in other regions during EGFRi treatment. Because Staphylococcus aureus is frequently isolated from late-phase papulopustular rash, we assessed the incidence of bacterial infection and treatment outcomes of patients with late-phase papulopustular rash. Sixty-four cases treated with an EGFRi over 4 weeks who presented with papulopustular rash were assessed retrospectively. The median duration of EGFR inhibitor treatment was 5 months. Grade 2 and 3 papulopustular rash was observed in 47 and eight cases, respectively. Bacterial culture was performed in 51 cases, 50 of which yielded positive results: methicillin-sensitive S. aureus in 29, methicillin-resistant S. aureus in 14, Staphylococcus species in five, Pseudomonas aeruginosa in three, and other in four cases. Of the S. aureus isolates, 42% were resistant to minocycline and 40% to levofloxacin. After treatment with topical and/or oral antibiotics without topical corticosteroids, the papulopustular rash rapidly improved by an average of 2.9 ± 3.4 weeks. However, use of a combination of antibiotics and a topical corticosteroid prolonged the recovery period to an average of 18.9 ± 11.4 weeks. In conclusion, folliculitis that develops over 4 weeks after the initiation of EGFRi treatment is typically caused by staphylococcal infection. Bacterial culture is necessary due to the high rate of antibiotic resistance. It is important to distinguish late- from early-phase papulopustular rash and to treat using different approaches.

Folliculitis decalvans is characterized by a persistent, abnormal subepidermal microbiota.

Folliculitis decalvans (FD) is a chronic inflammatory disease of unknown aetiology. Although Staphylococcus aureus, frequently found on lesional skin, is thought to play a causal role, the importance of its involvement remains controversial. To examine the role of S aureus, we compared superficial and subepidermal microbiota in 20 FD patients who had S aureus on lesional skin and in 20 healthy controls using culture techniques and genomic identification, before and after an anti-staphylococcal treatment; we also screened for S aureus virulence factors. When present on lesional skin, S aureus colonized non-lesional and subepidermal skin in 80% of cases. These data imply a break in the epidermal barrier integrity and that an abnormal non-lesional skin microbiota persists in FD. S aureus had no superantigenic toxin in 31% of cases and no toxin specificity. Clinical improvement obtained in most cases upon treatment was associated with the disappearance of S aureus in all studied areas, with an incomplete restoration of normal microbiota and a significant increase in negative bacterial samples. This persistent unbalanced, subepidermal microbiota may act as a reservoir of abnormal flora and explain the chronicity of FD, suggesting new avenues of research to restore normal microbiota.

[Acute generalized pustular bacterid followed by Sweet's syndrome and erythema nodosum]. / Pustulose aiguë généralisée post-streptococcique suivie d'un syndrome de Sweet et d'un érythème noueux.

INTRODUCTION: Streptococcal infections can cause various skin manifestations related to the direct action of the offending organism itself or to a reactional mechanism. Reactional manifestations are less well known and understood, and they include generalized acute pustulosis belonging to the spectrum of neutrophilic dermatoses. We report a case of generalized acute pustulosis followed by Sweet syndrome and erythema nodosum occurring after a streptococcal infection. PATIENTS AND METHODS: A 60-year-old woman was consulting for a diffuse pustular rash after a throat infection, with high levels of anti-streptolysin (337 U/L) and anti-streptodornase (2560 U/L). The biopsy showed folliculitis and a neutrophilic infiltrator of the dermis, and bacteriological and mycological cultures were sterile. The patient then developed papules evoking Sweet syndrome followed by nodules typical of erythema nodosum after 20 days. A favourable outcome was achieved under colchicine. DISCUSSION: Generalized acute pustulosis is a form of neutrophilic dermatosis whose mechanisms, area predilection and treatment are poorly known. The clinical presentation of this patient was initially typical and the secondary progression to lesions like those in Sweet syndrome is consistent with the pathophysiological continuity and overlap of these entities.

Folliculitis decalvans-like pustular plaques on the limbs sparing the scalp.

Folliculitis decalvans is a neutrophilic cicatricial alopecia characterised by progressive pustular folliculitis. Folliculitis decalvans is seen as a condition usually limited exclusively to the scalp and rarely affects the limbs. We present a case of a 63-year-old man with a 3-year history of progressive pustular folliculitis with inflammatory patches and central scarring alopecia on both forearms and a circumscribed patch on his right lower leg. His presentation, clinical course and isolation of Staphylococcus aureus together with the histopathological findings all supported a folliculitis decalvans-like pustular folliculitis limited to the limbs. Biopsies revealed follicular pustules, gross interfollicular fibrosis with plasma cells and concentric perifollicular fibrosis with lymphocytes, all features seen with folliculitis decalvans. The positive response to antibiotics combined with topical corticosteroids mirrored the response seen with scalp folliculitis decalvans. In contrast to the previously reported cases, the patient had no evidence of folliculitis decalvans on the scalp.