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.

Common Skin Conditions in Children and Adolescents: Atopic and Seborrheic Dermatitis.

Atopic dermatitis (AD) is a chronic, recurring, inflammatory skin condition. Xerosis, pruritus, and rash make the clinical diagnosis. Adequate skin care and regular emollient use are key in management. Topical corticosteroids are the first-line treatment for AD flare-ups. Wet wrap therapy can improve AD severity and extent. Topical calcineurin inhibitors are second-line treatments. Emollient use, topical corticosteroids and calcineurin inhibitors, and bleach baths can help prevent flare-ups. Patients with refractory AD that might require immunomodulatory treatments, such as dupilumab (Dupixent), Janus kinase inhibitors, or phototherapy, should be referred to a dermatologist. Seborrheic dermatitis (SD) is a common, chronic, relapsing, inflammatory condition that involves sebaceous skin areas. Infection with Malassezia species and the inflammatory response to it are the probable etiologies. The clinical diagnosis is made by the presence of hallmark greasy, yellow scales on the scalp or face. Infantile SD most commonly involves the scalp and forehead and typically is self-limited. In infants, application of emollients followed by hair brushing and shampooing may be effective. In infants and children, if the condition does not improve with this treatment, topical ketoconazole shampoo, gel, or lotion is safe and effective. Refractory cases of SD can be managed with topical corticosteroids and calcineurin inhibitors.

A comprehensive literature review and an international expert consensus on the management of scalp seborrheic dermatitis in adults.

Seborrheic Dermatitis of the scalp (SSD) is a chronic and relapsing inflammatory skin condition. Current SSD treatments mainly consist of topical applications of anti-fungals and anti-inflammatory agents. to review information about SSD and to provide dermatologists with practical recommendations for managing adult SSD. Material and methods: Between September and December 2023, an international group of experts in dermatology and hair and scalp disorders met to discuss published data about SD, SSD, dandruff, and management options. A total of 131 manuscripts available from PubMed were analysed, discussed and used for the present consensus. Each author was asked to complete a table listing currently used treatments to treat SSD according to the literature and to their own experience. The authors confirmed their use and regimen and commented on local treatment exceptions. They then agreed on prescription practices and proposed a general treatment approach. Currently, approved therapies to manage moderate and severe forms of SSD do not exist and there is a need for adapted and approved medications that treat efficiently and safely the disease. We propose a treatment algorithm that allows for the treatment of all severity grades of SSD. This algorithm may be completed with local treatment specifications. Despite the lack of approved therapies to manage moderate forms of SSD, a treatment algorithm is proposed and may help prescribers to manage SSD more efficiently.

A prospective, split-face, randomized controlled trial of intense pulsed light-photodynamic therapy for seborrhea.

BACKGROUND: Seborrhea poses a common cosmetic concern in adolescents and young adults, often accompanied by enlarged pores, and contributing to various skin conditions, including acne vulgaris and seborrheic dermatitis. At present, there is a lack of effective treatment for this problem, and the potential of photodynamic therapy (PDT) in reducing sebum remains inconclusive. OBJECTIVE: This exploratory, prospective, single-center, double-blinded, randomized split-face controlled trial aimed to compare the efficacy and safety of intense pulsed light-photodynamic therapy (IPL-PDT) versus IPL therapy for seborrhea. METHODS: Participants with seborrhea underwent 3 times of IPL treatment (590 nm, 15-17 J/cm2 based on patient's tolerance) for one hemifacial part and IPL-PDT treatment for the other. Follow-up assessment was conducted up to 8 weeks after the final treatment. RESULTS: Compared with single IPL treatment, IPL-PDT can significantly inhibit sebum secretion and decrease pore size. PDT group exhibited no additional damage to the skin barrier, with even lower transepidermal water loss (TEWL). Additionally, the PDT group showed superior improvement in scores of porphyrins, red areas, and ultraviolet (UV) spots. Both groups experienced only mild topical adverse effects, well tolerated by the participants. CONCLUSION: IPL-PDT is a more effective method than IPL in the treatment of seborrhea, as well as on the improvement of the skin barrier function.

Synergism Between Essential Oils and Evaluation of Their Activities with a Focus on Malassezia furfur Control.

Seborrheic dermatitis is a chronic inflammatory disease caused by Malassezia yeast species that affects the regions of the body where the sebaceous glands are present. The combined use of different essential oils (EOs) can increase their spectrum of action. Thus, the present study aimed to evaluate the action of EOs alone and in combination with each other on M. furfur, in planktonic and biofilm form, and their anti-inflammatory and mutagenic potential, in addition to the effects on the viability of cells lines. Of the 40 evaluated EOs, 22 showed activity against M. furfur at 0.5 - 2.0 mg/mL concentrations. Among the most active species, a blend of essential oils (BEOs) composed of Cymbopogon martini (Roxb.) Will. Watson (MIC = 0.5 mg/mL) and Mentha × piperita L. (MIC = 1.0 mg/mL) was selected, which showed a synergistic effect against yeast when evaluated through the checkerboard assay. The fungicidal activity was maintained by the addition of anti-inflammatory oil from Varronia curassavica Jacq. to BEOs. The BEOs also showed activity in the inhibition of biofilm formation and in the eradication of the biofilm formed by M. furfur, being superior to the action of fluconazole. Furthermore, it did not show mutagenic potential and did not interfere with the cell viability of both evaluated cell lines (HaCaT and BMDMs). TNF-α levels were reduced only by C. martini; however, this property was maintained when evaluating BEOs. BEOs had no effect on IL-8 levels. Thus, the BEOs may be indicated for alternative treatments against seborrheic dermatitis.

Diagnosis and Management of Common Inflammatory Skin Diseases in Older Adults.

Inflammatory skin conditions affect people of all ages, genders, and races. These common conditions are frequent causes of visits to the dermatologist. The geriatric population is often afflicted by these conditions because many are chronic and relapsing diseases. These inflammatory conditions include but are not limited to psoriasis, atopic dermatitis, contact dermatitis, seborrheic dermatitis, rosacea, and Grover disease. Chronic inflammatory skin conditions place a large burden on the health care system in the United States and have many associated comorbidities. This article discusses these inflammatory dermatoses that affect the geriatric population and common therapeutic options.

Evaluation of the effect of botulinum toxin injection in aggravating or improving seborrheic dermatitis symptoms: A prospective, single-arm clinical trial.

INTRODUCTION: Considering the proven therapeutic effect of botulinum toxin and the pathophysiology of seborrheic dermatitis, conflicting hypotheses have been put forward regarding the effect of injection of this toxin on the improvement or exacerbation of seborrheic dermatitis. Because of the lack of consistent studies investigating this relationship, we decided to conduct this study to investigate the effect of local botulinum toxin injection on sebum production and improvement or worsening of seborrheic dermatitis lesions. METHOD: This study was a prospective, single-arm clinical trial that involved the injection of botulinum toxin into 20 patients with complaints of skin wrinkles and simultaneous symptoms of seborrheic dermatitis. The trial was conducted at a dermatology clinic between March 2019 and March 2021. Two important characteristics of these patients were seborrheic dermatitis on the face or scalp and a referral for botulinum toxin injection to remove facial wrinkles. The Seborrheic Dermatitis Area and Severity Index (SDASI) was used to determine the severity of symptoms. RESULTS: In study of 20 patients with an average age of 40 years, despite the decrease in the average scores of all examined criteria of seborrheic dermatitis symptoms in study, 1 month after botulinum toxin injection, no significant effect of using this toxin was seen on the improvement of patients' symptoms (p value >0.05). CONCLUSION: Despite the emphasis of many studies on the effectiveness of botulinum toxin in reducing the activity of sebaceous glands, the use of botulinum toxin as a therapeutic modality for control the symptoms of seborrheic dermatitis is not suggested by this study. Conducting studies in which the location and technique of injection and the follow-up intervals of patients in them are based on the standard of other studies, are the suggestions made by comparing the results and method of the current study with other studies.

Part 1: Understanding the role of Malassezia spp. in skin disorders: Malassezia yeasts as commensal or pathogenic organisms of human and animal skin.

INTRODUCTION: Malassezia spp. are a group of lipid-dependent basidiomycetes yeasts acting as commensal organisms of the human and animal skin. However, under some not well-defined circumstances, these yeasts may switch to opportunistic pathogens triggering a number of skin disorders with different clinical presentations. The genus comprises of 18 lipid-dependent species with a variable distribution in the hosts and pathologies thus suggesting a host- and microbe-specific interactions. AREA COVERED: This review highlighted and discussed the most recent literature regarding the genus Malassezia as a commensal or pathogenic organisms highlighting Malassezia-associated skin disorders in humans and animals and their antifungal susceptibility profile. A literature search of Malassezia associated skin disorders was performed via PubMed and Google scholar (up to May 2023), using the different keywords mainly associated with Malassezia skin disorders and Malassezia antifungal resistance. EXPERT OPINION: Malassezia yeasts are part of the skin mycobiota and their life cycle is strictly associated with the environment in which they live. The biochemical, physiological, or immunological condition of the host skin selects Malassezia spp. or genotypes able to survive in a specific environment by changing their metabolisms, thus producing virulence factors or metabolites which can cause skin disorders with different clinical presentations.

Treatment with the Topical Antimicrobial Peptide Omiganan in Mild-to-Moderate Facial Seborrheic Dermatitis versus Ketoconazole and Placebo: Results of a Randomized Controlled Proof-of-Concept Trial.

Facial seborrheic dermatitis (SD) is an inflammatory skin disease characterized by erythematous and scaly lesions on the skin with high sebaceous gland activity. The yeast Malassezia is regarded as a key pathogenic driver in this disease, but increased Staphylococcus abundances and barrier dysfunction are implicated as well. Here, we evaluated the antimicrobial peptide omiganan as a treatment for SD since it has shown both antifungal and antibacterial activity. A randomized, patient- and evaluator-blinded trial was performed comparing the four-week, twice daily topical administration of omiganan 1.75%, the comparator ketoconazole 2.00%, and placebo in patients with mild-to-moderate facial SD. Safety was monitored, and efficacy was determined by clinical scoring complemented with imaging. Microbial profiling was performed, and barrier integrity was assessed by trans-epidermal water loss and ceramide lipidomics. Omiganan was safe and well tolerated but did not result in a significant clinical improvement of SD, nor did it affect other biomarkers, compared to the placebo. Ketoconazole significantly reduced the disease severity compared to the placebo, with reduced Malassezia abundances, increased microbial diversity, restored skin barrier function, and decreased short-chain ceramide Cer[NSc34]. No significant decreases in Staphylococcus abundances were observed compared to the placebo. Omiganan is well tolerated but not efficacious in the treatment of facial SD. Previously established antimicrobial and antifungal properties of omiganan could not be demonstrated. Our multimodal characterization of the response to ketoconazole has reaffirmed previous insights into its mechanism of action.

Efficacy of Roflumilast Foam, 0.3%, in Patients With Seborrheic Dermatitis: A Double-blind, Vehicle-Controlled Phase 2a Randomized Clinical Trial.

Importance: Current topical treatment options for seborrheic dermatitis are limited by efficacy and/or safety. Objective: To assess safety and efficacy of roflumilast foam, 0.3%, in adult patients with seborrheic dermatitis affecting the scalp, face, and/or trunk. Design, Setting, and Participants: This multicenter (24 sites in the US and Canada) phase 2a, parallel group, double-blind, vehicle-controlled clinical trial was conducted between November 12, 2019, and August 21, 2020. Participants were adult (aged ≥18 years) patients with a clinical diagnosis of seborrheic dermatitis for a 3-month or longer duration and Investigator Global Assessment (IGA) score of 3 or greater (at least moderate), affecting 20% or less body surface area, including scalp, face, trunk, and/or intertriginous areas. Data analysis was performed from September to October 2020. Interventions: Once-daily roflumilast foam, 0.3% (n = 154), or vehicle foam (n = 72) for 8 weeks. Main Outcomes and Measures: The main outcome was IGA success, defined as achievement of IGA score of clear or almost clear plus 2-grade improvement from baseline, at week 8. Secondary outcomes included IGA success at weeks 2 and 4; achievement of erythema score of 0 or 1 plus 2-grade improvement from baseline at weeks 2, 4, and 8; achievement of scaling score of 0 or 1 plus 2-grade improvement from baseline at weeks 2, 4, and 8; change in Worst Itch Numeric Rating Scale (WI-NRS) score from baseline; and WI-NRS success, defined as achievement of 4-point or greater WI-NRS score improvement in patients with baseline WI-NRS score of 4 or greater. Safety and tolerability were also assessed. Results: A total of 226 patients (mean [SD] age, 44.9 [16.8] years; 116 men, 110 women) were randomized to roflumilast foam (n = 154) or vehicle foam (n = 72). At week 8, 104 (73.8%) roflumilast-treated patients achieved IGA success compared with 27 (40.9%) in the vehicle group (P < .001). Roflumilast-treated patients had statistically significantly higher rates of IGA success vs vehicle at week 2, the first time point assessed. Mean (SD) reductions (improvements) on the WI-NRS at week 8 were 59.3% (52.5%) vs 36.6% (42.2%) in the roflumilast and vehicle groups, respectively (P < .001). Roflumilast was well tolerated, with the rate of adverse events similar to that of the vehicle foam. Conclusions and Relevance: The results from this phase 2a randomized clinical trial of once-daily roflumilast foam, 0.3%, demonstrated favorable efficacy, safety, and local tolerability in the treatment of erythema, scaling, and itch caused by seborrheic dermatitis, supporting further investigation as a nonsteroidal topical treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT04091646.

Maintenance effect of a once-weekly regimen of a Selenium Disulfide-based shampoo in moderate-to-severe scalp seborrheic dermatitis after initial treatment with topical corticosteroid/salicylic acid.

INTRODUCTION: Seborrheic dermatitis (SD) is a chronic, relapsing, inflammatory disorder of the head and trunk. OBJECTIVES: To explore the potential of a 1% Selenium disulphide (SeS2)-based shampoo to prevent relapses of scalp SD (SSD) following corticosteroid/salicylic acid (TCS/SA) treatment. MATERIALS & METHODS: After a 2-week treatment with TCS/SA, adult patients with moderate-to-severe SSD received either the SeS2-based shampoo or its vehicle for eight weeks in a randomized, double-blinded fashion. Visits took place at baseline, weeks 2, 6 and 10. SSD severity was assessed based on erythema, flakes and pruritus; patients assessed the severity of pruritus. Global investigator and patient satisfaction were assessed at week 10. RESULTS: Forty-eight adults were included. After four and eight weeks of post TCS/SA maintenance regimen, 8.1% and 16.7% in the SeS2, and 41.7% and 54.2% in the vehicle group relapsed, respectively. First median time-to-relapse in the vehicle group was 56 days; this was not reached for SeS2. After two weeks of TCS/SA, the prevalence of patients with no pruritus was 29.2% in the SeS2 group, and 41.7% in the vehicle group; it increased to 76.2% with SeS2 and to 57.1% with the vehicle at the end of the study. The clinical benefit of treatment with TCS/SCA was maintained in the SeS2 group only. Investigators and patients were highly satisfied with the efficacy of SeS2. Tolerance to SeS2 was excellent, with no reported adverse events. CONCLUSION: The SeS2-based shampoo significantly reduces the time-to-relapse of moderate-to-severe SSD flares. Its tolerance was excellent, with no reported adverse events.

Selenium Disulfide-based shampoo applied for 4 weeks significantly improves dandruff and seborrheic dermatitis.

Seborrheic Dermatitis (SD) is a chronic and relapsing inflammatory condition accompanied by erythema, flaking and itching. Dandruff is a milder form of SD. Selenium disulfide (SeS2) is beneficial in both conditions. OBJECTIVES: to assess the efficacy of SeS2-based shampoo in dandruff/SD. MATERIALS & METHODS: an international, multicenter, observational study was conducted in 1407 adult subjects. SeS2- based shampoo was used 2 to 3 times per week for 4 weeks. Clinical efficacy criteria included improvement of hair, flaking, erythema and irritation on a scale from 0 to 5; investigator satisfaction was assessed at month 3 from 0 to 10. The subjects rated the impact of their hair problem (0 to 5), efficacy and satisfaction with SeS2-based shampoo at month 3. Tolerance was assessed throughout the study. RESULTS: At baseline, 68.2% had a flake severity score of 3-5, 49.9% an erythema severity score of 3-5, and 46.2% an irritation severity score of 3-5; 28.2% were bothered and 41.5% were very bothered. At study end, SD/D had at least clearly improved in 89.6% of subjects. All clinical signs had significantly (p<0.001) improved. 95.6% of subjects reported less pruritus. Significantly fewer (15.4%, p<0.0001) subjects were still bothered. The overall subject satisfaction score was 8.9±1.4; 97.6% of investigators were satisfied or very satisfied. Tolerance was good or very good in 98.8% of subjects. CONCLUSION: A SeS2-based shampoo applied 2 to 3 times per week is efficient and well tolerated in dandruff and SD.

Efficacy and safety of oral isotretinoin in the treatment of moderate to severe seborrheic dermatitis: a retrospective study.

BACKGROUND AND OBJECTIVES: Seborrheic dermatitis is a common, chronic, and recurrent inflammatory skin disease. There are few studies on oral isotretinoin in the treatment of seborrheic dermatitis. The aim of this research was to analyze the efficacy and safety of oral isotretinoin in the treatment of patients with moderate to severe seborrheic dermatitis. METHODS: This was a retrospective study. All included patients were diagnosed as moderate to severe seborrheic dermatitis and treated with oral isotretinoin from January 2019 to December 2020. Symptom Scale of Seborrheic Dermatitis (SSSD) was used to evaluate the overall severity status of disease. RESULTS: A total of 48 patients with moderate to severe seborrheic dermatitis were enrolled, of which 26 patients were treated with oral isotretinoin at a dose of 20 mg/day, and 22 patients were treated with oral isotretinoin at a dose of 10 mg/day. The duration of treatment was 2.42 ± 0.98 months (range: 2-6 months). The absolute SSSD values were 10.63 ± 1.02 for all 48 patients, 10.95 ± 1.15 and 10.30 ± 1.11 for patients with a dose of 20 and 10 mg/day, respectively. At the endpoint, there were no significant difference in SSSD values between the two groups (2.21 ± 0.24 vs. 2.35 ± 0.46, P = 0.18). The patients were satisfied with the two treatment schemes, and the difference was not statistically significant (P = 0.78). The most common side effect was cheilitis; however, no serious adverse events occurred in either group. CONCLUSIONS: When considering efficacy and safety, oral isotretinoin can be used to treat patients with moderate to severe seborrheic dermatitis.

Seborrheic dermatitis: topical therapeutics and formulation design.

Seborrheic dermatitis (SD) is a common dermatological disorder with symptoms that include skin flaking, erythema and pruritus. This review discusses the topical products available for treating SD, which target several aspects of disease pathobiology, including cutaneous microbial dysbiosis (driven by Malassezia yeast), inflammation, sebum production and skin barrier disruption. Among the various treatments available, zinc pyrithione (ZnPT) based products that exhibit anti-fungal action are the market leaders. A skin compartment approach is presented here for combining ZnPT exposure information with threshold levels for anti-fungal efficacy and toxicity, overall providing a comprehensive picture of ZnPT therapeutics and safety. While Malassezia yeast on the surface are effectively targeted, yeast residing beyond the superficial follicle may not receive adequate ZnPT for anti-fungal effect forming the basis for skin re-colonisation. Levels entering systemic circulation from topical delivery are well below toxic thresholds, however the elevated zinc levels within the viable epidermis warrants further investigation. Strategies to improve formulation design can be broadly classified as influencing 1) topical delivery, 2) therapeutic bioactivity, 3) skin mildness, and 4) sensory attributes. Successful SD treatment ultimately requires formulations that can balance efficacy, safety, and consumer appeal.

Botulinum Toxin in the Oily Skin: Advantage of a Multi-Needle Device for a Controlled Release.

BACKGROUND: Oily skin is one of the most common dermatological complaints. With the obligation to use masks to protect themselves from the Covid-19 virus, the problem has become even more evident. One of the treatments proposed is the use of onabotulinumtoxin-A injected sub-dermally. For an optimal result, the injections must be done on the whole area with numerous micro-injections located only in the sub-dermis. The procedure is often poorly tolerated by patients and sometimes accompanied by hematomas and bruises. This research aimed to test a disposable device to inject botulin toxin at 1.5 mm under the skin with a painless procedure and homogeneous distribution of the toxin. METHODS: We treated patients with oily skin with the injection of 100 IU of Onabotulinumtoxin-A (diluted in 5 ml of a saline solution). All the patients were evaluated after 2 weeks, one month, and three months. RESULTS: In 10 patients, after 15 days we observed a real improvement of the quality of the skin; for two, the results were present at the 1 month follow up. In all cases, the treatment appeared homogeneous in the entire face. All the patients considered the procedure virtually painless or with minimal discomfort. CONCLUSION: In accordance with other authors, we confirm the real advantages of micro-botulinum toxin for oily skin. Moreover, the use of this simple and innovative device allows a homogeneous distribution of the drug in the correct plane, without pain, and reduces the risks of common complications. J Drugs Dermatol. 2023;21(1): doi:10.36849/JDD.6900.