Association of air pollution with incidence of late-onset seborrhoeic dermatitis: a prospective cohort study in UK Biobank.

BACKGROUND: Late-onset seborrhoeic dermatitis seriously affects patients' quality of life. Studies have shown an association between air pollution and other inflammatory skin diseases. However, associations between air pollution exposures and the incidence of late-onset seborrhoeic dermatitis have not been elucidated. OBJECTIVES: To investigate air pollution's role in the incidence of late-onset seborrhoeic dermatitis. METHODS: We engaged a prospective cohort analysis utilizing the UK Biobank database. Exposure data spanning various years for specific air pollutants, namely particulate matter [PM; with an aerodynamic diameter of ≤ 2.5 µm (PM2.5), between 2.5 and 10 µm (PM2.5-10), ≤ 10 µm (PM10)] along with nitrogen oxides (NO plus NO2, denoted NOx) and NO2, were incorporated. Through a composite air pollution score constructed from five pollutants and employing Cox proportional hazards models, the relationship between air pollution and seborrhoeic dermatitis was delineated. RESULTS: Our examination of 193 995 participants identified 3363 cases of seborrhoeic dermatitis. Higher concentrations of specific pollutants, particularly in the upper quartile (Q4), were significantly linked to an elevated risk of seborrhoeic dermatitis. Notably, PM2.5, PM10, NO2 and NOx exhibited hazard ratios of 1.11, 1.15, 1.22 and 1.15, respectively. The correlation was further solidified with a positive association between air pollution score increments and onset of seborrhoeic dermatitis. Intriguingly, this association was accentuated in certain demographics, including younger men, socioeconomically deprived people, smokers, daily alcohol consumers, and those engaging in regular physical activity. CONCLUSIONS: Our findings revealed that air pollution exposures were associated with incidence of late-onset seborrhoeic dermatitis. These results emphasize the importance of preventing environmental air pollution exposures to mitigate the risk of developing the condition.

A bibliometric and visual analysis of the research status and hotspots of seborrheic dermatitis based on web of science.

BACKGROUND: Seborrheic dermatitis (SD) is a common chronic inflammatory skin disease. In recent years, significant progress has been made in the field of SD, but there has been no bibliometric research yet. This study aims to use bibliometric methods to analyze the current research status and hot topics of SD, to understand further the research trends and future development prospects in this field. METHODS: Retrieve core literature on SD from the Web of Science database and conduct a detailed analysis using CiteSpace and VOSviewer software based on factors such as publication volume, countries (regions), research institutions, journals, authors, highly-cited papers, and keywords. RESULTS: From 1996 to 2024, a total of 1436 publications were included in the bibliometric analysis. The number of publications has shown an increasing trend year by year. The USA is the leading country in this field of research. The University of California System is the primary research institution. The International Journal of Dermatology is the journal with the highest number of publications. The author Yang Won Lee has the highest number of publications, while the article "Seborrheic Dermatitis" (2004) by Gupta, A.K. has been cited the most. "Seborrheic dermatitis" is the most frequently occurring keyword. The main research hotspots and frontiers in SD are as follows: (1) The relationship between SD and other skin diseases is a popular research topic; (2) Malassezia and inflammation are current research hotspots in SD; and (3) Focusing on antifungal and anti-inflammatory treatments for SD is the current frontier direction in this field. CONCLUSION: This study is a summary of the current status and hot trends of SD research, which helps clinical doctors and researchers quickly understand the insights and valuable information of SD research and provides reference for clinical decision-making and finding future research directions.

Eczema, facial erythema, and seborrheic dermatitis symptoms among young adults in China in relation to ambient air pollution, climate, and home environment.

A questionnaire survey on dermal symptoms and home environment was performed in eight Chinese cities (40 279 participants). Data on city level temperature, precipitation, PM10 , NO2, and gross domestic product (GDP) per capita were collected. In total, 2.2% had eczema, 2.4% facial erythema (FE) and 2.6% seborrheic dermatitis symptoms (SD). Higher temperature was associated with eczema (OR = 1.09). Higher GDP per capita was related to less SD. Higher PM10 was related to SD. Suburban living was protective for eczema (OR = 0.77) (vs. urban). Living in old buildings (built before 1991) was related to eczema (OR = 1.42). Living near heavily trafficked roads was related to FE (OR = 1.33) and SD (OR = 1.35). Having new furniture was related to all symptoms (OR = 1.26-1.47). Burning mosquito coils (OR = 1.37-1.57) and incense (OR = 1.33-1.37) were associated with eczema, FE, or SD. Presence of cockroaches and rats/mice was associated with FE or SD (OR = 1.31-1.40). Using air conditioner, daily cleaning and frequently exposing bedding to sunshine were protective (OR = 0.60-0.83). In conclusion, higher temperature, higher PM10 , urban living, living near heavily trafficked roads, old buildings, new furniture, burning mosquito coils and incense, and presence of cockroaches/rats/mice increased the risk of eczema, FE, or SD. Higher GDP, air conditioner, daily cleaning, and exposing bedding to sunshine were protective.

Scalp involvement in patients referred for patch testing: Retrospective cross-sectional analysis of North American Contact Dermatitis Group data, 1996 to 2016.

BACKGROUND: Scalp conditions are often multifactorial. OBJECTIVE: To characterize patients with scalp involvement and patch-testing outcomes. METHODS: Retrospective cross-sectional analysis of North American Contact Dermatitis Group data (1996-2016). Study groups included patients with scalp involvement (≤3 anatomic sites coded) with or without additional sites. RESULTS: A total of 4.8% of patients (2331/48,753) had scalp identified as 1 of up to 3 affected anatomic sites. Approximately one-third of "scalp-only" individuals had a specific primary diagnosis of allergic contact dermatitis (38.6%), followed by seborrheic dermatitis (17.2%) and irritant contact dermatitis (9.3%). When adjacent anatomic sites were affected, allergic contact dermatitis was more frequently identified as the primary diagnosis (>50%). The top 5 currently clinically relevant allergens in scalp-only patients were p-phenylenediamine, fragrance mix I, nickel sulfate, balsam of Peru, and cinnamic aldehyde. Methylisothiazolinone sensitivity was notable when adjacent anatomic sites were involved. The top 3 specifically identified sources for scalp-only allergens were hair dyes, shampoo/conditioners, and consumer items (eg, hair appliances, glasses). LIMITATIONS: Tertiary referral population. CONCLUSION: Isolated scalp involvement was less likely to be associated with allergic contact dermatitis than when adjacent anatomic sites were involved. Overlap with multiple diagnoses was frequent, including seborrheic dermatitis, irritant dermatitis, other dermatoses, or all 3. p-Phenylenediamine was the most common allergen.

Hand dermatitis in adults referred for patch testing: Analysis of North American Contact Dermatitis Group Data, 2000 to 2016.

BACKGROUND: Hand eczema (HE) is a heterogeneous and burdensome disorder. OBJECTIVE: To characterize the clinical characteristics, etiologies and allergen relevance in adults with HE referred for patch testing. METHODS: Retrospective analysis (2000-2016) of North American Contact Dermatitis Group data (n = 37,113). RESULTS: Overall, 10,034 patients had HE, with differences of overlap between allergic contact, irritant contact, and atopic dermatitis. Allergic contact HE fluctuated, whereas atopic HE steadily increased, and irritant HE decreased over time. HE was associated with higher proportions of positive patch tests (67.5% vs 63.8%; χ2, P < .0001). The five most common clinically relevant allergens were methylisothiazolinone, nickel, formaldehyde, quaternium-15, and fragrance mix I. HE was associated with significantly higher odds of positive patch test reactions and clinical relevance in 13 and 16 of the 25 most common allergens, respectively, including preservatives, metals, topical medications, and rubber accelerators. LIMITATIONS: No data on HE phenotype. CONCLUSION: HE in adults was associated with higher proportions of positive patch tests, with a heterogeneous profile of allergens. Patch testing remains an important tool in the evaluation of patients with HE.

An update on the microbiology, immunology and genetics of seborrheic dermatitis.

The underlying mechanism of seborrheic dermatitis (SD) is poorly understood but major scientific progress has been made in recent years related to microbiology, immunology and genetics. In light of this, the major goal of this article was to summarize the most recent articles on SD, specifically related to underlying pathophysiology. SD results from Malassezia hydrolysation of free fatty acids with activation of the immune system by the way of pattern recognition receptors, inflammasome, IL-1ß and NF-kB. M. restricta and M. globosa are likely the most virulent subspecies, producing large quantities of irritating oleic acids, leading to IL-8 and IL-17 activation. IL-17 and IL-4 might play a big role in pathogenesis, but this needs to be further studied using novel biologics. No clear genetic predisposition has been established; however, recent studies implicated certain increased-risk human leucocyte antigen (HLA) alleles, such as A*32, DQB1*05 and DRB1*01 as well as possible associations with psoriasis and atopic dermatitis (AD) through the LCE3 gene cluster while SD, and SD-like syndromes, shares genetic mutations that appear to impair the ability of the immune system to restrict Malassezia growth, partially due to complement system dysfunction. A paucity of studies exists looking at the relationship between SD and systemic disease. In HIV, SD is thought to be secondary to a combination of immune dysregulation and disruption in skin microbiota with unhindered Malassezia proliferation. In Parkinson's disease, SD is most likely secondary to parasympathetic hyperactivity with increased sebum production as well as facial immobility which leads to sebum accumulation.

Evaluation of the effects of COVID-19 pandemic on hair diseases through a web-based questionnaire.

AIM: Current quarantine conditions are a difficult process for individuals and can worsen the psychological state. Increased psychosocial stress can affect the course of many common "stress-sensitive" skin conditions. This study examined the possible effects of coronavirus disease 2019 (COVID-19) on hair and scalp diseases such as telogen effluvium (TE), alopecia areata (AA), and seborrheic dermatitis (SD) in individuals who had to stay at home for a long time and the patients' methods of dealing with these diseases. METHODS: The study was conducted using an online questionnaire. All the individuals were asked questions about pre- and post-pandemic TE, AA, and SD. Participants with complaints were asked what they did for treatment. RESULTS: During the pandemic, TE was seen in 27.9% of the participants, AA on the scalp was seen in 2.8%, AA on the face was seen in 2.5%, and SD was seen in 19.9%. Applying to a dermatologist for complaints during the pandemic was lower than before pandemic. TE was higher in women before and during the pandemic. CONCLUSION: It was found that the rates of referring to a dermatologist for the complaints before the pandemic varied between 15% and 28% and that these rates decreased significantly during the pandemic (2.5%-12.5%).

Risk Factors for Seborrhoeic Dermatitis Flares: Case-control and Case-crossover Study.

Patients with flares of seborrhoeic dermatitis were compared with control outpatients seen during the same time-period in a case-control study, and with themselves while in remission in a case-crossover study. All patients consulted the same office-based dermatologist. During the study period, 189 cases and 189 controls were included in the case-control study, and 81 cases in the case-crossover study. Multivariate analysis was performed. Case-control study results were the following: past history of tobacco consumption (odds ratio (OR) 2.2 (95% confidence interval (CI) 1.1-4.6)), conflict as a dispute during the past month (OR 10.6 (95% CI 1.0-114.3)), alcohol consumption on a regular basis (OR 10.2 (95% CI 2.0-52.6)), and higher level of stress during the past month (OR 8.2 (95% CI 3.4-19.9)). Case-crossover study results were the following: higher level of stress during the past month (OR 4.5 (1.7-12.2)), association borderline significant for higher level of alcohol consumption (OR 5.4 (0.8-34.9)). These risk factors for flares of seborrhoeic dermatitis should be taken into account carefully in the daily management of seborrhoeic dermatitis.

Epidemiology and dermatological comorbidity of seborrhoeic dermatitis: population-based study in 161 269 employees.

BACKGROUND: Seborrhoeic dermatitis is a common but epidemiologically poorly researched chronic skin disease. OBJECTIVES: To characterize the prevalence and dermatological comorbidity of seborrhoeic dermatitis in Germany. METHODS: In the course of voluntary company skin checks, full-body examinations were carried out in more than 500 companies by experienced dermatologists and documented electronically. RESULTS: In total, 161 269 participants were included (men 55·5%, mean age 43·2 ± 10·9 years). Seborrhoeic dermatitis was identified in 3·2% (men 4·6%, women 1·4%). A significant difference was found between age groups (2·0% in < 35; 3·6% in 35-64; 4·4% ≥ 65 years). The most frequent concomitant skin conditions were: folliculitis [17·0%, 95% confidence interval (CI) 15·9-18·1], onychomycosis (9·1%, 95% CI 8·3-10·0), tinea pedis (7·1%, 95% CI 6·3-7·8), rosacea (4·1%, 95% CI 3·6-4·7), acne (4·0%, 95% CI 3·4-4·5) and psoriasis (2·7%, 95% CI 2·3-3·2). Regression analysis revealed the following relative dermatological comorbidities when controlling for age and sex: folliculitis [odds ratio (OR) 2·1, 95% CI 2·0-2·3], contact dermatitis (OR 1·8, 95% CI 1·1-2·8), intertriginous dermatitis (OR 1·8, 95% CI 1·4-2·2), rosacea (OR 1·6, 95% CI 1·4-1·8), acne (OR 1·4, 95% CI 1·2-1·7), pyoderma (OR 1·4, 95% CI 1·1-1·8), tinea corporis (OR 1·4, 95% CI 1·0-2·0), pityriasis versicolor (OR 1·3, 95% CI 1·0-1·7) and psoriasis (OR 1·2, 95% CI 1·0-1·5). CONCLUSIONS: Seborrhoeic dermatitis is a common disease, which is more prevalent in men and older people, and it has an increased rate of dermatological comorbidity. However, absolute differences in the prevalence of comorbidities are small and negligible. Nevertheless, the findings underline the need for integrated, complete dermatological diagnostics and therapy.

Prevalence, predictors and comorbidity of dry skin in the general population.

BACKGROUND: Dry skin is a frequent and multifaceted condition which can be associated with skin irritation, itch, patient discomfort and manifest skin disease. In spite of being frequent, little is known about the epidemiology of dry skin in the population. OBJECTIVE: To determine the prevalence of dry skin in the German adult population. METHODS: Data of 48 630 employed persons were assessed on a cross-sectional level in whole-body examinations by experienced dermatologists during company-based skin screenings conducted in 343 German companies. Next to the current dermatologic findings, age, gender, allergies, atopic diseases and the skin type were assessed. RESULTS: In total, n = 14 300 persons (29.4%) were rated as having xerotic skin. Older age but not gender was associated with xerosis. In the regression analyses controlling for age and gender, dry skin was a significant predictor for: axillary dermatitis (OR: 4.51; CI 2.70-7.54), atopic eczema (OR: 3.99; CI 3.42-4.65), exsiccation eczema (OR: 2.96; CI 2.40-3.65), psoriasis (OR: 1.57; CI 1.38-1.78), plantar warts (OR: 1.42; CI 1.26-1.60), seborrhoeic dermatitis (OR: 1.28; CI 1.16-1.42) and atopic disposition (OR: 1.17; CI 1.12-1.22). CONCLUSION: Dry skin is a frequent condition in the adult general population and needs special attention. Known risk factors may facilitate identifying patients at risk for deterioration.

Prevalence and determinants of seborrhoeic dermatitis in a middle-aged and elderly population: the Rotterdam Study.

BACKGROUND: Seborrhoeic dermatitis is a chronic relapsing inflammatory skin disease with unclear pathophysiological mechanisms. OBJECTIVES: To establish which lifestyle and physiological determinants are associated with seborrhoeic dermatitis. METHODS: Seborrhoeic dermatitis was diagnosed by a trained physician during a full-body skin examination within the Rotterdam Study, a prospective population-based cohort study in middle-aged and elderly people. The current design is a comparative cross-sectional study embedded in the Rotterdam Study. Potential factors were identified from the literature and analysed in a multivariable logistic regression, including: age, sex, obesity, skin colour, stress, depression, education level, hypertension, climate, xerosis cutis, alcohol and tobacco use. RESULTS: Of the 5498 participants, 788 participants were diagnosed with seborrhoeic dermatitis (14·3%). We found associations between seborrhoeic dermatitis and male sex [adjusted odds ratio (OR) 2·09, 95% confidence interval (CI) 1·77-2·47], darker skin (adjusted OR 0·39, 95% CI 0·22-0·69), season (summer vs. winter: adjusted OR 0·63, 95% CI 0·48-0·82) and generalized xerosis cutis (adjusted OR 1·41, 95% CI 1·11-1·80). CONCLUSIONS: Seborrhoeic dermatitis is one of the most common inflammatory dermatoses in middle-aged and elderly individuals, especially during winter. Men, and people with a light and dry skin were most likely to have seborrhoeic dermatitis.

The worldwide diversity of scalp seborrhoea, as daily experienced by seven human ethnic groups.

OBJECTIVE: The re-greasing process and kinetics of the human scalp, post-shampooing, have been previously documented, in vivo, on a few Caucasian subjects. The objective of the presented research was to extend such knowledge over seven different ethnic groups. METHODS: The post-shampooing re-greasing kinetics of the scalp was studied on 1325 subjects (women and men of two distinct age classes) from seven different ethnic groups in their residential and native country. Sebum amounts were determined onto small shaved scalp areas at various times post-shampooing, using the Sebumeter® technique. RESULTS: As previously published on Caucasian subjects, scalp re-greasing process follows a hyperbolic-like kinetics over days. However, amounts of collected sebum highly vary with ethnicity. As recorded through the casual level (CL) at the equilibrium phase, 2-3 days post-shampooing, the highest amount of sebum was found in African American subjects, followed in descending order by Caucasian American, Japanese, Chinese, Thai, Caucasian European and Indian subjects, the latter showing very low values. Lower amounts of sebum were recorded in the older age class in all ethnics, as compared to the younger one, and male subjects were found higher sebum producers than women, irrespective of ethnicity. CONCLUSION: The kinetics and slopes of the re-greasing process of the human scalp appear similar in all ethnic groups studied. However, striking quantitative differences are found between the seven ethnic groups, resulting from different sebaceous production levels and scalp hygiene routines.

Is seborrhoeic dermatitis associated with a diffuse, low-grade folliculitis and progressive cicatricial alopecia?

An association between adult scalp seborrhoeic dermatitis and cicatricial hair loss has not previously been convincingly established. This study seeks to demonstrate a unique relationship between a clinically identifiable chronic scalp dermatitis-folliculitis with the characteristic histological features of low-grade inflammatory fibrosing alopecia, resulting in a distinctive progressive cicatricial alopecia which we believe is prevalent and hitherto unrecognised, and befits the description of seborrhoeic folliculitis. The clinical, epidemiological and histopathological features of seborrhoeic folliculitis are demonstrated to establish its unique status among the disorders of adult diffuse cicatricial alopecia.

Presence, species distribution, and density of Malassezia yeast in patients with seborrhoeic dermatitis - a community-based case-control study and review of literature.

Malassezia yeast belongs to the normal cutaneous flora and under certain conditions it causes seborrhoeic dermatitis (SD). There is no culture-based study about the presence and density of the Malassezia in SD patients in Serbia. Aim was to show the presence, species distribution and density of Malassezia in patients with SD on lesional skin (LS) and non-lesional skin (NLS) and healthy controls (HC) and to compare data between Serbia and other countries. The study included 70 HC and 60 patients with SD in the study group (SG). Isolation, identification and examination of density of Malassezia colony-forming units from LS and NLS were performed. Malassezia was found more frequently in the SG than in HC, 90% and 60%, respectively (P < 0.01). The most frequent isolates in SG on LS were M. slooffiae (26%), followed by M. globosa (17%) and M. sympodialis (17%). The yeast density was much higher on LS of SG than on NLS of SG or in the HC group (P < 0.05). Higher density of Malassezia was shown on LS of SG than on NLS of SG and HC. M. slooffiae is the most prevalent species in SD patients in Serbia. This study demonstrated a positive relationship between severity of SD and presence of Malassezia spp.

[Indicator condition guided human immunodeficiency virus requesting in primary health care: results of a collaboration]. / Solicitud de VIH en condiciones indicadoras en atención primaria: resultados de una colaboración.

INTRODUCTION: The search of HIV infected patients guided by indicator conditions (IC) is a strategy used to increase the early detection of HIV. The objective is to analyze whether a collaboration to raise awareness of the importance of early detection of HIV in 3 primary care centers influenced the proportion of HIV serology requested. METHODS: Multicenter retrospective study was conducted comparing the baseline and a post-collaboration period. The collaboration consisted of training sessions and participation in the HIDES study (years 2009-2010). Patients between 18 and 64 years old with newly diagnosed herpes zoster, seborrheic eczema, mononucleosis syndrome, and leucopenia/thrombocytopenia in 3 primary care centers in 2008 (baseline period) and 2012 (post-collaboration period). The sociodemographic variables, HIV risk conditions, requests for HIV serology, and outcomes were evaluated. RESULTS: A total of 1,219 ICs were included (558 in 2008 and 661 in 2012). In 2008 the number of HIV tests in patients with an IC was 3.9%, and rose to 11.8% in 2012 (P<.0001). The HIV infection rate was 2.2% (95% CI: 0.4-7.3) (n=2). It was estimated that 25 new cases (12 in 2008 and 13 in 2012) would have been diagnosed if they had performed the test on all patients with IC. Predictors of HIV request were, having an IC in 2012, a younger age, having an mononucleosis syndrome, and not being Spanish. CONCLUSIONS: The HIV request demand tripled, after the collaboration with primary care centers, however in 88% the test was not requested, resulting in diagnostic losses. New strategies are needed to raise awareness of the importance of early detection of HIV.