A noninvasive method to assess skin irritation and compromised skin conditions using simple tape adsorption of molecular markers of inflammation

Background/aims: We have developed a simple noninvasive method to assess inflammatory changes in human skin, even in the absence of visible clinical irritation. Our approach is based on a simple tape (Sebutape^®) adsorption method to recover molecular mediators of skin inflammation (e.g., cytokines). This procedure has been used to investigate baseline cytokine levels on skin, to assess normal skin condition and to evaluate changes due to chemical insult, existing dermatitis, or sun exposure. Methods: In clinical studies, Sebutape was applied to normal appearing uncompromised skin, as well as to compromised (diaper or heat rash), chemically treated (sodium laurel sulfate), or sun-exposed skin. Sebutape was applied to the skin for a 1 min collection interval. Tapes were extracted in saline using a 10 min sonication, and the extracts were analyzed for human interleukin-1α (IL-1α), IL-1 receptor antagonist (IL-1RA) and IL-8 using commercial immunoassay test kits. The cytokine levels recovered from each tape extract were normalized to total protein (TP) levels. In infant product use tests, the severity of skin irritation (diaper and heat rash or erythema) was also assessed using a visual grading scale. Results: The method itself caused minimal, if any, skin damage. Additionally, Sebutape was shown to quantitatively adsorb detectable levels of cytokine from normal-appearing (control) or compromised (e.g., rashed or chemically treated) skin. In infant studies, significant increases in IL-1α levels were found in skin exhibiting diaper rash, heat rash and erythema compared with normal appearing control skin sites. When these results were normalized to total protein levels recovered from each tape, the significance was maintained. A positive correlation (r²=0.82) existed between IL-1RA levels and diaper rash severity. Significant increases in IL-8 levels were recovered from diaper rash versus control skin sites. There were differences in baseline cytokine levels in normal skin related to body site and sun exposure. The IL-1RA/IL-1α ratios for sun-exposed skin of the face and lower leg were significantly (P<0.05) higher (3–6-fold) than those for skin sites that typically receive minimal sun exposure (i.e., underarm, upper leg and upper back). There was a significant increase in IL-1α and a directional increase in IL-8 levels in adult skin sites treated with the irritant, sodium lauryl sulfate, even in the absence of visible skin irritation (erythema). Conclusion: Our results demonstrate that this method is a useful noninvasive technique for assessing skin inflammatory events. In addition, the method is simple and easily applied in a clinical setting, whether on infants or adults.     

头皮屑和头皮脂溢性皮炎患者头皮脂类水平及马拉色菌数量的检测

目的:测定有头皮屑及头皮脂溢性皮炎患者与正常受试者头皮表面脂类水平及马拉色菌数量的差异。方法:使用sebumeter于洗发后连续4天测量受试者额、顶、枕部头皮皮脂,并于第4天真菌镜检马拉色菌,记录马拉色菌数量。结果:有头皮屑及头皮脂溢性皮炎组与正常对照组相比,马拉色菌数量显著增高,具有统计学意义(P<0.05)。头皮脂溢性皮炎组较头皮屑组的马拉色菌数量显著增高,具有统计学意义(P<0.05)。在头皮屑及头皮脂溢性皮炎组中,随着炎症程度加重,检出的马拉色菌孢子数增多。结论:马拉色菌感染可能与头皮屑多和脂溢性皮炎有关。     

Quantitative microbiology of the scalp in non-dandruff, dandruff, and seborrheic dermatitis.

The composition of the scalp microflora was assessed quantitatively in normal individuals and in patients with dandruff and seborrheic dermatitis, disorders characterized by increasing scaling. Three organisms were constantly found: (1) Pityrosporum, (2) aerobic cocci, and (3) Corynebacterium acnes. Pityrosporum (mainly Pityrosporum ovale) made up 46% of the total microflora in normals, 74% in dandruff, and 83% in seborvheic dermatitis. The geometric mean number of organisms per cm-2 in non-dandruff subjects was 5.04 times 10-5; 9.22 times 10-5 in dandruff subjects; and 6.45 times 10-5 in those with seborrheic dermatitis. The cocci were dominantly Baird-Parker type SII and no quantitative or qualitative change occurred in the scaling disorders. C. acnes comprised 26% of the flora on the normal scalp, 6% in dandruff, and only 1% in seborrheic dermatitis. These results differ significantly from previous reports which describe a much more complex microflora and suggest an etiologic role for microorganisms in dandruff.     

Characterization of the major bacterial–fungal populations colonizing dandruff scalps in Shanghai,China, shows microbial disequilibrium

Dandruff is a scalp disorder characterized by the formation of flaky white‐yellowish scales due to an altered proliferation and differentiation status; a disrupted barrier function; a decrease in the level of hydration and of natural moisturizing factors (NMF) in the scalp, with a persistent and relapsing inflammatory condition. It was recently reported that an imbalance between bacterial and fungal species colonizing the scalp of French volunteers was associated with dandruff condition. The purpose of the present study was to analyze the major bacterial and fungal species present on the scalp surface of Chinese volunteers and to investigate possible region‐related variation in the microbiota linked to dandruff condition. The data obtained from the Chinese populations were highly similar to those obtained in France, confirming that dandruff scalps are associated with a higher incidence of Malassezia restricta and Staphylococcal sp. The ratios of Malassezia to Propionibacterium and Propionibacterium to Staphylococcus were also significantly higher in the dandruff volunteers as compared to normal volunteers, suggesting that equilibrium between the major bacterial and fungal taxa found on the normal scalps is perturbed in the dandruff scalps. The main difference between the French and Shanghai subjects was in their Staphylococcal biota. The results obtained in China and in France suggest that targeting one particular Malassezia sp. by antifungals instead of using large spectrum antifungals and rebalancing the dandruff scalp microbiota could be common approach to improve dandruff condition in the two countries.     

Baseline sebum IL‐1α is higher than expected in afro‐textured hair: a risk factor for hair loss?*

Objective To investigate changes in sebum cytokines in response to hair cosmetics. Design and setting A prospective study at a University hospital. Methods We used a novel method for scalp surface sebum collection (Sebutape^®) on three visits, sequentially a week apart, to investigate changes in six cytokines in 36 healthy women before and after shampoo and compared various chemical treatments (ammonium thioglycolate, “lye” sodium hydroxide and “no‐lye” guanidine hydroxide relaxers) performed by a professional hairdresser. Results Significant levels detected were IL‐1 alpha (IL‐1α) and IL‐1 receptor antagonist (IL‐1ra), which were higher in untreated scalp vs. forehead: P < 0.001. Baseline levels of scalp sebum IL‐1α were 18 times higher than IL‐1ra. The levels of IL‐1α decreased uniformly after shampoo (visit 1) and various chemical treatments (both crown and vertex all P < 0.001 – visit 2) but increased on follow‐up at visit 3. Decreases in IL‐1ra mimicked IL‐1α at the vertex [after shampoo (P = 0.018) and visit 3 (P = 0.014)], but not on the crown, a finding which may suggest site‐specific scalp predisposition to inflammation. The ratio of IL‐1ra/IL‐1α increased in all groups after all chemical treatments and on follow‐up (all P < 0.001) but was surprisingly not significantly different from natural hair that underwent shampoo. Limitations A wider cytokine panel may reveal response differences in treatment groups. Conclusions Baseline inflammatory scalp cytokines are higher than expected and reduce with shampooing. Scrutiny of the influence of hair moisturizer formulations and shampoo intervals and studies investigating pro‐fibrotic cytokines are required. This may elucidate the predilection of afro‐textured hair to scarring alopecia.     

Safety and efficacy of ciclopirox 1% shampoo for the treatment of seborrheic dermatitis of the scalp in the US population: results of a double-blind, vehicle-controlled trial

Background Seborrheic dermatitis is a common inflammatory skin disorder. Yeasts of the genus Malassezia have been implicated in the etiology of seborrheic dermatitis, although this connection remains controversial. Ciclopirox is a synthetic, hydroxypyridone‐derived, broad‐spectrum antifungal agent with anti‐inflammatory properties. Methods A total of 499 US patients with seborrheic dermatitis of the scalp were randomized to apply either ciclopirox shampoo 1% or vehicle twice weekly for 4 weeks. The main efficacy parameters were based on 6‐point ordinal scales describing the disease's signs and symptoms (scaling, erythema and itching) and a 6‐point scale providing a global evaluation of the status of seborrheic dermatitis. Results Ciclopirox was significantly better than vehicle in effectively treating seborrheic dermatitis. ‘Effective treatment’ (score of 0 or 1 for disease status, scaling and erythema) was achieved in 26.0% of ciclopirox‐treated patients compared with 12.9% of vehicle‐treated patients (P = 0.0001; OR: 2.383, 95% CI: 1.494–3.799). The majority of subjects experienced adverse events that were mild in intensity, with skin and appendage reactions the most commonly reported, at similar frequency in both groups. Conclusions Ciclopirox shampoo 1% is effective and safe in the treatment of seborrheic dermatitis of the scalp.     

Randomized study comparing the efficacy and tolerance of a lipohydroxy acid shampoo to a ciclopiroxolamine shampoo in the treatment of scalp seborrheic dermatitis

Background The success of a dandruff treatment depends not only on the ability of a shampoo to control dandruff, but also on patient compliance, which is closely linked to the cosmetic attributes of the product. Aim The aim of this study was to compare efficacy, tolerance, and cosmetic properties of a LHA Shampoo [containing 0.1% lipohydroxy acid (LHA) and 1.3% salicylic acid] to a CPO shampoo [containing 1.5% ciclopiroxolamine (CPO), 3% salicylic acid, and 0.5% menthol] in subjects with seborrheic dermatitis (SD) of the scalp. Methods One hundred subjects with mild to moderate scalp SD were randomized to receive either the LHA shampoo or the CPO shampoo every 2 days for 4 weeks. Efficacy and tolerance were evaluated at days 0, 14, and 28. Results The LHA and the CPO shampoo both decreased symptoms of scale, erythema, itching, cutaneous discomfort, and dryness from baseline to day 28. A higher percentage of patients showed improvement in the group treated with the LHA formulation than in the group treated with the CPO formulation, but the difference did not reach statistical significance. At day 28, the tolerance and the global efficacy of the LHA shampoo were significantly better (P = 0.03 and P = 0.01, respectively) than those of the CPO shampoo. Furthermore, the cosmetic acceptability was better or significantly better for all the endpoints evaluated for the LHA shampoo (P = 0.02 for cleaning, P = 0.04 for lathering). Conclusion In conclusion, these results demonstrated that the lipohydroxy acid shampoo evaluated in this study is a more convenient, efficient, safe, and well‐tolerated cosmetic treatment for mild‐to‐moderate seborrheic dermatitis of the scalp than a ciclopiroxolamine shampoo.     

A multicenter randomized trial of ketoconazole 2% and zinc pyrithione 1% shampoos in severe dandruff and seborrheic dermatitis

Ketoconazole (KET) and zinc pyrithione (ZPT) are compounds active against the Malassezia spp. yeasts, which are believed to play a major role in dandruff and seborrheic dermatitis. We compared the efficacy and safety of KET 2% and ZPT 1% in shampoo formulations for the alleviation of severe dandruff and seborrheic dermatitis. This open randomized, parallel-group trial began with a 2-week run-in phase during which subjects applied a neutral non-antidandruff shampoo. It was followed by a 4-week randomized treatment phase and a subsequent 4-week follow-up phase without treatment. Shampooing during the treatment period was carried out twice weekly for the KET group and at least twice weekly for the ZPT group in accordance with the label instructions. A total of 343 subjects were recruited to enter the trial. Of the 331 eligible volunteers, 171 were randomized to KET 2% and 160 to ZPT 1%. Clinical assessments were performed. Beneficial effects were evidenced for both medicated shampoos, but the effect was significantly better for KET 2%, which achieved a 73% improvement in the total dandruff severity score compared with 67% for ZPT 1% at week 4 (p < 0.02). The recurrence rate of the disease was also significantly lower following KET 2% treatment than following ZPT 1% treatment. As a consequence, the overall clearing of the skin condition at the end of treatment and follow-up phase was in favor of the KET 2% formulation (p = 0.004). Side effects were minimal. It is concluded that after a 4-week treatment, KET 2% shampoo was significantly superior to ZPT 1% shampoo in the treatment of subjects with severe dandruff or seborrheic dermatitis of the scalp. It is our assumption that this difference is noticeable for the patient and as a consequence relevant. Both formulations were well tolerated.     

头皮屑和头皮脂溢性皮炎患者头皮脂类水平的检测

目的探讨头皮屑及头皮脂溢性皮炎患者与正常受试者头皮不同部位表面脂类水平。方法使用se-bumeter于洗发后连续4天测量头皮屑及头皮脂溢性皮炎患者和健康对照者额、顶、枕部头皮皮脂。结果头皮屑及头皮脂溢性皮炎组头皮表面脂量与额部在前3天、顶部在第2,3天、枕部在第2,3,4天均较对照组显著性增高,有统计学意义(P<0.05);头皮屑及头皮脂溢性皮炎组第1,2,3,4天额部、顶部头皮表面脂量均显著高于枕部(P<0.05)。结论头皮屑及头皮脂溢性皮炎组和对照组同一天枕部头皮表面脂量明显少于额部和顶部,而额部和顶部的头皮表面脂量接近。头皮屑及头皮脂溢性皮炎患者额、顶、枕部头皮表面脂量分别于第3,2,3天达到饱和。     

Clinical efficacies of topical agents for the treatment of seborrheic dermatitis of the scalp: A comparative study

Previous studies have shown that topical steroid and shampoo containing zinc pyrithione provide clinical benefits for treatment of scalp seborrheic dermatitis. But the clinical efficacy of topical tacrolimus, a newly developed calcineurin inhibitor on seborrheic dermatitis, is not well investigated yet. We wanted to compare the clinical efficacy of topical tacrolimus with that of conventional treatment (zinc pyrithione shampoo and topical betamethasone) for treatment of seborrheic dermatitis of the scalp. Patients with seborrheic dermatitis of the scalp were randomly allocated to receive topical betamethasone, topical tacrolimus or zinc pyrithione shampoo. Some patients were instructed to continue the treatments for 8 weeks and the others to discontinue the treatments at week 4. We evaluated the efficacy using a clinical severity score, dandruff score and sebum secretion at baseline, week 4 and week 8. All treatment groups showed significant improvements in clinical assessment after 4 weeks. While the patients treated by zinc pyrithione improved continuously even after cessation of the treatment, the patients treated by betamethasone lotion or tacrolimus ointment were aggravated clinically. Topical tacrolimus was as effective as topical betamethasone, and showed more prolonged remission than topical betamethasone. To treat seborrheic dermatitis of the scalp, we think that the combination therapy of topical steroid or topical tacrolimus, and zinc pyrithione is recommended.     

Three etiologic facets of dandruff and seborrheic dermatitis: Malassezia fungi, sebaceous lipids, and individual sensitivity

Application of new molecular and biochemical tools has greatly increased our understanding of the organisms, mechanisms, and treatments of dandruff and seborrheic dermatitis. Dandruff results from at least three etiologic factors: Malassezia fungi, sebaceous secretions, and individual sensitivity. While Malassezia (formerly P. ovale) has long been a suspected cause, implicated by its presence on skin and lipophylic nature, lack of correlation between Malassezia number and the presence and severity of dandruff has remained perplexing. We have previously identified the Malassezia species correlating to dandruff and seborrheic dermatitis. In this report, we show that dandruff is mediated by Malassezia metabolites, specifically irritating free fatty acids released from sebaceous triglycerides. Investigation of the toxic Malassezia free fatty acid metabolites (represented by oleic acid) reveals the component of individual susceptibility. Malassezia metabolism results in increased levels of scalp free fatty acids. Of the three etiologic factors implicated in dandruff, Malassezia, sebaceous triglycerides, and individual susceptibility, Malassezia are the easiest to control. Pyrithione zinc kills Malassezia and all other fungi, and is highly effective against the Malassezia species actually found on scalp. Reduction in fungi reduces free fatty acids, thereby reducing scalp flaking and itch.     

Dermoscopic Findings in Scalp Psoriasis and Seborrheic Dermatitis; Two New Signs; Signet Ring Vessel and Hidden Hair

Background:

Psoriasis and seborrheic dermatitis are both chronic erythemato-squamous dermatoses that can involve the scalp. It may be difficult to differentiate these two diseases when there is isolated scalp involvement. Recently, trichoscopy is commonly used to differentiate noncicatricial alopecias including psoriasis and seborrheic dermatitis that can lead to telogen effluvium (TE).

Objectives:

The objective of this study is to evaluate the trichoscopic figures that may help to differentiate scalp psoriasis and seborrheic dermatitis.

Materials and Methods:

Thirty one with scalp psoriasis and 112 patients with seborrheic dermatitis were enrolled. Trichoscopic examinations were performed using a videodermatoscope (MoleMax 3^®). Trichoscopic findings of scalp psoriasis and seborrheic dermatitis were compared with each other, with 100 healthy individuals and with other noncicatricial alopecias including female androgenetic alopecia (FAGA) (n: 138), male androgenetic alopecia (n: 63), FAGA of male pattern (FAGA.M) (n: 5), alopecia areata (39), TE (n: 22) and trichotillomania (n: 4).

Results:

Atypical red vessels, red dots and globules (RDG), signet ring vessels (SRV), structureless red areas and hidden hairs (HH) were statistically more common in psoriasis while twisted red loops and comma vessels (CV) in seborrheic dermatitis. RDG were considered as the characteristic videodermatoscopic figure for psoriasis and arborizing red lines and CV for seborrheic dermatitis. In comparison with previous reports, our study yielded two new trichoscopic structures supporting the diagnosis of psoriasis; HH and SRV. Besides, according to our study, CV were described for the first time in seborrheic dermatitis and considered to be specific for seborrheic dermatitis.

Conclusion:

This study confirmed that trichoscopy might be useful in differentiating scalp psoriasis and seborrheic dermatitis from each other and from other noncicatricial alopecia with three trichoscopic structures as HH, SRV and CV.     

Successful treatment and prophylaxis of scalp seborrhoeic dermatitis and dandruff with 2% ketoconazole shampoo: results of a multicentre, double-blind, placebo-controlled trial

Pityrosporum ovale appears to play an important role in the pathogenesis of seborrhoeic dermatitis. Ketoconazole is an antimycotic agent with a high in vitro and in vivo efficacy against P. ovale. We performed a multicentre study to investigate the efficacy of ketoconazole 2% shampoo in the treatment and prophylaxis of seborrhoeic dermatitis and dandruff. Five hundred and seventy-five patients presenting with moderate to severe seborrhoeic dermatitis and dandruff of the scalp were treated with 2% ketoconazole shampoo twice weekly for 2–4 weeks, producing an excellent response in 88%. Of those patients who responded, 312 were included in a prophylactic phase, lasting 6 months. These patients were treated with the active preparation (shampoo containing 2% ketoconazole) once-weekly, once every other week, alternating with placebo (shampoo without ketoconazole), or with placebo only once-weekly. Forty-eight (47%) patients in the placebo group experienced a relapse of seborrhoeic dermatitis, compared with 23 (19%) patients in the active treatment group, and 31 (31%) patients in the active/placebo group. The medication was well tolerated in all three groups. We conclude that ketoconazole 2% shampoo is highly effective, not only in clearing scalp seborrhoeic dermatitis and dandruff, but also in preventing relapse of the disease when used prophylactically once weekly.     

Dandruff has an altered stratum corneum ultrastructure that is improved with zinc pyrithione shampoo

Transmission electron microscopy of scalp tape strips indicates that dandruff scalp possesses abnormal stratum corneum (SC) ultrastructure that is normalized by treatment with small-particle zinc pyrithione (ZPT). Similar abnormalities occur throughout the scalp of those with dandruff, even where no flaking is present. SC abnormalities are consistent with hyperproliferation, including parakeratosis, lipid droplets within corneocytes, few desmosomes, corneocyte membrane interdigitation, and excessive disorganized intercellular lipid. Reversal of SC abnormalities would require treatment of the cause(s) of dandruff, not merely flake removal. A protocol was developed to quantify scalp structural abnormalities by scoring cells from scalp tape strips for yeast number, amount of intercellular lipid, normal intercellular lipid structures, prevalence of intracellular lipid droplets, parakeratotic corneocytes, and corneocyte interdigitation. This protocol was used to compare dandruff and normal SC to dandruff SC treated with either commercial ZPT-containing shampoo or a placebo. Treatment with commercial ZPT shampoo significantly returned SC ultrastructure to normal, suggesting control of the cause of dandruff.     

Rosacea and seborrheic dermatitis differentially respond to lactic acid sting and capsaicin tests in Chinese women

Background

Although rosacea and seborrheic dermatitis share some symptoms of sensitive skin, whether they respond differently to lactic acid sting and capsaicin tests, common tests for diagnosis of sensitive skin, is unknown.

Objectives

To reveal the cutaneous responses to lactic acid sting (LAST) and capsaicin test (CAT) in females with either rosacea vs. seborrheic dermatitis.

Methods

A total of 60 patients with rosacea, 20 patients with seborrheic dermatitis and 40 normal controls were enrolled in the study. Their skin sensitivity to stimuli were evaluated following topical application of either 10% lactic acid solution or 0.001% capsaicin solution. Transepidermal water loss (TEWL) rates and erythema indexes were also measured on the face.

Results

In comparison to normal controls, the positive rate to either LAST or CAT was significantly higher in subjects with rosacea (p < 0.001), but not in that with seborrheic dermatitis. Similarly, individuals with rosacea displayed a higher positive rate to both LAST and CAT than those with seborrheic dermatitis and normal controls (p < 0.001). In parallel, the LAST scores and CAT scores in individuals with rosacea were significantly higher than in that with either seborrheic dermatitis or normal controls (p < 0.001). The baseline TEWL rates and erythema indexes were higher in individual with rosacea than in normal controls (p < 0.001). But the baseline TEWL rates and erythema indexes did not differ significantly between subjects with rosacea and that with seborrheic dermatitis. Moreover, LAST scores and CAT scores correlated positively with TEWL (p < 0.0001). TEWL rates were higher in CAT positive than in CAT negative subjects (p < 0.0001). Finally, erythema index correlated positively with CAT scores (p < 0.0001), but not with LAST scores (p = 0.0842).

Conclusions

Skin responses to LAST and CAT differ between individuals with rosacea and those with seborrheic dermatitis, possibly due to the differences in epidermal permeability barrier and the neurovascular hyperreactivity. The higher LAST and CAT scores, as well as positive rates of both LAST and CAT can be attributable to inferior permeability barrier and the neurovascular hyperreactivity in subjects with rosacea.     

Scalp seborrheic dermatitis: prevalence and associated factors in male adolescents

Background The prevalence of seborrheic dermatitis (SD) in the general population is variable in the literature. Factors associated with SD are not well understood. Objective To verify the prevalence of scalp SD in a selected survey of male adolescents on mandatory military service and to find possible associated factors (skin color, socioeconomic level, triceps skin fold, acne, and tobacco consumption). Methods This cross‐sectional study included 18‐year‐old male adolescents on compulsory military service in a southern Brazilian city. Scalp SD was considered as erythema and scaling in any part of the scalp. Skin color, socioeconomic level, triceps skin fold, acne, and tabagism comprised the independent variables studied in our population. Results A total of 2201 adolescents entered the study. The global prevalence of scalp SD was 11%. White skin [adjusted prevalence ratio (PR) 1.42; 95% CI 1.06–1.92; P = 0.02] and triceps skin fold >19.5 mm (adjusted PR 1.56; 95% CI 1.12–2.18; P = 0.009) were significantly associated with scalp SD. The other variables were not associated with the outcome. Conclusions Prevalence of scalp SD in our survey of male adolescents was 11%. The occurrence of scalp SD was associated with white skin and a higher body fat content.     

头皮脂溢性皮炎RCM与皮肤镜特征分析及与头皮银屑病的鉴别

目的总结头皮脂溢性皮炎的反射式共聚焦显微镜(RCM)与皮肤镜特征,并评估二者在鉴别头皮脂溢性皮炎与头皮银屑病的应用价值。方法纳入头皮脂溢性皮炎、头皮银屑病患者各30例,全部行RCM、皮肤镜检查,部分行皮肤组织病理学检查,汇总RCM及皮肤镜各特征的比例,统计诊断两种疾病的敏感度及特异度。结果头皮脂溢性皮炎RCM主要特征为:角化不全、海绵水肿、血管水平扩张、真皮炎细胞浸润、毛囊角栓;其中海绵水肿(灵敏度100.00%、特异度83.33%)及血管水平扩张(灵敏度90.00%、特异度86.67%)对于诊断有较高灵敏度及特异度;该病主要皮肤镜特征为:黄红色背景、分支状血管、非典型血管、血管灶性分布、黄色鳞屑、无结构区、蜂窝状色素网;蜂窝状色素网(灵敏度90.00%、特异度100.00%)、分支状血管(灵敏度90.00%、特异度90.00%)、无结构区(灵敏度86.67%、特异度93.33%)有较高的灵敏度及特异度。对鉴别头皮脂溢性皮炎与头皮银屑病有意义的RCM特征为:海绵水肿、血管水平扩张、毛囊内角栓、角化过度、Munro微脓肿、真皮乳头上移、真皮乳头扩张(P<0.05);有鉴别价值的皮肤镜特征:背景颜色(黄红色、亮红色)、血管分布(灶性、一致性)、血管形态(分支状、非典型及点状、小球状、发夹状、环状血管)、附加特征[鳞屑(黄色、白色)、无结构区、蜂窝状色素网]。结论头皮脂溢性皮炎具有相对独特的RCM及皮肤镜特征,RCM及皮肤镜在头皮脂溢性皮炎及头皮银屑病的鉴别中具有很大的应用价值。     

Factor analysis approach unveils the influencing factors of dandruff in the normal teenage population

The aim of this study was to explore the main factors affecting the occurrence of dandruff in healthy people (nondisease‐induced scalp desquamation). This study analyzed the fungal microbial diversity of the scalp in Chinese teenage volunteers and measured scalp sebum secretion, the scalp pH value, and scalp transepidermal water loss. The amount and size of dandruff were measured, and the main factors that influence dandruff in the normal population were identified using principal component analysis. The results showed that an increase in Malassezia restricta led to an increased amount of dandruff in the mild and moderate groups. Conversely, this was not found for individuals in the severe group, whose dandruff symptoms were influenced by scalp barrier function. In terms of dandruff area grouping, the pH value and the amount of sebum secretion were the main factors, with the barrier function and microbial diversity being secondary factors. Dandruff cosmetics should emphasize different treatments for different types of dandruff to achieve better antidandruff effects. The results of this study provide a new theoretical basis for the development of multiple targets for antidandruff agents aimed at the normal population.     

Demonstration of neutrophil chemotactic anaphylatoxins in human dandruff

Summary In contrast to scales collected from the scalps of nine healthy individuals where a few parakeratotic cells are observable, a large number of parakeratotic cells associated with some infiltrated polymorphonuclear leukocytes (PMNLs) were found in the scales obtained from 11 individuals complaining of dandruff. Therefore, we determined the neutrophil chemotactic properties of the water-soluble extracts of dandruff scales and normal control scalp scales. Aqeous extracts fractionated by Sephadex G-75 showed a potent chemotactic activity only in the fractions of the dandruff patients that eluted with cytochrome C marker (cyt C; molecular weight, 12 kDa). It was comparatively stable to heat but was greatly inhibited by the addition of anti-C5 antiserum. Radioimmunoassay demonstrated that, although small amounts of C5a and C4a anaphylatoxins were demonstratable even in the extracts of normal scalp, they were found in significantly increased amounts in the extracts of dandruff. Moreover, there was a significantly positive correlation between C5a and C4a concentrations in these extracts. These results suggest that classical complement pathway activation with resultant production of C5a anaphylatoxin is involved in the migration of PMNLs into the lesional skin of dandruff.