Regional and seasonal differences in skin irritation and neurosensitivity in Chinese and South Korean women.

BACKGROUND: China has a great variety of geographical and climatic conditions, and several cultural differences exist within the country; thus, understanding the regional and seasonal differences that cause skin sensitivities in this country is important. OBJECTIVE: The aim of this study was to assess skin sensitivity of women from six cities in China and from South Korea during the winter and summer seasons to aid the development of suitable and effective dermatological products. METHODS: This multicentre study included 754 healthy female volunteers, and was conducted in the winter (between January and March) and summer (between June and July) of 2011. Patch tests were performed using 0.5% sodium lauryl sulphate (SLS) aqueous solution and 0.15% retinol in 1,3-butylene glycol on the back of the volunteers. Simultaneously, stinging tests were performed on their cheeks by using 5% lactic acid solution and 0.001% capsaicin solution, each in a negative control vehicle (distilled water and 10% ethanol solution, respectively). RESULTS: The patch test results showed that the subjects in Beijing and Shenyang were more sensitive to SLS, retinol and lactic acid in the winter than were those in Guangzhou, Shanghai, Wuhan, Chengdu and South Korea. The stinging test results revealed that the subjects in Beijing were more neurosensitive to lactic acid in the winter; however, during the same season, the subjects from Shanghai and Guangzhou were significantly more neurosensitive to capsaicin. CONCLUSION: Our observations indicate that skin sensitivity differs considerably between women from different parts of China and South Korea. We recommend that these differences be considered during the development of cosmetic products in these countries.

Ethnic differences in objective and subjective skin irritation response: an international study.

BACKGROUND: Due to global marketing in the cosmetics industry, it is important to assess ethnic population susceptibility when evaluating the safety of cosmetic products or chemicals. OBJECTIVES: To investigate ethnic variations in skin irritation response to positive irritants. METHODS: Clinical testing was performed in four countries on two ethnic groups - Asian and Caucasian. We performed patch tests on the subjects' back with 0.5% aqueous sodium lauryl sulfate (SLS) and 0.15% retinol prepared in 1,3-butylene glycol. Stinging tests were performed using 5% aqueous lactic acid and 0.001% (w/v) capsaicin prepared in 10% ethanol solution separately. RESULTS: The incidence of self-perceived skin sensitivity was similar in the two ethnic groups. However, the incidence of adverse skin reaction to cosmetics appeared significantly higher in Asian (33.0%) than in Caucasian subjects (11.3%). For standard positive irritants such as 0.5% aqueous SLS solution, Asian subjects showed significantly higher scores than Caucasian subjects. The incidence of positive reaction to the 0.15% retinol patch test tended to be higher in Asian than in Caucasian subjects. Our data also showed that neurosensitivity to 5% lactic acid and 0.001% capsaicin was higher in Asian than in Caucasian subjects. CONCLUSION: Although self-reported skin sensitivity does not appear to differ according to ethnicity, there are ethnic differences in objective and subjective skin irritation responses to several standard positive materials.

How do perceptions of sensitive skin differ at different anatomical sites? An epidemiological study.

BACKGROUND: People with sensitive skin vary not only in the signs and symptoms they experience, but also in the degree of sensitivity at different anatomical sites. AIM: To determine patterns of perceived sensitive skin using an epidemiological approach among a general population, evaluating the results for ethnic, gender and age differences. METHODS: Questionnaires designed to evaluate perceptions of sensitive skin in general and at specific body sites (face, body and genital area) were given to 1039 people. Respondents were not selected based on any criteria related to sensitive skin, but consisted of people participating in other studies on consumer products. RESULTS: Of the study population, 68.4% claimed their skin was sensitive to some degree, 77.3% claimed sensitive facial skin, 60.7% claimed sensitive body skin and 56.3% claimed sensitive skin in the genital area. There were no significant gender, ethnic or age differences, except in the genital area; a higher percentage of women and African Americans claimed sensitive skin in this area. CONCLUSIONS: The prevalence of perceived sensitive skin was higher in this study than in previous reports. Individuals had different perceptions about the degree of sensitivity at different anatomical sites.

Common dermatologic disorders in skin of color: a comparative practice survey.

There is a paucity of data on the epidemiology of dermatologic disease in populations with skin of color. Our objective was to compare the most common diagnoses for which patients of various racial and ethnic groups were treated at a hospital-based dermatology faculty practice. We reviewed the diagnosis codes of 1412 patient visits from August 2004 through July 2005 at the Skin of Color Center at St. Luke's-Roosevelt Hospital Center, in New York. New York, in whom race and ethnicity were recorded. The most common diagnoses observed during dermatologic visits by black and white patients were compared. The leading diagnoses observed during the study period differed between black and white patients. During visits by black patients, the 5 most common diagnoses observed at our center were acne (ICD-9 [International Classification of Diseases, Ninth Revision] 706.1); dyschromia (ICD-9 709.09); contact dermatitis and other eczema, unspecified cause (ICD-9 692.9); alopecia (ICD-9 704.0); and seborrheic dermatitis (ICD-9 690.1). During visits by white patients, the 5 most common diagnoses recorded were acne (ICD-9 706.1); lesion of unspecified behavior (ICD-9 238.2); benign neoplasm of skin of trunk (ICD-9 216.5); contact dermatitis and other eczema, unspecified cause (ICD-9 692.9); and psoriasis (ICD-9 696. 1). Although similarities were seen in the frequency of acne and eczema, conditions such as dyschromia and alopecia were commonly seen during black patient visits but were not among the leading 10 diagnoses made during white patient visits.

Differences of skin irritation between Japanese and European women.

BACKGROUND: After using cosmetics, Japanese women frequently complain about sensitive, stinging skin. We wondered whether Japanese women's skin is more sensitive than that of Caucasians. OBJECTIVES: To examine possible racial differences of skin irritation and subjective sensations. METHODS: We performed patch testing on the forearm with sodium lauryl sulphate (SLS) at different concentrations (0.25%, 0.5%) and 24-h exposure time. Skin reaction was evaluated by measurement of transepidermal water loss (TEWL), stratum corneum hydration, sebum secretion, laser Doppler flowmetry (LD), content of melanin and erythema. During a stinging test with 10% lactic acid (applied to one side of the cheeks) the subjects were asked to describe the present intensity of any sensation. We used a Chromameter to measure skin colour before and after application of lactic acid. This study was performed in Marburg, Germany, with healthy Japanese and German women living in Marburg. RESULTS: After SLS testing, we found no significant differences of the barrier function in the stratum corneum, but we found significant subjective sensory differences between Japanese and German women. CONCLUSIONS: Japanese women may complain about stronger sensations reflecting a different cultural behaviour rather than measurable differences in skin physiology; however, a faster penetration of SLS in Japanese cannot be excluded.

Ethnic variations in self-perceived sensitive skin: epidemiological survey.

To examine possible ethnic variations in perception of sensitive skin, an epidemiological survey was performed in the San Francisco area. Approximately 800 telephone interviews were conducted with women from four different ethnic groups (Afro-Americans, Asians, Euro-Americans, Hispanics; approximately 200 women per group). In addition to sensitive facial skin assessments, age and other general skin condition data were collected. 52% of the subjects identified themselves as having sensitive facial skin. There was no statistical difference between the ethnic groups in terms of sensitive skin prevalence. Nevertheless, some differences were noted between ethnic subgroups of sensitive skin. Euro-Americans were characterized by a higher skin reactivity to wind and tended to be less reactive to cosmetics. Afro-Americans presented diminished skin reactivity to most environmental factors and a lower frequency of recurring facial redness. Asians appeared to have greater skin reactivity to spicy food, to sudden changes in temperature and to wind, and tended to suffer from itching more frequently. Hispanics presented a lower incidence of skin reactivity to alcohol. The differences in skin sensitivity between ethnic groups concerned mostly factors of skin reactivity and, to a lesser extent, its symptomatology. But, taken together, we note the similarities in comparing how women of varying ethnic backgrounds perceive the sensitive skin condition.

Evacuation of an Aboriginal community in response to an outbreak of blistering dermatitis induced by a beetle (Paederus australis).

OBJECTIVE: To describe an outbreak of dermatitis induced by the beetle Paederus australis and the public health measures implemented to control it. SETTING: A remote Aboriginal community in the Northern Territory of Australia. METHODS: Inspection of the community and interviews with residents to document skin lesions, sleeping locations and beetle activity. Samples of the beetle were collected for identification. RESULTS: The community was affected by a plague of beetles. All 40 residents reported painful, blistering, skin lesions. Four required hospitalisation for treatment of an extensive exfoliating and ulcerating dermatitis. The community was evacuated to allow skin lesions to heal and the beetle plague to decline. CONCLUSION: This is the first reported en masse outbreak of Paederus dermatitis in Australia. Paederus dermatitis should be considered as a differential diagnosis of vesicular dermatitis in tropical Australia.

Changing trends in the epidemiology of contact dermatitis in Singapore.

All patients seen in the Contact Dermatitis Clinic of the National Skin Centre, Singapore (and the former Middle Road Hospital) between January 1986 and December 1990 were analysed retrospectively. 5557 patients comprising 2634 (47.4%) males and 2923 (52.6%) females were patch tested. 3154 (56.8%) patients had 1 or more positive reactions. The majority of the patients were Chinese (78.0%), followed by Malays (11.5%), Indians (8.1%) and other minority races (2.4%). The majority of positive reactions belonged to the 21-40 age group. The incidence of positivity decreased after 60 years. The commonest allergens responsible were nickel (17.7%), fragrance (13.3%), neomycin (6.9%), colophony (6.6%) and proflavine (6.5%). Both neomycin and proflavine were commonly used as over-the-counter medicaments. Compared to an earlier report in 1988, there were differences in the incidence of contact sensitivity to some allergens. Potassium dichromate, which used to be a common allergen, was less common. Some allergens (carba-mix, naphthyl-mix, caine-mix and PCMX) have been removed from our standard series as they were uncommon causes of contact allergy. Thimerosal and Amerchol L-101 were added in their place.

Cosmetics in blacks.

Blacks comprise a phenotypically heterogeneous group with respect to skin and hair. They are uniquely multihued with at least 35 different possible shades of pigmentation, and there is considerable variability in hair texture. This accounts for many of the unique skin and hair cosmetic requirements and customs in the black race. These grooming practices may present perplexing problems for the dermatologist when viewed in the context of resultant skin disease; therefore, an awareness and understanding of skin and hair products used by blacks, grooming techniques, and their consequences are essential for clinicians caring for black patients.

Sensitive and ethnic skin. A need for special skin-care agents?

Sensitive skin is a complex problem with genetic, individual, environmental, occupational, and ethnic implications. Further work is needed to rank irritants and irritant reactions to classify sensitive skin on the basis of standard models. The development of topical products designed for sensitive and ethnic skin may be advisable to optimize drug activity with minimal side effects. The availability of transdermal systems for drug delivery highlights the problem. Occlusive transdermal patch systems for delivery of clonidine show sensitization rates of 34% in white women, 18% in white men, 14% in black women, and 8% in black men. Besides ethnic differences in transcutaneous penetration, individual and ethnic skin sensitivity may play an important role in determining both patient compliance and therapeutic efficacy of drugs and cosmetics; furthermore, a drug formulation considering skin physiology may prevent unwanted local and general adverse effects.

Toxicological study of the molluscicidal latex of Euphorbia splendens: irritant action on skin and eye

Aqueous solutions of the molluscicidal latex of Euphorbia splendens are irritant to the rabbit eye in concentrations higher than 0.35% and to the rabbit skin in concentrations higher than 0.5%. Although this irritant potential does not proclude its use as a molluscicide, special precautions are recommended for hanbdling and application of the product and the hazard of skin tumor-promoting potencial should be carefully investigated before its use for schistosomiasis vector control.

Factors predisposing to cutaneous irritation.

In experimental skin toxicology, as well as in clinical practice, considerable interindividual variation in the susceptibility to irritant dermatitis is noted when irritant doses are low. Cutaneous sensitivity and hypersensitivity are not determined by a single known feature but are multifactorial. Previous atopic dermatitis may predispose to irritant dermatitis. Susceptibility to irritation seems to be influenced by age, race, and genetic background, whereas sex-related differences do not seem to exist. Of biophysical skin baseline features, skin-surface pH was correlated with the severity of experimentally induced irritant dermatitis, but baseline transepidermal water loss, water-holding capacity, stratum corneum turnover time, and sebum content were not.

Contact sensitivity to topical medicaments.

Of patients patch tested at a contact dermatitis clinic between 1985 and 1986, 22.5% (379/1685) had medicament sensitivity. The prevalence in men was 22.8% (193/847) and in women, 22.1% (186/838) (difference not significant). The rate appears to increase with age, 17.9% (216/1205) for patients less than 40 years old and 34.0% (163/480) for patients over 39 years old (difference, p less than 0.001). The differences in prevalence between Chinese (22.8%), Malay (21.3%), Indians (20.4%), and others (33.3%) were not statistically significant. Common sensitizers included neomycin (7.8%), proflavine (7.1%), clioquinol (4.3%), colophony (3.3%), and wool alcohol (2.7%). Proflavine sensitivity was significantly more common in men (9.9%) than women (4.2%) (p less than 0.001). Most dermatitis occurs on the limbs (upper limbs, 44.3%; lower limbs, 43.0%). Facial dermatitis was more common in women (37.4%) than men (19.2%) (difference not significant).

Contact dermatitis in blacks.

Black skin is characterized by structural and functional differences such as increased stratum corneum cohesion, melanin content, and stratum corneum layers. These differences seem to make black skin difficult for irritants and light to penetrate, thus explaining the common opinion that skin in blacks is harder and develops contact dermatitis less frequently. The paucity of interpretable epidemiologic data and of clinical and experimental studies does not permit confirmation of this hypothesis, and the few data available are controversial. This article describes the main physiologic differences between black and white barrier function and reviews the literature on irritation, sensitization, and transcutaneous penetration. We found that the data are still too incomplete to generalize on the resistance, or lack thereof, of black skin (versus white skin) to chemical irritation, sensitization, and penetration.

The usefulness of detailed information to patients with contact allergy.

To find out if patients with contact allergy are helped by computerized information lists, a retrospective study was carried out on 58 patients with contact allergy to lanolin, traced through our local database DALUK. All were sent a questionnaire about their usage of the information list, clearance of their eczema, their education and other details. Clearance of the patient's eczema was found to correlate with use of the information list. It was also found that the effectiveness of the information depended on factors such as education, family circumstances, ethnic background and, most of all, how and where the information list was used.