The Association of Race/Ethnicity and Patch Test Results: North American Contact Dermatitis Group, 1998-2006.

BACKGROUND: The North American Contact Dermatitis Group patch tests patients with suspected allergic contact dermatitis (ACD) to a broad series of screening allergens and publishes periodic reports. We have previously reported on the association of race and ethnicity with the rates of positive responses to standard patch test allergens. This report extends those observations. OBJECTIVE: The aim of the study was to report the North American Contact Dermatitis Group patch testing results from January 1, 1998, to December 31, 2006, comparing the frequency of positive reactions between white and black subjects. METHODS AND MATERIALS: Standardized patch testing with 45 allergens was used at 13 centers in North America. χ analysis of results in black subjects as compared with whites was examined. RESULTS: A total of 19,457 patients were tested; 92.9% (17,803) were white and 7.1% (1,360) were black. The final diagnoses of ACD (whites, 45.9%; blacks, 43.6%) and irritant contact dermatitis (13.0%/13.3%) were similar in the 2 groups. The diagnosis of atopic dermatitis was less common in the white patients (8.9%) as compared with the black patients (13.3%). Positive patch test reactions rates were similar for most allergens. However, statistically, blacks reacted more frequently to p-phenylenediamine (7.0% vs 4.4%, P < 0.001), bacitracin (11.6% vs 8.3%, P = 0.0004), as well as specific rubber accelerators mercaptobenzothiazole (2.7% vs 1.8%), thiuram (6.2% vs 4.3%), and mercapto mix (1.9% vs 0.8%, P < 0.001). Whites had an increase in positive reactions to fragrances (12.12% vs 6.77%, P < 0.0001), formaldehyde (9.25% vs 5.45%, P < 0.0001), and some formaldehyde releaser preservatives used in personal care products and textile resins (9.80% vs 6.18%, P < 0.0001). CONCLUSIONS: There were statistically different rates of positive patch test reactions to specific allergens between black and white patients suspected of having ACD. The etiology of these differences is unclear but probably relates to culturally determined exposure patterns rather than genetic differences.

Contact irritant dermatitis in Kenya.

Kenya is one of the British Army's main training areas outside of the UK and the flora and fauna present the physicians with several challenges. A 22 year old infantry soldier presented with a vesicular, linear painful rash across his chest caused by the chemical excreted from the Staphylinid or rove beetle, known locally as the Nairobi fly. Treatment included topical antibiotic and steroid creams to good effect. This report highlights the recognition, treatment and complications of the Nairobi Fly.

Self-treatment with bleach by a Latino farmworker.

Skin disease is common among migrant Latino farmworkers. These workers rarely use formal health care services but commonly engage in self-treatment of their skin disease. We present a patient with dermatitis who self-treated with bleach. This patient illustrates a common practice that exacerbates skin disease and sheds light on social and cultural factors of which health care providers serving this community should be aware.

Influence of usage practices, ethnicity and climate on the skin compatibility of sanitary pads.

Modern disposable sanitary pads are becoming available worldwide. Regional differences in usage practices, ethnicity, and climate may influence their skin compatibility. Pad usage practices depend on culture, economics, and menstrual physiology. Daily usage is higher in Japan and but lower in Nigeria compared to North America or Western Europe. Evidence for ethnic differences in skin irritant susceptibility is not compelling. Dark skin may be less susceptible to certain irritants than fair skin; the Japanese may experience a higher degree of sensory irritation than Caucasians. Ambient conditions such as high temperature and humidity increase the skin temperature and skin surface moisture under sanitary pads by small but measurable amounts, causing no discernible skin irritation; vapor-permeable pad backings reduce these effects. Cold dry conditions, which can irritate exposed skin, may not affect vulvar skin to the same degree due to its elevated hydration and occlusion. To address the practical significance of these variables, results of prospective clinical trials of sanitary pads performed by industry and academic scientists in North America (Indiana), Mexico, Western Europe (Munich, Athens, Goteborg, Sweden), Eastern Europe (Kiev) and Africa (Abuja, Nigeria) were reviewed. Despite the diverse range of conditions, no significant adverse skin effects were observed with modern pads compared to traditional pad designs. Study participants generally preferred modern pads for performance and comfort.

Noninvasive evaluation of allergic and irritant contact dermatitis by in vivo reflectance confocal microscopy.

BACKGROUND: The clinical differentiation of allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) is often difficult to accomplish. Reflectance-mode confocal microscopy (RCM) is an imaging technique that has previously been used to examine ACD and ICD noninvasively in vivo. OBJECTIVE: To determine characteristic features of ACD and ICD and their kinetic evolution over time. Ethnic susceptibility to contact irritants such as sodium lauryl sulfate and Ivory dishwashing liquid was evaluated noninvasively, and the sensitivity and specificity of RCM parameters were analyzed in a clinical context and in reference to patch testing. METHODS: Subjects were patch-tested with allergens, irritants, and controls. Clinical scoring and RCM evaluation were performed at various time points, assessing stratum corneum (SC) disruption, spongiosis, exocytosis, vesicle formation, and epidermal thickness. RESULTS: RCM features of both ACD and ICD include spongiosis, exocytosis, vesicle formation, and blood vessel dilatation. SC disruption, epidermal necrosis, and hyperproliferation are hallmarks of ICD whereas ACD more typically presents with vesicle formation. Patients with ICD showed a more rapid recovery than those with ACD. When tested with Ivory soap at selected concentrations, Caucasians, when compared to African Americans, showed significantly lower clinical thresholds for ICD and features that were more severe. CONCLUSIONS: RCM may be a promising new technology for longitudinal noninvasive studies of contact dermatitis (CD). Using a diagnostic algorithm and those parameters with high sensitivity for CD, RCM may facilitate the differentiation of acute ACD and ICD. RCM can reliably visualize cutaneous changes at subclinical degrees of CD, which suggests a possible role for RCM as an adjunctive tool in CD diagnosis. The results of this pilot study also indicate ethnic differences in the response to contact irritants. However, further studies are needed to substantiate the relevance and clinical applicability of our findings.

Irritant contact dermatitis induced by a common household irritant: a noninvasive evaluation of ethnic variability in skin response.

OBJECTIVE: This study was undertaken to investigate the ethnic susceptibility to irritant contact dermatitis induced by a common dishwashing liquid using noninvasive technologies. METHODS: A total of 30 participants (15 Caucasian, 15 African American) were patch tested to graded concentrations of a common household irritant and evaluated using clinical scoring, reflectance confocal microscopy, transepidermal water loss, and fluorescence excitation spectroscopy. RESULTS: At 24 hours, the concentration thresholds for clinically perceptible irritancy were significantly higher for African American compared with Caucasian participants. Reflectance confocal microscopy showed stratum corneum disruption, parakeratosis, and spongiosis; these features were more severe in Caucasian participants (P < or = .002). Mean values for transepidermal water loss were significantly higher in the Caucasian group at comparable clinical scores (P < or = .005). Fluorescence excitation spectroscopy showed a broad excitation band at 300 nm (emission 340 nm) and values in both groups returned to baseline by day 7. LIMITATIONS: This pilot study was limited in scope and larger studies are needed to further evaluate ethnic differences in irritant contact dermatitis and to demonstrate the applicability of our findings for other irritants. CONCLUSION: Clinical evaluation, reflectance confocal microscopy, and transepidermal water loss showed significant differences in the cutaneous irritant response between both groups suggesting a superior barrier function of African American skin. Fluorescence excitation spectroscopy on the other hand demonstrated no differences in the hyperproliferative response after irritant exposure and indicated similar kinetics for the two groups.

The effect of race and ethnicity on patch test results.

BACKGROUND: Allergic contact dermatitis is a condition that may be affected by differences in genetic and environmental factors. Race and ethnicity are possible examples of the former. OBJECTIVE: The objective of this study was to examine the differences in patch test results between white and black individuals tested by the members of the North American Contact Dermatitis Group from July 1, 1992, to June 30, 1998. METHODS: Patients evaluated in our patch test clinics were exposed to a standardized patch testing technique involving a standard series of 41 allergens in total. The standard series we used varied over the 6 years of the study in 2-year cycles. The series was the same at all centers during each of these 2-year cycles: 1992-94, 1994-96, and 1996-98. Over a 6-year period, our group tested 9624 patients. Of those individuals, 8610 (89.5%) were white and 1014 (10.5%) were black. RESULTS: Allergic contact dermatitis and irritant contact dermatitis were the final diagnoses assigned by the investigators to individuals of the 2 races: 49% and 16%, respectively, for the white patients and 46% and 15%, respectively, for the black patients. In at least one of the three 2-year periods, testing in white patients revealed higher rates of sensitization to formaldehyde, glutaraldehyde, and a number of the formaldehyde-releasing preservatives, as well as lanolin, epoxy resin, thioureas, and balsam of Peru. Black patients exhibited higher rates of sensitization to para-phenylenediamine, cobalt chloride, thioureas, and p-tert-butylphenol formaldehyde resin in at least one of the 2-year periods. CONCLUSION: In this test population, we found no differences in the overall response rate to allergens. There were some differences between white and black patients in their response to specific allergens. These differences, although possibly related to genetic factors based on race, are more likely related to differences in allergen exposure determined by ethnicity.