American Journal of Contact Dermatitis最新文献

Skin irritation safety testing and risk assessment for new products, and the ingredients they contain, is a critical requirement before market introduction. In the past, much of this skin testing required the use of experimental animals. However, new current best approaches for skin corrosion and skin irritation testing and risk assessment are being defined, obviating the need for animal test methods. Several in vitro skin corrosion test methods have been endorsed after successful validation and are gaining acceptance by regulatory authorities. In vitro test methods for acute, cumulative (repeat exposure), and chronic (prolonged exposure) skin irritation are under development. Though not yet validated, many are being used successfully for testing and risk assessment purposes as documented through an expanding literature. Likewise, a novel acute irritation patch test in human subjects is providing a valid and ethical alternative to animal testing for prediction of chemical skin irritation potential. An array of other human test methods also have been developed and used for the prediction of cumulative/chronic skin irritation and the general skin compatibility of finished products. The development of instrumental methods (e.g., transepidermal water loss, capacitance, and so on) has provided the means for analyzing various biophysical properties of human skin and changes in these properties caused by exposure to irritants. However, these methods do not directly measure skin inflammation. A recently introduced skin surface tape sampling procedure has been shown to detect changes in skin surface cytokine recovery that correlate with inflammatory skin changes associated with chemical irritant exposures or existing dermatitis. It holds promise for more objective quantification of skin irritation events, including subclinical (sensory) irritation, in the future.

Background: Mercury derivatives are frequent contact allergens and their cross-reactivity is not constant. Thimerosal is an organic mercurial used as an antiseptic and as a preservative in most vaccines. Objective: To evaluate cross-reactivity, exposure factors, and tolerance to vaccines containing thimerosal in patients sensitized to mercury derivatives. Methods: Design: Observational study (cross-sectional); Patients: 125 patients were recruited for the study, 72 women and girls and 53 boys and men, average age 18.7 years old, range 3 to 65, with positive patch tests to mercury derivatives and/or thimerosal; Interventions: All patients were studied by means of enquiry, patch tests, intradermal tests, and intramuscular challenge with thimerosal. Results: A sensitization to thimerosal was observed in 57 patients. Twenty-four of these 125 patients presented a positive intradermal reaction. Ammoniated mercury seems to be a good marker of mercury sensitization eliciting positive reaction in 78% of all patients and merbromin in 66%. In most cases, (100/125) cross-reactivity was found among mercury derivatives. The intramuscular injection of thimerosal induced a mild local reaction in only 5 patients (4% of the total, 9% of thimerosal positive reactions). Childhood vaccinations, merbromin used as an antiseptic, broken thermometers, and the use of drops were the main sources of exposure. Conclusions: The majority of the patients showed positive tests to both organic and inorganic mercury derivatives. Vaccination with thimerosal is relatively safe, even for individuals with delayed type hypersensitivity to this chemical, since more than 90% of allergic patients tolerated intramuscular challenge tests with thimerosal. A simplified protocol of patch tests to study mercury derivatives is proposed. It would be advisable to restrict the use of mercurial antiseptics and mercury thermometers.

Background: There is little, if any, literature regarding placing and reading of patch-tests on tattooed skin. Method: A patient whose entire back was covered with multiple tattoos was patch-tested. Results: Multiple positive patch-tests were seen with no apparent reduction in intensity related to tattooed skin. Conclusion: If necessary, patch-tests can be placed and read on tattooed skin

Phenylephrine is widely used as an ophthalmic drug. However, there are only very few reports on allergic contact dermatitis induced by phenylephrine. In addition, little is known on cross reactivity patterns between the sympathomimetics phenylephrine, epinephrine and ephedrine which share a similar chemical structure. We report on a man who developed allergic contact dermatitis to Neosynerphin POS[reg ] eyedrops containing phenylephrine hydrochloride. Cross reactivity between phenylephrine, epinephrine and ephedrine was studied by patch testing. Patch tests were performed with the European standard, an ophthalmics and preservatives series, Neosynerphin POS[reg ] eyedrops, phenylephrine hydrochloride 10% aq., epinephrine and ephedrine (both 1.0 % aq.). Test sites were read after 48, 72 and 168 hours according to the recommendations of the ICDRG. Neosynerphin POS[reg ] and phenylephrine hydrochloride 10 % aq. gave positive reactions, whereas epinephrine and ephedrine tested negative. Although phenylephrine is an epinephrine analog delayed type hypersensitivity to phenylephrine did not result in cross reactivity with chemically related epinephrine and ephedrine.

Background: Temporary black henna tattoos are very popular as body adornment. Although contact allergy to natural henna is unusual, the inclusion of hair dye, p-phenylenediamine (PPD), increases the risk of contact sensitization. Objective: This study was performed to identify the presence and concentration of PPD in a black henna tattoo mixture to which our patient developed contact allergy. Methods: The presence of PPD in a black henna tattoo mixture, various samples of commercially available henna powders, and several hair dye products was qualitatively and quantitatively detected using high performance liquid chromatography (HPLC). Results: This study demonstrated that PPD was present in the black henna tattoo mixture at a concentration of 15.7%, which is significantly higher than commercial hair dye preparations. Conclusion: The presence of PPD in black henna tattoo mixtures in high concentration poses a health hazard and a risk of allergic contact sensitization with potential long-term consequences.

Cocamidopropyl betaine (CAPB) is a surfactant, and reports of allergic contact dermatitis to this chemical have been reported in the literature. Although most commonly found in rinse-off products, the chemical nonetheless has been shown to induce allergy. The actual component responsible for allergic reaction may be the final compound itself, CAPB, or one of the substances used in its synthesis that may be present as an impurity. Allergy to CAPB is most commonly seen in a head and neck distribution, although other patterns have been identified.

Background: Patch testing with a standard allergen series often yields positive reactions to more than 1 allergen in a patient. Objective: To identify all significantly associated pairs of positive reactions and to assess their relation to the strength of the reactions and to the irritative potential of the allergens. Methods: Based on the filed data of 57,822 patients, associations between positive reactions to 2 different allergens were quantified with odds ratios. Statistical methods included Fisher's exact test, the Bonferroni adjustment to account for the effect of multiple testing, and the Spearman rank correlation. Results: Out of the 32,779 patients with complete readings of 24 standard allergens, 7,501 had shown more than 1 positive reaction. Statistically significant associations were detected for 166 out of the 276 possible different combinations of 2 distinct positive reactions, including combinations that had not been identified before. Patients with a strong reaction or a positive reaction to an allergen with a high irritative potential tended to have additional positive reactions to further allergens more often than others, but the number of significant associations was not dependent on these parameters. Conclusion: There are more significant associations that have to be taken into account for patch testing than has been known so far. Although irritation can favor a higher number of positive reactions, significant associations of positive reactions to distinct allergens are probably caused by other mechanisms that require further analyses.

We report a case of combined contact and photocontact allergic dermatitis to etofenamate in Flogoprofen gel (Chiesi Wasserman, Barcelona, Spain). Patch test results were positive at the nonirradiated site, but there was a stronger reaction at the irradiated site with etofenamate 0.05% in petrolatum (pet.) at d2 and d4. The use frequent of topical agents containing etofenamate and sun exposure can result in a predisposition to contact photoallergy. Clinical findings caused by etofenamate are uncommon. Allergic contact dermatitis is the most common cutaneous reaction reported. In American studies observed, no reactions were observed to etofenamate in subjects with photosensitivity because it was not included in the series of antigens used in testing.

A review of the literature has identified 10 agents causing contact dermatitis among topically administered drugs for glaucoma. These agents include [beta ]-blockers (timolol, befunolol, betaxolol, levobunolol, carteolol, metipranolol), a carbonic anhydrase inhibitor (dorzolamide), a parasympathomimetic (pilocarpine), and sympathomimetics (dipivefrin, apraclonidine). Patch testing has been documented in certain individuals as well as cross sensitization and reactivity. Systemic reactions to these topically applied medications have been briefly noted.