Photoallergic Contact Dermatitis to Sunscreens Containing Oxybenzone in La Plata, Argentina. / Dermatitis por contacto fotoalérgica a protectores solares con oxibenzona en La Plata, Argentina.

BACKGROUND: Photoallergic contact dermatitis (PACD) to oxybenzone was reported for the first time in 1980. Oxybenzone is the most common photoallergen in the United States and Canada and the fourth most common .in Europe. There are no studies or data on the prevalence of oxybenzone PACD in Argentina. OBJECTIVE: To determine the proportion of photosensitive patients with PACD to oxybenzone. METHODS: We conducted a descriptive cross-sectional study of 35 patients with photosensitivity reactions confirmed by photopatch testing at the Research Center of Hospital Público San Martín in La Plata, Argentina, in 2015 and 2016. RESULTS: PACD was identified in 6 patients (17.14%). Five of these (14.28%) had at least one positive reaction to oxybenzone in the photopatch test; 4 had a reaction at irradiated sites only (5 J/cm2 UVA) and one had a reaction at both irradiated and nonirradiated sites. CONCLUSIONS: PACD to sunscreens containing oxybenzone is common and is probably underdiagnosed due to a lack of confirmation by photopatch tests or other diagnostic tools. Sensitization rates vary according to region and are influenced by sunscreen ingredients and variations in the use of sunscreen products, cosmetics, and topical drugs.

Fotossensibilização primária em eqüídeos e ruminantes no semi-árido causada por Froelichia humboldtiana (Amaranthaceae) / Primary photosensitization in equidae and ruminants in the Brazilian semi-arid caused by Froelichia humboldtiana (Amaranthaceae)

Fotossensibilização é freqüente em eqüinos no semi-árido da região Nordeste, mas jumentos, mulas, ovinos e bovinos são, também, afetados. A dermatite afeta, principalmente, áreas de pele despigmentadas e os animais se recuperam após serem retirados das pastagens. Para comprovar a etiologia da enfermidade Froelichia humboldtiana (Roem. et Schult.) Seub., coletada no campo foi administrada no mesmo dia da colheita ou após ser mantida em refrigerador por 1-4 dias, por períodos de 30 ou mais dias, ad libitum como único alimento, a 2 jumentos e um ovino branco e, como único alimento volumoso, a um eqüino branco. Esses animais não manifestaram sinais clínicos e as atividades séricas de gama-glutamiltransferase (GGT), aspartato-aminotransferase (AST) e alanino-aminotransferase (ALT) ficaram dentro dos valores normais. Em outro experimento, um ovino foi colocado a pastar diariamente, durante o dia, preso por uma corda em uma área que tinha exclusivamente F. humboldtiana, por um período de 26 dias. Lesões características de fotossensibilização foram observadas 4-5 dias após o início do experimento. Após cessar o consumo da planta, no 26º dia, o ovino recuperou-se totalmente em 30 dias. Em outro experimento, 4 ovinos foram também colocados, presos por cordas, na mesma área. Outros 4 permaneceram como controles em uma pastagem vizinha, mas sem F. humboldtiana. Lesões de pele, características de fotossensibilização foram observadas após 11-25 dias de consumo de F. humboldtiana. As atividades séricas de AST e GGT, e os níveis de bilirrubina sérica permaneceram dentro dos valores normais. No final do período de permanência em pastagens de F. humboldtiana, 2 ovinos foram abatidos e 2 foram retirados da pastagem. Os que foram abatidos não apresentaram lesões macroscópicas nem histológicas do fígado; os outros dois se recuperaram das lesões da pele 17 e 20 dias após o fim do pastejo. Uma égua e seu potro foram colocados na mesma pastagem com F. humboldtiana...(AU)

Photosensitization is common in the Brazilian semiarid, affecting mainly horses, but also donkeys, mules, sheep and cattle. The dermatitis affects mainly non pigmented skin, and the animals recover after being withdrawn from the pastures. To demonstrate the etiology of the disease, Froelichia humboldtiana (Roem. et Schult.) Seub., collected in the field one or two times a week and kept in the refrigerator for 1-4 days, was administered for 30 or more days as the only food ad libitum to 2 donkeys and one white sheep, and as the only forage ad libitum, to one white horse. No clinical signs were observed in those animals, and serum activities of aspartate-aminotransferase (AST), alanine-aminotransferase (AST), and gamma-glutamyltransferase (GGT) were within normal ranges. In another experiment, one sheep was tied by a rope, during the day, in a pasture of exclusively F. humboldtiana for a 26 days period. Skin lesions characteristic of photosensitization appeared 4-5 days after the start of the experiment and became severe until day 26. After the withdrawal of the animal from the pasture on day 26 it fully recovered within 30 days. In another experiment, 4 sheep were tied by ropes in the same pasture, during the day, for a 29 days period. Another 4 control sheep were maintained in a neighboring pasture without F. humboldtiana. Skin lesions characteristic of photosensitization were observed after 11-25 days of F. humboldtiana grazing. Serum activities of AST and GGT, and serum levels of bilirubin were within normal ranges. At the end of the 29 days grazing F. humboldtiana, 2 sheep were euthanized, and 2 were withdrawn from the pastures. No gross or histologic liver lesions were observed on the 2 sheep euthanized; the other 2 sheep recovered within 17 and 20 days after the end of grazing. One mare and its foal grazed in the same pasture during 44 days. The mare that had a pigmented skin had no dermatitis, but the foal showed dermatitis on the...(AU)

Fotossensibilização primária em eqüídeos e ruminantes no semi-árido causada por Froelichia humboldtiana (Amaranthaceae) / Primary photosensitization in equidae and ruminants in the Brazilian semi-arid caused by Froelichia humboldtiana (Amaranthaceae)

Fotossensibilização é freqüente em eqüinos no semi-árido da região Nordeste, mas jumentos, mulas, ovinos e bovinos são, também, afetados. A dermatite afeta, principalmente, áreas de pele despigmentadas e os animais se recuperam após serem retirados das pastagens. Para comprovar a etiologia da enfermidade Froelichia humboldtiana (Roem. et Schult.) Seub., coletada no campo foi administrada no mesmo dia da colheita ou após ser mantida em refrigerador por 1-4 dias, por períodos de 30 ou mais dias, ad libitum como único alimento, a 2 jumentos e um ovino branco e, como único alimento volumoso, a um eqüino branco. Esses animais não manifestaram sinais clínicos e as atividades séricas de gama-glutamiltransferase (GGT), aspartato-aminotransferase (AST) e alanino-aminotransferase (ALT) ficaram dentro dos valores normais. Em outro experimento, um ovino foi colocado a pastar diariamente, durante o dia, preso por uma corda em uma área que tinha exclusivamente F. humboldtiana, por um período de 26 dias. Lesões características de fotossensibilização foram observadas 4-5 dias após o início do experimento. Após cessar o consumo da planta, no 26º dia, o ovino recuperou-se totalmente em 30 dias. Em outro experimento, 4 ovinos foram também colocados, presos por cordas, na mesma área. Outros 4 permaneceram como controles em uma pastagem vizinha, mas sem F. humboldtiana. Lesões de pele, características de fotossensibilização foram observadas após 11-25 dias de consumo de F. humboldtiana. As atividades séricas de AST e GGT, e os níveis de bilirrubina sérica permaneceram dentro dos valores normais. No final do período de permanência em pastagens de F. humboldtiana, 2 ovinos foram abatidos e 2 foram retirados da pastagem. Os que foram abatidos não apresentaram lesões macroscópicas nem histológicas do fígado; os outros dois se recuperaram das lesões da pele 17 e 20 dias após o fim do pastejo. Uma égua e seu potro foram colocados na mesma pastagem com F. humboldtiana...

Photosensitization is common in the Brazilian semiarid, affecting mainly horses, but also donkeys, mules, sheep and cattle. The dermatitis affects mainly non pigmented skin, and the animals recover after being withdrawn from the pastures. To demonstrate the etiology of the disease, Froelichia humboldtiana (Roem. et Schult.) Seub., collected in the field one or two times a week and kept in the refrigerator for 1-4 days, was administered for 30 or more days as the only food ad libitum to 2 donkeys and one white sheep, and as the only forage ad libitum, to one white horse. No clinical signs were observed in those animals, and serum activities of aspartate-aminotransferase (AST), alanine-aminotransferase (AST), and gamma-glutamyltransferase (GGT) were within normal ranges. In another experiment, one sheep was tied by a rope, during the day, in a pasture of exclusively F. humboldtiana for a 26 days period. Skin lesions characteristic of photosensitization appeared 4-5 days after the start of the experiment and became severe until day 26. After the withdrawal of the animal from the pasture on day 26 it fully recovered within 30 days. In another experiment, 4 sheep were tied by ropes in the same pasture, during the day, for a 29 days period. Another 4 control sheep were maintained in a neighboring pasture without F. humboldtiana. Skin lesions characteristic of photosensitization were observed after 11-25 days of F. humboldtiana grazing. Serum activities of AST and GGT, and serum levels of bilirubin were within normal ranges. At the end of the 29 days grazing F. humboldtiana, 2 sheep were euthanized, and 2 were withdrawn from the pastures. No gross or histologic liver lesions were observed on the 2 sheep euthanized; the other 2 sheep recovered within 17 and 20 days after the end of grazing. One mare and its foal grazed in the same pasture during 44 days. The mare that had a pigmented skin had no dermatitis, but the foal showed dermatitis on the...

Causal agents of photoallergic contact dermatitis diagnosed in the national institute of dermatology of Colombia.

OBJECTIVE: To describe and identify the photoallergens causing photoallergic contact dermatitis in the population attending the outpatient clinic of the Centro Dermatologico Federico Lleras Acosta (CDFLLA), the National Institute of Dermatology of Colombia. MATERIALS AND METHODS: Eighty-two patients with clinical diagnosis of photoallergic contact dermatitis enter the study. These patients attended the CDFLLA between August 2001 and May 2003. Photopatch tests were performed using the standard series of sunscreens (Chemotechnique Diagnostics) and 6-methylcoumarin. Cetyl alcohol, phenoxyethanol, methylparabene, propylene glycol, triethanolamine, propylparabene, trichlorocarbanilide and dichromate were also included. The allergens were applied in duplicate on the healthy skin of the back and covered with opaque tape withdrawn 24 h later, the panel on the right was irradiated with an ultraviolet A dose of 5 J/cm(2). The tests were read 24 h after the application of the allergens, 24 and 72 h post-irradiation. The readings were assessed according to the visual scoring system recommended by the International Contact Dermatitis Research Group. RESULTS: Twenty-six patients (31.7%) showed positive photopatch test responses to one or several allergens. Four of them showed positive results to three components of the series and four patients to two components. Thirty-eight photoallergic and 18 allergic reactions were observed. Ultraviolet filters were the substances which more frequently produced positive photopatch test responses (30.5%). The most common ultraviolet filter photoallergen was benzophenone-3 with 22/82 positive results (26.8%), followed by octyl methoxycinnamate (8/82), benzophenone-4 and mexenone (2/82), phenylbenzimidazole sulphonic acid, methylbenziliden camphor and octyl dimethyl PABA (1/82). One patient showed a photoallergic response to 6-methylcoumarin. There was a concordance between the allergen which elicited the positive response and the use of different substances which contained that molecule among its compounds in 17 patients (65.3%). 19.5% of the patients (16/82) showed positive results to one or several allergens in the irradiated panel as well as in the unirradiated control site. These cases were diagnosed as contact allergy, probably caused by aeroallergens, presenting a natural history and a clinical picture similar to photocontact allergy. The most common allergen was dichromate with 10 positive results. CONCLUSIONS: The results of this study confirm that sunscreens are the more frequently involved substances in photoallergic contact dermatitis in our population. Identification of the photoallergen is the key element for adequate disease control and patient education.