Pruebas epicutáneas en pacientes con eczema perianal / Patch Testing in Patients With Perianal Eczema

INTRODUCCIÓN Y OBJETIVOS: La prevalencia de parches positivos en los pacientes afectados por una dermatitis anogenital oscila según las series entre un 25-78%, justificándose por tanto la realización de pruebas epicutáneas ante eczemas de esta localización. Los objetivos del presente estudio son por un lado determinar los alérgenos más frecuentes en los pacientes con eczema perianal y, por otro, establecer las baterías de alérgenos más útiles para el estudio con pruebas epicutáneas de esta afección. MATERIAL Y MÉTODOS: Se han revisado retrospectivamente (años 2001-2012) los resultados obtenidos al estudiar con pruebas epicutáneas a aquellos pacientes que presentaban exclusivamente un eczema perianal. RESULTADOS: De los 37 pacientes con esta clínica en 16 se observó alguna reacción positiva, siendo el metilcloroisotiazolinona/metilisotiazolinona el principal alérgeno implicado. Excepto un caso con sensibilización a gentamicina, todas las positividades con relevancia presente correspondieron a alérgenos de la batería estándar del Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea (GEIDAC) o a productos propios del paciente. CONCLUSIONES: En nuestra experiencia la metilcloroisotiazolinona/metilisotiazolinona es el principal alérgeno implicado en los eczemas perianales, procediendo esta sensibilización frecuentemente del uso de toallitas higiénicas. El estudio epicutáneo de un eczema perianal deberá realizarse básicamente con la batería estándar y los productos propios

INTRODUCTION AND OBJECTIVES: Reports show that between 25% and 78% of patients with anogenital dermatitis have positive patch test results. Consequently, patch testing would appear to be warranted in patients presenting with eczema in the anogenital region. The objectives of the present study were to identify the most common allergens in patients with perianal eczema and to determine which allergen series are most useful for patch testing in patients with this condition. MATERIAL AND METHODS: We performed a retrospective review of patch test results in patients with only perianal eczema between 2001 and 2012. RESULTS: Of the 37 patients with perianal eczema, 16 had a positive reaction; methylchloroisothiazolinone/methylisothiazolinone was the main allergen involved. With the exception of 1 case of sensitization to gentamicin, all the positive results with present relevance were to allergens from the standard series of the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) or to the patient's own products. CONCLUSIONS: In our experience, methylchloroisothiazolinone/methylisothiazolinone is the main allergen involved in perianal eczema, and sensitization often results from using wet wipes. Patch testing in perianal eczema should be based on the GEIDAC standard series and the patient's own products

Sialic acids and antimicrobial substances in the apocrine glands of porcine perianal skin.

The porcine perianal skin shows prominent apocrine glands with large saccular dilatations, whereby the functional significance of the glandular secretions is rather unexplained. Our study focuses on the demonstration of sialoglycoconjugates and antimicrobial substances in these glands, using glycoconjugate histochemical and immunohistochemical methods. The result obtained emphasized the general presence of sialic acids, linked to α2-6Gal/GalNAc and α2-3Gaßl1-4GlcNAc, in the secretory cells. The secretory epithelium and luminal secretions also contained a spectrum of antimicrobial substances, such as lysozyme, IgA, lactoferrin, and the peptide group of ß-defensins. Realizing that sialic acids possess diverging functional properties through various saccharide residues, and that antimicrobial substances serve as a non-specific defense against microorganisms, these secretory products may function as protective agents in order to preserve the integrity of the perianal region. This view includes that the amounts of bacteria on the skin surface are controlled and maintained at the certain level.

Antimicrobial chemicals in hoopoe preen secretions are produced by symbiotic bacteria.

Animals frequently use metabolites produced by symbiotic bacteria as agents against pathogens and parasites. Secretions from the preen gland of birds are used for this purpose, although its chemicals apparently are produced by the birds themselves. European hoopoes Upupa epops and green woodhoopoes Phoeniculus purpureus harbour symbiotic bacteria in the uropygial gland that might be partly responsible for the chemical composition of secretions. Here we investigate the antimicrobial activity of the volatile fraction of chemicals in hoopoe preen secretions, and, by means of experimental antibiotic injections, test whether symbiotic bacteria living within the uropygial gland are responsible for their production. Hoopoes produce two different kinds of secretions that differ drastically in their chemical composition. While the malodorous dark secretions produced by nestlings included a complex mix of volatiles, these chemicals did not appear in white secretions produced by non-nesting birds. All volatiles detected showed strong antibacterial activity, and a mixture of the chemicals at the concentrations measured in nestling glands inhibited the growth of all bacterial strains assayed. We found support for the hypothesized role of bacteria in the production of such antimicrobial chemicals because experimental clearance of bacteria from glands of nestlings with antibiotics resulted in secretions without most of the volatiles detected in control individuals. Thus, the presence of symbiotic bacteria in the uropygial gland provides hoopoes with potent antimicrobials for topical use.

Correlation of Propionibacterium acnes populations with the presence of triglycerides on nonhuman skin.

The skins of mice, rats, rabbits, sheep, guinea pigs, and dogs were cultured for Propionibacterium acnes. Only the sebaceous regions (perianal gland) of guinea pigs harbored a significant P. acnes population. Analysis of the lipid from this region revealed a significant percentage of triglycerides, compounds lacking in the sebum of the other animals.