Epicutaneous sensitization. what do we know?

Background. According to the currently existing hypothesis, epicutaneous sensitization is one of the leading mechanisms in the development of food allergy.The aim of this review was to analyze immune mechanisms in epicutaneous sensitization and the role of skin barrier impairment.We performed a literature search using PubMed, UpToDate, Web of Science, and Scopus databases by the key words: epicutaneous sensitization, atopic dermatitis, skin barrier impairment, food allergy. Articles were to be in open access and present the most relevant information on the topic. Studies were selected by the largest sample size and the highest citation index. Once publications were identified, they were reviewed by all the authors to select the studies that specifically addressed the theme of the review. A total of 101 publications from 1998–2000 were included in the study.This review article discusses the data of experimental studies, sets out modern ideas about the hypothesis of a double exposure to an allergen, and presents research data proving the clinical significance of epicutaneous sensitization in relation to food allergy. Knowledge about the mechanisms of epicutaneous sensitization development is necessary to elaborate strategies for prevention of food allergy. One of the modern trends in prevention is the use of emollients, which are supposed to restore the skin response. However, studies on preventive intake of emollients do not present a similar viewpoint.There is not enough evidence for or against the mechanism of epicutaneous sensitization as an indispensable condition for the formation of food allergies. Further research in this area is required.

Sensitization with Eustrongylides sp. (Nematoda: Dioctophymatidae) antigens induce production of specific IgG and IgE in murine model

Fish consumption plays an important role in human diet. Hoplias malabaricus, commonly known as traíra, is a freshwater fish widely appreciated in several Brazilian states and frequently infected by Eustrongylides sp. fourth-instar larvae (L4). The aim of the present study was to evaluate allergenic potential of Eustrongylides sp. L4 crude extract (CEE). BALB/c mice were immunized intraperitoneally (IP) by 10 μg CEE with 2 mg of aluminum hydroxide on days 0 and 35. Specific IgG and IgE antibody levels were determined after immunization and cellular immunity was evaluated by assessing intradermal reaction in ear pavilion. Epicutaneous sensitization was performed in dorsal region by antigen exposure using a Finn-type chamber containing 50 μg of CEE or saline solution, followed by evaluation of specific antibody levels. IP immunization resulted in a gradual increase in IgG antibody levels and transitory IgE production. Significant increase in ear thickness was observed in cellular hypersensitivity reaction. In case of antigen exposure by epicutaneous route, CEE was able to induce meaningfully increased levels of specific IgG and IgE antibodies as well as heightened cellular immunity. Both intraperitoneal immunization and epicutaneous contact with Eustrongylides sp. larval antigens were observed for first time to be capable of inducing immunological sensitization in mice.