Search

Environmental exposure to food allergens may be a risk factor for cutaneous sensitization. Previous studies could detect peanut allergen in house dust. In this pilot study, we wanted to investigate whether hen's egg allergen is detectable in house dust collected from different household areas and whether levels are increased after intentional hen's egg consumption. Hen's egg protein levels of dust samples were measured using ELISA. In 8 of 8 households, hen's egg was detectable in dust samples of eating area and bed. Forty-eight hours after intentional hen's egg consumption, hen's egg protein levels were significantly increased in both. Still, further research is necessary to investigate whether hen's egg allergen in house and bed dust plays a role in sensitization via skin.

Background Egg-sensitized infants who have never eaten egg may react at first ingestion. We sought to determine the association between skin prick test (SPT) and specific IgE (sIgE) to egg proteins (EP) and oral food challenge (OFC) outcomes to find cut-off points which can diagnose egg allergy. Methods One hundred and fifty-four infants up to 18 months, with cow's milk allergy (CMA) and/or atopic dermatitis (AD) without previous egg consumption, were recruited. SPT to EP were performed. If it was positive, sIgE was performed. If positive SPT and/or sIgE (n = 94), OFC was performed between 12 and 18 months. Receiver operating characteristic (ROC) curves were plotted, and the outcome of the OFC was related to SPT and sIgE. The cut-off points with the best diagnostic accuracy were found. Results Ninety-four patients were sensitized to egg (69%) and 60 nonsensitized (31%). Of the sensitized, 27 tolerated cooked (CE) and raw egg (RE) (28.7%). Sixty-seven were allergic (71.3%): 29 reacted to CE, seven to egg yolk (EY) and 22 to egg white (EW) and 38 reacted to RE. 69.2% tolerated CE. EW SPT and ovalbumin (OVA) sIgE have the best area under the curve (AUC). The higher positive predictive values (PPV) were obtained for EW SPT and EW sIgE. Conclusions In egg-sensitized infants with EW SPT ≥8 mm and/or EW sIgE ≥8.36 KU/l, egg diagnostic OFC can be avoided as there is 94% probability of becoming positive. In the other patients, OFC should be performed safely and early to avoid unnecessary diets.

Purification procedures for the four egg-white proteins ovomucoid, ovotransferrin, ovalbumin, and lysozyme are presented with reference to mechanistic studies at epitope levels of allergic reactions to these proteins. The applied procedures resulted in four preparations containing less than 0.1% contaminating proteins each. The purified protein preparations were characterized by SDS-PAGE and by crossed immunoelectrophoresis with polyclonal antibodies raised against an egg-white extract or the purified proteins. The necessity of these well-characterized proteins in studies on allergic reactions was shown by testing human sera in immunoblots of lysozyme, and by immunoblots of ovomucoid probing with antibodies against the proteins.

An egg protein, lysozyme, is a still unlabeled additive currently used in cheese preparation. Furthermore, the WHO-FAO committee considers it innocuous. However, 31% of children and 8% of adults with food allergies are allergic to eggs. This work aimed to determine the percentage of patients sensitized to lysozyme from a population of egg-allergic patients. Specific IgE was determined with Cap RAST in 52 patients clinically allergic to egg. Thirty-five percent of egg-allergic patients had antilysozyme IgE. Given this high incidence of lysosozyme sensitization, it seems that the presence of lysozyme should be indicated on food labels.

We have studied the hypersensitivity to hen's egg protein and chicken meat in 25 adults with a previous diagnosis of bronchial asthma and rhinoconjunctivitis due to bird feather sensitization. Seventeen of the 25 reported good tolerance to the ingestion of egg and chicken meat. The skin tests were negative to both antigens in 15 of them, and positive for egg in two. All 17 patients had negative RAST to chicken meat and egg protein. The remaining eight patients had intolerance to egg, and three of them also to chicken meat ingestion; in seven of the eight cases allergic to egg, the alimentary intolerance began after the clinical symptoms of bird feather sensitization. In all eight cases the skin tests were positive to egg yolk, and in five of them also to egg white and chicken meat. These patients evidenced specific serum IgE antibodies to egg yolk, four of them to egg white, and seven to chicken meat. These results demonstrate the high frequency (32%) of the association of sensitization to egg proteins, particularly egg yolk, in a selected population of patients with known allergy to bird feathers, thus suggesting that in some patients feather sensitization could trigger or somehow facilitate the later sensitization to egg yolk proteins.