Natural history of immediate-type hen's egg allergy in Japanese children.

BACKGROUND: Hen's egg (HE) allergy develops during infancy. We investigated tolerance acquisition in Japanese children allergic to HE aging <6 years. METHODS: In this retrospective study, 226 children born in 2005 with a history of immediate-type HE allergy underwent an oral food challenge (OFC). Tolerance was defined as no reaction to an OFC with half of whole heated HE or accidental HE consumption at home. Participants were divided into three groups based on age at tolerance acquisition: group I (<3 years) (n = 66), group II (3-6 years) (n = 98), and group III (prolonged allergic groups) (n = 62). RESULTS: Tolerance acquisition occurred in 30% (66/226) by 3 years of age, 59% (133/226) by 5 years of age, and 73% (164/226) at 6 years of age. At 3 years, incidences of allergy-related complications (bronchial asthma, p = 0.02; atopic dermatitis, p = 0.04) were higher in the group III than in the group I. Anaphylaxis to any food occurred more frequently in the group III than in the group I (p = 0.03); anaphylaxis to HE was more common in the group III (p = 0.04). Egg white (EW)- and ovomucoid (OM)-specific immunoglobulin E (IgE) levels were higher in the group III than in the group I (p < 0.05). CONCLUSIONS: The group III experienced HE-related anaphylaxis and complications more frequently and exhibited sustained, high EW- and OM-specific IgE levels.

Immunotherapy in food allergy: towards new strategies.

Allergen avoidance is the standard treatment for managing food allergies. Complete avoidance is difficult, and accidental exposure often occurs. Immunotherapy is a significant focus for treating food allergies, and oral immunotherapy (OIT) appears to be particularly effective in inducing desensitization. The majority of patients who receive OIT show increased threshold doses of their food allergen. The efficacy of OIT is different among food antigen, and milk OIT is relatively difficult to achieve tolerance. OIT may induce mild to moderate symptoms during the therapy, widespread acceptance of OIT for long-term therapy is unclear. Recently, novel immunotherapies for food allergies, such as sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT) and using an anti-IgE monoclonal antibody (omalizumab), have been assessed. In addition, a combination of OIT with omalizumab, which was found to increase the threshold doses of the offending foods without producing adverse reactions, may be effective and useful in the treatment of food allergies. These treatments have been used only in research settings; further studies in large numbers of patients are needed to demonstrate their long-term safety and benefits in clinical practice.

Clinical studies in oral allergen-specific immunotherapy: differences among allergens.

Oral immunotherapy (OIT) is a significant focus of treatment of food allergy. OIT appears to be effective in inducing desensitization, however, patients receiving OIT frequently developmild/moderate symptoms during the therapy. It has not been clearly established whether the clinical tolerance induced by OIT resembles natural tolerance. According to our data, the efficacy of OIT is different among food antigens, and it is comparatively difficult to achieve the clinical tolerance in milk OIT. Moreover, the definitive evidence of efficacy and safety with long-term therapy is limited. Further studies need to be offered to patients in clinical practice. Recently, novel treatments for food allergy, sublingual and epicutaneous immunotherapy, and combination treatment with an anti-IgE monoclonal antibody (omalizumab), have been examined in some studies. OIT combined with omalizumab increased the threshold doses of food without adverse reactions and may be of benefit in food allergy treatment. More studies are needed to demonstrate long-term safety and treatment benefits in a larger patient cohort.

[Association between childhood oral allergy syndrome and sensitization against four major pollens (Japanese cedar, orchard grass, short ragweed, alder)].

BACKGROUND/AIM: Although OAS (oral allergy syndrome) during childhood is believed to be rare, it seems to be increasing these days. METHODS, SUBJECTS: We here report 16 cases of childhood OAS, which were diagnosed, in our division. In addition to these reports, we investigated the rate of sensitization against four major pollens (Japanese cedar, orchard grass, short ragweed, alder) among 1067 pediatric patients with allergic diseases (median age: 4 years old) in our division. The sensitization was examined by IgE CAPRAST and above class 2 was judged as positive sensitization. RESULTS: OAS in childhood differs from that in adulthood in some ways. One is that childhood OAS does not always accompany with pollinosis. The most frequent allergen in our study was kiwi fruits followed by tomato, orange and melon among these patients. The sensitization rate against alder was equivalent as that against orchard grass and short ragweed, but less than that against Japanese cedar. CONCLUSION: Childhood OAS may have different mechanisms from adulthood OAS which almost always accompanies with pollinosis or latex allergy.

[Feature of food allergy developed during infancy (2)--acquisition of tolerance against hen's egg, cow's milk, wheat, and soybean up to 3 years old].

BACKGROUND: Once food elimination is introduced, it is important to know for doctors when patients generally develop oral tolerance against eliminated food. To clarify the point, following study was conducted. METHODS: We analyzed 304 patient profiles with food allergy in our division between 1994 and 2001. The diagnosis of oral tolerance was determined by the results of food challenges or the accidental episodes of ingestion. RESULTS: By the age of 3 years old, 78% of food allergy patients with soybean, 63% of those with wheat, 60% of those with cow's milk, 51% of those with egg yolk, and 31% of those with egg white developed oral tolerance, respectively. IgE CAP RAST scores against cow's milk, egg yolk, and egg white in the patients without tolerance were significantly higher than those in the patients with tolerance. CONCLUSION: Patients developed oral tolerance firstly against soybean followed by wheat, cow's milk, egg yolk and egg white during the first 3 years of life. The specific IgE antibody levels against egg and cow's milk are important for the diagnosis of tolerance.

[Feature of food allergy developed during infancy (1)--relationship between infantile atopic dermatitis and food allergy].

BACKGROUND: Most of food allergy (FA) cases during childhood start as infantile atopic dermatitis (AD) at the ages of a few months old. We tried to clarify the association between infantile AD and FA during infancy. METHODS: We analyzed relationship between AD and FA during infancy among patients with 208 cases, who had visited our outpatient clinic with chief complaint of "eczema" from 1998 to 2000. RESULTS: Among 208 cases, 148 cases (71%) were diagnosed as infantile AD, moreover 109 cases (74%) were diagnosed as FA among infantile AD. The most frequent food antigens among infantile AD were egg (72.3%), cow's milk (39.9%), wheat (12.2%) and soybean (7.4%), respectively, in addition to these food antigens, food allergy was widely recognized against peanuts, sesame, meats, buckwheat, fishes and potato. In terms of food antigen, 44 cases with single food allergy against egg were seen out of 46 single allergy cases, whereas 36 cases with double food allergy against both egg and cow's milk were seen in 63 multiple food allergy cases. Although the value of antigen specific IgE against egg and cow's milk was recognized for the diagnosis of food allergy during infancy, even cases with negative IgE against those foods were proved to be food allergy by food elimination and provocation tests. In contrast to egg and cow's milk, positive IgE against rice, soybean, and wheat did not always correlate with the results of the diagnosis of food allergy. Concerning risk factors of AD, family history of any allergy diseases and passive smoking were recognized in comparison with infantile eczema. Neither the nutrition method nor incomplete elimination of diet during pregnancy and lactation had anything to do with the development of AD. CONCLUSION: When infantile AD cases were not improved by environmental control, skin care and application of steroid ointment, it would be important for doctors to think of the possibility of FA.