Skin prick test predictive value on the outcome of a first known egg exposure in milk-allergic children

Children with milk allergy have higher incidence of other food allergies, especially egg allergy. The objective of this study was to ascertain the accuracy of the prick test in children with IgE-mediated milk allergy for diagnosing egg allergy. Children under the age of 1 yr who came consecutively to Allergy Department 2003–05, and were diagnosed with IgE-mediated milk allergy were selected for this study. Egg introduction was completely avoided until the age of 14 months when clinical history, skin prick tests (SPT), specific-IgE antibodies determination and egg challenge test were performed. One hundred and four milk-allergic children were included. At least one positive prick test to any egg allergen was found in 65 out of the 104 (62.5%). Thirty-eight (36.5%) were allergic to egg proteins as well. Prick tests with egg white and ovomucoid (OVM) had the best diagnostic performances showing the largest areas under the receiver operating characteristic curve. The optimal diagnosis cut-off point was 6 mm for egg white and 5 mm for OVM. The positive likelihood ratios for these cut-off points were: 2.95 (95% CI: 1.74–4.99) for egg white prick test, and 20 (95% CI: 2.9–143.7) for OVM prick test. Children with specific IgE-mediated cow's milk allergy must be closely followed as a risk group for egg allergy. Early diagnosis is necessary and the SPT has shown itself to be a very useful tool for diagnosing immediate IgE reactions to egg on first known exposure.     

The spectrum of cow''s milk allergy

Childhood cow's milk allergy is a diagnosis encompassing various syndromes. Antigen-immunoglobulin E (IgE) antibody interaction is classically involved in mast cell degranulation in IgE-mediated food allergy, while non-IgE mediated cow's milk allergy is mostly mediated by cellular mechanisms. The diagnosis of cow's milk allergy largely relies on a good knowledge of the clinical expression of the disease. In this educational review series, we describe three cases of cow's milk allergy, first a 7-yr-old girl with persisting IgE-mediated cow's milk allergy, second a 8-month-old boy with cow's milk induced flares of atopic dermatitis, and third a 6-yr-old boy with sheep and goat milk allergy, in the absence of cow's milk allergy. The cases are discussed and summarized with more general recommendations for the clinical management of cow's milk allergy.     

Anaphylactic reaction to goat's milk in a cow's milk-allergic infant

Goat's milk has been used as a substitute for cow's milk in cow's milk-allergic individuals. It is currently advocated for this purpose in writings and internet resources directed at the lay person, and infant formula based on goat's milk is available in many countries. Clinically significant cross-allergenicity between cow's and goat's milk has been noted, but a life-threatening cross-reaction has not been reported. We describe a 4-month-old infant with immunologically documented cow's milk protein allergy but no prior exposure to goat's milk who developed anaphylaxis after the ingestion of commercial goat's milk. Subsequent skin prick testing demonstrated a specific reaction to goat's milk. Thus, the cross-allergenicity between cow's and goat's milk proteins can lead to life-threatening complications. Individuals allergic to cow's milk protein should avoid goat's milk and goat's milk products.     

Anaphylaxis to sheep's milk cheese in a child unaffected by cow's milk protein allergy

A 5-year-old atopic boy unaffected by cow's milk protein allergy experienced several anaphylactic reactions after eating food containing “pecorino” cheese made from sheep's milk. Prick-prick tests were strongly positive to sheep's buttermilk curd and `pecorino' sheep's cheese. Skin prick tests to fresh sheep's milk and to goat's milk were also positive, whereas they were negative to all cow's milk proteins, to whole pasteurized cow's milk and to cheese made from cow's milk. Specific IgE antibodies were negative to all cow's milk proteins. Conclusion Sheep's milk and cheese derived from sheep's milk may cause severe allergic reactions in children affected and, as we report, in children not affected by cow's milk protein allergy. Received: 14 January 1997 and in revised form: 20 June 1997 / Accepted: 8 July 1997     

Natural history of IgE-mediated food allergy in fully breast-fed babies

We have studied 21 babies with IgE-mediated food allergy (FA) sensitized via breast milk. The diagnosis of IgE-mediated FA was based on the response to elimination diet and challenge tests, and was confirmed by positive RAST and skin tests. The children exhibited immediate symptoms, such as urticaria, angioedema, and asthma. Only 5/21 children developed tolerance to the offending food at the median age of 14 years. The children who failed to develop tolerance still have high levels of IgE antibodies towards the offending food. In conclusion, the results of our long-term follow-up study show that the natural history of FA in children sensitized via breast milk may be less optimistic than generally reported.     

Association of HLA-DQ7 antigen with cow milk protein allergy in Italian children

In this study we investigated the HLA association with cow milk allergy. Thirty-seven Italian children with cow milk allergy and 35 randomly selected age-matched healthy children as control group were included in the study. DNA typing was performed by restriction fragment length polymorphism (RFLP) technique. We show the first statistically significant positive association between the expression of the HLA-DQ7 antigen and cow milk allergy. Several immunological tests (skin prick test, RIA, radioallergosorb-ent test (RAST) and ELISA) were performed to evaluate the humoral immune responses of DQ7 positive and DQ7 negative allergic patients. Our results show that among the DQ7 positive patients the majority presented a high humoral response. Furthermore, the in vitro proliferative response of patients to the †-lactoglobulin antigen was performed to evaluate their cell-mediated immune response. We observed that the number of the nonre-sponders was higher in the DQ7 positive patients when compared to the DQ7 negative patients.
Our data indicate an association of HLA-DQ7 antigen with cow milk pro tein allergy and that the DQ7 positive patients had a prevalence of humoral rather than cellular responses.     

Specific oral tolerance induction in childhood

Food allergy continues to be a significant public health concern for which there are no approved treatments and management strategies primarily include allergen avoidance and pharmacological measures for accidental exposures. Food allergy is thought to result from either a failure to establish oral tolerance or the breakdown of existing oral tolerance, and therefore, experimental preventative and treatment strategies are now aimed at inducing specific oral tolerance. This may occur in infancy prior to the development of food allergy through the optimal timing of dietary exposure (primary oral tolerance induction) or as a treatment for established food allergy through oral immunotherapy (secondary oral tolerance induction). Trials examining the effectiveness of early dietary allergen exposure to prevent food allergy have yielded promising results for peanut allergy but not so for other allergens, although the results of several trials are yet to be published. Although infant feeding guidelines no longer advise to avoid allergenic foods and exposure to food allergens orally is an important step in inducing food tolerance by the immune system, evidence regarding the optimal timing, dose and form of these foods into the infant's diet is lacking. Likewise, oral immunotherapy trials appear promising for inducing desensitization; however, the long‐term efficacy in achieving sustained desensitization and optimal protocols to achieve this is unknown. More research is needed in this emerging field.     

Efficacy of donkey's milk in treating highly problematic cow's milk allergic children: An in vivo and in vitro study

Successful therapy in cow's milk protein allergy rests on completely eliminating cow's milk proteins from the child's diet: it is thus necessary to provide a replacement food. This prospective study investigated tolerance of donkey's milk in a population of 46 selected children with cow's milk protein allergy, for whom it was not possible to use any cow's milk substitute. Thirty-eight children (82.6%) liked and tolerated donkey's milk at the challenge and for the entire duration of follow-up. Catch-up growth was observed in all subjects with growth deficit during cow's milk proteins challenge. The degree of cross-reactivity of immunoglobulin E (IgE) with donkey's milk proteins was very weak and aspecific. Donkey's milk was found to be a valid alternative to both IgE-mediated and non-IgE-mediated cow's milk proteins allergy, including in terms of palatability and weight-height gain.     

Safety of measles immunization in egg-allergic children

Measles vaccines are prepared in chick embryo fibroblast culture and used throughout the world. Since 1963 dramatic reductions in the incidence of measles have been observed where the vaccination was extensively applied in the pediatric population. The best results were observed when the target population in the initial phase was that which produced over 90% of cases in the pre-vaccinal era. A possible limiting factor to the diffusion of measles vaccination is the assumption that allergy to egg proteins is a contraindication. In this paper current knowledge about the safety of measles immunization in children with egg allergy is discussed.     

A FOLLOW-UP STUDY OF INFANTS WITH ADVERSE REACTIONS TO COW'S MILK I. Serum IgE, Skin Test Reactions and RAST in Relation to Clinical Course

Abstract. 47 infants with cow's milk sensitivity were followed for a period varying between 6 months to 4 years (mean 28 months). The age at onset of symptoms varied between 14 days to 20 months. The clinical course was studied in relation to reaginic allergy by use of serum IgE, skin prick test and RAST. Infants with an immediate onset of symptoms from the gastrointestinal tract and the skin after cow's milk intake were discerned as a distinct entity having a high frequency of atopy in the family, positive skin tests and positive RASTs to milk (71%). Cases with delayed reactions to cow's milk seldom had a positive RAST or skin test. Most infants of both groups showed an increasing tolerance to milk. In RAST positive infants the RAST-titers increased significantly after onset of symptoms. After having reached a peak the titers subclined in several cases. The titers did not reflect the degree of milk sensitivity during the follow-up period. However, infants who developed high titers seemed to develop tolerance more slowly than infants with low titers.