Outcome of food intake and nutritional status after discontinuation of a cow’s-milk-free diet post negative oral food challenge in infants and children

Objective: To evaluate the outcome of food intake and nutritional status post discontinuation of a cow’s-milk-free diet after a negative oral food challenge.Methods: This was a prospective, uncontrolled study that evaluated food intake and nutritional status of a cohort of 80 infants and children under 5 years of age. Food intake and nutritional status were evaluated on the day of the oral food challenge test and after 30 days. Weight and height were measured on the day of the test and after 30 days.Results: The mean age of the patients was 18.7 ± 12.4 months, and 58.7% were male. After discontinuation of the elimination diet, the children showed daily intake increases in (P < 0.001), protein (P < 0.001), carbohydrates (P = 0.042), calcium from foods (P < 0.001), calcium from foods and supplements (P < 0.001), phosphorus (P < 0.001), and vitamin D from foods (P = 0.006). The Z-scores (n = 76) on the day of the oral food challenge test and 30 days after restarting the consumption of cow’s milk were as follows: weight-for-age (P < 0.001) and height-for-age (P < 0.001), respectively.Conclusion: Cow’s milk protein in the diet was associated with increased intake of energy, proteins, carbohydrates, calcium, phosphorus, and vitamin D, in addition to an increase in the Z-scores for weight-for-age and height-for-age.

Threshold of Reactivity and Tolerance to Precautionary Allergen-Labelled Biscuits of Baked Milk- and Egg-Allergic Children

Extremely sensitive food-allergic patients may react to very small amounts of allergenic foods. Precautionary allergen labelling (PAL) warns from possible allergenic contaminations. We evaluated by oral food challenge the reactivity to a brand of PAL-labelled milk- and egg-free biscuits of children with severe milk and egg allergy. We explored the ability of proteomic methods to identify minute amounts of milk/egg allergens in such biscuits. Traces of milk and/or egg allergens in biscuits were measured by two different liquid-chromatography-mass spectrometry methods. The binding of patient’s serum with egg/milk proteins was assessed using immunoblotting. None of the patients reacted to biscuits. Egg and milk proteins were undetectable with a limit of detection of 0.6 µg/g for milk and egg (method A), and of 0.1 and 0.3 µg /g for milk and egg, respectively (method B). The immunoblots did not show milk/egg proteins in the studied biscuits. Milk/egg content of the biscuits is far lower than 4 µg of milk or egg protein per gram of product, the minimal doses considered theoretically capable of causing reactions. With high sensitivity, proteomic assessments predict the harmlessness of very small amount of allergens in foods, and can be used to help avoiding unnecessary PAL.

Milk and cow’s meat allergy in a child: A clinical case

Allergy to bovine serum albumin is the main predictor of beef allergy associated with cow’s milk proteins allergy. We report a case of a 3-year-old child with cow’s milk proteins allergy since the age of 6 months who, after some ingestions of beef, developed episodes of irritability, urticaria and syncope. Specific IgE to beef, oral food challenge with medium rare cooked beef and specific IgE to bovine serum albumin were all positive, but an oral food challenge with well cooked beef was tolerated. Allergy to bovine serum albumin is not usually associated with severe reactions, since it is a thermolabile protein, however, the process of cooking meat may be insufficient to have an effect on the complex matrix of meat and associated serum albumins. The irregular pattern of the episodes and the previous diagnosis of cow’s milk proteins allergy may act as confounding factors leading to a delayed diagnosis.

Threshold of Reactivity and Tolerance to Precautionary Allergen-Labelled Biscuits of Baked Milk- And Egg-Allergic Children

Extremely sensitive food-allergic patients may react to very small amounts of allergenic foods. Precautionary allergen labelling (PAL) warns from possible allergenic contaminations. We explored the ability of proteomic methods to identify minute amounts of milk/egg allergens in a brand of PAL-labelled milk- and egg-free biscuits. We evaluated the reactivity of children with severe milk and egg allergy, by oral food challenge. Traces of milk and/or egg allergens in biscuits were measured by two different liquid-chromatography-mass spectrometry methods. The binding of patient's serum with egg/milk proteins was assessed at immunoblotting. None of the patients reacted to biscuits. Egg and milk proteins were found under the limit of detection of 0.6 &micro;g/g for milk and egg (method A), and of 0.1 and 0.3 &micro;g /g for milk and egg, respectively (method B). The immunoblots did not show milk/egg proteins in the studied biscuits. Our biscuits did not contain allergens of clinical significance. Their milk/egg content is far lower than 4 &micro;g of milk or egg protein per gram of product, the minimal doses considered theoretically capable of causing reactions. With high sensitivity, proteomic assessments predict the harmlessness of very small amount of allergenic foods and can be used to avoid unnecessary PAL.

Detection of Salivary Tryptase Levels in Children following Oral Food Challenges

<b><i>Background:</i></b> Oral food challenge (OFC) is commonly used to diagnose food allergy. This test is time and resource intensive, and conclusions are not always unequivocal as this relies on the interpretation of symptoms. Therefore, an objective marker would improve the accuracy of the diagnostic workup of food allergy. <b><i>Objectives:</i></b> The aim of this study was to investigate whether tryptase can be detected in saliva of children following OFC. <b><i>Method:</i></b> Children from 3 to 18 years of age were eligible for inclusion if an OFC for peanut or tree nut had been recommended. Saliva samples were collected prior to the first dose and 5, 10, and 15 min following the last administered dose during OFC. Assay precision, spike-and-recovery, and assessment of lower limit of detection of the tryptase immunoassay were examined before analysis of tryptase in saliva was performed. <b><i>Results:</i></b> A total of 30 children were included (median age 8 years, 63.3% male, 53.3% positive OFC outcome). Tryptase was detected in saliva samples. The mean of the change in baseline tryptase value to each saliva collecting time point was significantly different in patients with a positive OFC outcome compared to a negative outcome (<i>p</i> &#x3c; 0.01). <b><i>Conclusions:</i></b> This study showed that tryptase can be detected in saliva of children following OFC. Increased levels of tryptase compared to baseline were found if the OFC outcome was positive, suggesting that measuring tryptase in saliva may be useful in the diagnosis of food allergy. Further research is needed to evaluate the potential association between tryptase levels and symptoms.