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Biomedical subjects

S A Bock

Publications and source records attributed to S A Bock.

48 records · Page 3Linked to original sources

The natural history of food sensitivity.

The natural history of food sensitivity has long been the subject of anecdotes about children "outgrowing" their problem, but prospective systematic studies are not easily found that document these opinions. Children who had had adverse reactions to foods during double-blind food challenges 1 to 7 yr prior to this study were evaluated. In children over 3 yr of age, 19% of the previously positive food challenges were negative at the time of the follow-up; in children 3 yr of age or younger, 44% of the food challenges that had been positive were negative. The data collected thus far suggest that children who have their food sensitivity diagnosed at older ages tend not to outgrow the problem. Skin testing was performed over a period of years on some of the subjects, and skin sensitization was found to be markedly persistent, even in subjects who could consume the sensitizing food without symptoms.

Aging↗

Evaluation of a patient with both aquagenic and cholinergic urticaria.

An 11-yr-old girl presented with a history of urticaria induced by warm or cool showers, exercise, and emotional stimuli. During evaluation she repeatedly developed generalized punctate urticaria, pruritus, palpitations, and headaches after warm baths or exercise, and she had a positive methacholine skin test. She developed similar lesions and pruritus after local application of sterile water, tap water, ethanol, normal saline, or 3% saline. The diagnosis of combined aquagenic and cholinergic urticaria was made and presented a unique opportunity to study and compare mediator release and clinical symptoms in both conditions. The patient was submerged in bath water at either 37 degree or 41 degree C to induce either aquagenic or cholinergic urticaria, respectively. Histamine was released into the systemic circulation in both conditions in a similar time course; however, systemic symptoms occurred only after the 41 degree C bath. After failure to induce tolerance to the 41 degree C bath water, hydroxyzine therapy was instituted. One week later she was rechallenged; few symptoms appeared, and a rise in serum histamine was not detected as had been shown in previous challenges. The data suggest that in our patient, hydroxyzine may have contributed to the inhibition of both histamine release and the appearance of symptoms during hot bath challenging.

Anxiety↗

Usefulness of measurement of antibodies in serum in diagnosis of sensitivity to cow milk and soy proteins in early childhood.

A noteworthy feature of this study is that comparisons were made between specific, sensitive, quantitative measurements of serum antibodies to food proteins and objective appraisal of clinical manifestations by double-blind food challenges. Over 50 children, 4-30 months of age, with suspicious histories of adverse reactions to cow milk or soy products were investigated. Levels of serum antibodies to cow-milk proteins were clearly higher in children with adverse reactions to milk, confirmed by blind challenge; there was no overlap with the lower levels of serum antibodies in children without confirmed reactions. Findings with serial determinations of serum antibodies to cow milk in selected cases are also presented. The levels of serum antibodies evoked by cow milk and soy formulae fed from birth until 4 months of age were similar. The levels of serum antibodies to soy protein in children with and without adverse reactions to soy products were not definitive. The bearing of these data on the comparative "antigenicity" of cow milk and soy products and the distinction between asymptomatic and clinically significant, symptomatic, sensitivity are discussed.

Animals↗

Studies of hypersensitivity reactions to foods in infants and children.

In order to extend previous investigations of adverse reactions to foods performed at this institution, 68 children, aged 5 mo to 15 yr, were studied. All subjects reported a history of adverse reaction to ingestion of one or more of the 14 foods under study. Sixteen of 43 subjects, 3 yr of age or older, had 22 adverse reactions during 94 food challenges with one or more of the 14 foods. All reactions confirmed were to peanut or other nuts, milk, egg, and soy. Skin testing with 1:20 weight/volume concentrations of food extracts applied by the puncture technique produced a net wheal reaction 3 mm or greater in all subjects 3 yr of age or older in whom double-blind food challenges confirmed the history of adverse reaction. Thirteen of 25 children less than 3 yr of age manifested adverse reactions during 49 food challenges. Skin testing by puncture technique produced a net wheal 3 mm or greater in 9 children less than 3 yr of age in whom food challenge elicited a clinical response within 2 hr. One of 4 subjects less than 3 yr of age in whom the adverse reaction occurred more than 4 hr after food challenge exhibited a wheal to puncture skin test of 3 mm or greater. These studies suggest that at present double-blind food challenge is an indispensible tool for the unequivocal evaluation of adverse reactions to foods.

Adolescent↗

Appraisal of skin tests with food extracts for diagnosis of food hypersensitivity.

Seventy-six children aged 5 months to 15 years who exhibited a net weal of 3.0 mm or greater to a puncture skin test with one or more of fourteen foods were subjected to double-blind food challenge. Confirmed reactions to double-blind food challenge were found to occur only with peanut, milk, egg and soybean. Puncture skin tests with 1:20 w/v concentration of food extracts identified all subjects who exhibited an adverse reaction during the double-blind food challenge. Performance of intradermal skin tests did not identify any additional subjects who reacted clinically to double-blind food challenge.

Adolescent↗

Proper use of skin tests with food extracts in diagnosis of hypersensitivity to food in children.

This study was undertaken to determine the proper use of skin tests with food extracts in diagnosis of hypersensitivity to food in children. Cutaneous reactions evoked by graded amounts of food extracts were compared with results of double-blind food challenge and in vitro release of histamine from leucocytes. A 3 mm or greater weal reaction in skin tests by puncture technique using food extracts of 1:20 w/v concentration was found to indicate the degree of hypersensitivity likely to be associated with clinically significant hypersensitivity reactions to food. Proper use of this simple technique will facilitate accurate diagnosis of food hypersensitivity in children by identifying the group among whom all positive reactions to food challenges will be found. Nevertheless, double-blind food challenge is essential to establish a diagnosis of symptomatic hypersensitivity to food.

Adolescent↗

A study of serum antibodies to isolated milk proteins and ovalbumin in infants and children.

Serum antibodies to cow milk proteins and ovalbumin were measured quantitatively. Food hypersensitivity of the immediate type was determined to be present or absent by skin tests and double-blind food challenges. Elevated levels of antibodies to milk proteins in sera characteristic of infants fed cow milk were found to decline with age, so that sera from children who were 6 to 15 years of age (inclusive), not hypersensitive to food, had significantly lower levels than the infants. In contrast, sera from age-matched children, who were shown to have hypersensitivity to some food, were found to have levels of antibodies to milk proteins as elevated as in infancy. Hypersensitivity was not necessarily to milk but often to some other food. This persistence of greater antibody production to milk throughout childhood in those hypersensitive to some food indicates a fundamental difference from those without hypersensitivity to food, either in permeability, in immunological reactivity of the gut or in development of immunological unresponsiveness. Implications for pathogenesis of clinical disorders are discussed.

Adolescent↗

The natural history of adverse reactions to foods.

The studies presented and the literature reviewed support the conclusion that the natural history of food sensitivity is a dynamic process. Thus foods removed from the diet must be reintroduced at regular intervals. Adverse reactions to foods probably involve multiple immunologic and inflammatory mechanisms and cannot always be pigeon-holed into a specific Type I-IV reaction. As in all areas of our field, it is important to continue our search for ways to identify the exceptional patient who requires measures which do not fit the usual situation. There will always be patients with exceptional problems requiring special arrangements that we as allergists must be prepared to evaluate. However, it is reassuring to see that over a period of time the majority of patients continue to have their problems successfully evaluated by methods which are currently available.

Child Development↗