Cow's milk allergy: a critical review.

Foods which are ingested frequently, and cow's milk in particular, are a common cause of delayed-in-onset allergy. Difficulty in diagnosing milk allergy is encountered because: (1) skin tests are unreliable; (2) the symptoms of milk allergy are frequently delayed in appearing, thereby obscuring their connection with the previously ingested food; (3) when such symptoms do appear, they often fail to suggest allergy as etiologic; and (4) the offending antigen may be present in a milk product not obviously associated with milk per se such as sherbet or cheese. Contrary to common belief, most milk (and other food) allergy is not reagin (IgE) mediated.

Allergy skin testing of children.

Skin tests are important aids in the management of patients with inhalant allergy. Their usefulness will be increased if these basic principles are kept in mind: (1) Scratch test should be sufficiently deep, (2) Antigen extracts used for intradermal tests should be fresh enough to insure their activity, (3) Two control tests should be used each time tests are done, (4) Hydroxyzine and promethazine may diminish skin reactivity; therefore, negative skin tests should not be relied upon until repeated in the absence of such medication, and (5) Skin tests for food allergy are quite unreliable, whether positive or negative. Food allergy is best studied by means of elimination trial diets.