Roberta Onesimo, MD, Valentina Giorgio, MD, Stefania Pili, MD, Serena Monaco, MD and Stefano Miceli Sopo, MD
Fish is a common cause of food allergy. The reactions usually occur after its ingestion. In most immunoglobulin E-mediated reactions, the allergens are gastroresistant and heat-stable proteins of low molecular weight (parvalbumin). On the other hand, isolated contact urticaria following the handling of raw fish but without symptoms after its ingestion was found among cooks and professional fish handlers. In these cases, the fish allergens are gastrosensitive and thermolabile, as demonstrated by the decrease in the diameter of the wheal in the skin-prick test using cooked fish. To the best of our knowledge isolated fish contact urticaria in children has not been previously reported. We analyze the features of three pediatric cases of contact urticaria from cod (one of them was sensitized to parvalbumin), with tolerance after ingestion of this fish on oral food challenge.
Mauro Calvani, MD, Iride Dello Iacono, MD, Valentina Giorgio, MD, Stefano Miceli Sopo, Valentina Panetta, MD and Salvatore Tripodi, MD.
Background: The diagnostic gold standard for food allergy is an oral food challenge (OFC) with the suspected food. Usually, an OFC is stopped at the onset of mild objective symptoms for fear of severe reactions. However, there is no consensus on this issue.
Objective: To investigate the effectiveness and side effects of a new model of oral milk challenge in order to increase the diagnostic accuracy of cow¡¯s milk protein allergy and reduce the number of many useless elimination diets. This model is characterized by a conservative diagnostic protocol and ¡°step-up cow’s milk administered dosing.¡± The secondary aim was to investigate possible factors influencing severe reactions.
Methods: Sixty-six children (median age 1 year, range 1¨C18) with suspected immunoglobulin E (IgE)-mediated cow’s milk allergy performed a conservative oral food challenge (OFC), i.e., the OFC was continued even in the presence of subjective, even repeated, or mild local or multiple organ objective symptoms. If the first objective reaction occurred when the quantity of milk was > 10 ml, the investigator would decide whether to continue the OFC or prescribe a gradual increase in milk feeding at home.
Results: Symptoms developed during the OFC in 42.4% of the children. Local, generalized and severe generalized reactions developed in 11 (16.7%), 11 (16.7%) and 6 (9.1%) children, respectively. Only 14/28 (50%) who developed objective symptoms during the OFC were considered to be affected by cow’s milk allergy. In the remaining 14 both subjective and objective symptoms developed and the OFC was continued without the emergence of additional symptoms. Epinephrine was administered to 6 of the 28 children (21.4%) who developed objective symptoms. All but one had subjective symptoms following the early doses of milk, whereas all children who later tolerated milk had their first subjective or mild symptoms following doses ¡Ý 10 ml.
Conclusions: This new model of oral milk challenge criteria led to frequent severe allergic reactions hence its use in daily practice seems inadvisable. However, our study provides evidence that a severe allergic reaction does not invariably occur if the offending food continues to be administered after the onset of symptoms. If mild symptoms appear at doses higher than 10 ml, continued milk administration, on the same day or in subsequent days, seems to facilitate the development of tolerance and may reduce the number of useless elimination diets.