Controlled oral food challenges in children – when indicated, when superfluous?

Abstract

The diagnostic work‐up of suspected food allergy includes the skin prick test (SPT), the measurement of food specific immunoglobulin E (IgE) antibodies using serologic assays, and more recently the atopy patch test (APT). For specific serum IgE and the SPT, decision points have been established for some foods allowing prediction of clinical relevance in selected cases. The APT may be helpful, especially when considered in combination with defined levels of specific IgE. Controlled oral food challenges still remain the gold standard in the diagnostic work‐up of children with suspected food allergy. Most food allergic children will lose their allergy over time. As there is no laboratory parameter, which can accurately predict when clinical tolerance has been developed, controlled oral food challenges are the measure of choice. In this article, the current knowledge of predictors for the outcome of oral food challenges is reviewed and proposals for the daily practical work‐up in the case of suspected food related clinical symptoms are presented.

Potential, pitfalls, and prospects of food allergy diagnostics with recombinant allergens or synthetic sequential epitopes

“…[58], [99] and [100] In general, these studies verified that increasing sIgE titers correlate with an increasing risk of reactivity on challenge and that reasonable threshold values can be defined to avoid challenges in a subgroup of patients. [58], [71], [89], [101], [102], [103], [104] and [105] However, diagnosis of food allergy based on decision points is hampered by a huge overlap in test reactivity between healthy subjects and patients with food allergy.…”

Allergic Rhinitis and its Impact on Asthma (ARIA) 2008*

“…The presence of food-specific IgE in serum or a positive skin test to a foodstuff does not always correlate with food allergic symptoms because many patients outgrow their allergy with age (1383,1384) and not all patients with food-specific IgE have a clinical sensitivity (1385). In many instances, the diagnosis has to be confirmed by a double-blind food challenge that should be carried out under precisely specified conditions (1386)(1387)(1388) and by trained staff who have the competence to manage anaphylactic reactions. As for other forms of allergy, unproven and controversial techniques such as food-specific IgG or cytotoxic tests have no proven value (1).…”

Manifestaciones Alérgicas en el Primer Año de Vida

“…También resulta interesante que en todos los casos el diagnóstico no se haya podido confi rmar mediante un desafío en doble ciego 28,29 debido a la reticencia de los padres a aceptarla; este mismo fenómeno ocurrió en un estudio que reportamos anteriormente 30 . Esto explica porqué el diagnóstico se basó en la respuesta a la dieta de eliminación, posibilidad que ha sido planteada por algunos autores cuando no se puede aplicar una prueba de desafío en doble ciego 3,29,31,32 . Como es frecuente al usar la metodología aplicada en este estudio, que aborda un núme-ro elevado de casos en el seguimiento, no se pudo evaluar el papel que juegue los exáme-nes de laboratorio como apoyo al diagnóstico clínico 3,32 .…”

“…Esto explica porqué el diagnóstico se basó en la respuesta a la dieta de eliminación, posibilidad que ha sido planteada por algunos autores cuando no se puede aplicar una prueba de desafío en doble ciego 3,29,31,32 . Como es frecuente al usar la metodología aplicada en este estudio, que aborda un núme-ro elevado de casos en el seguimiento, no se pudo evaluar el papel que juegue los exáme-nes de laboratorio como apoyo al diagnóstico clínico 3,32 . Esto impuso una limitación en la capacidad de análisis, sin embargo, en seguimientos de este tipo, en que no se cuenta con los detalles médicos clínicos, esto es frecuente y explica el uso de una clara respuesta clínica a la dieta de eliminación para defi nir al caso como alérgico [28][29][30][31][32] .…”