Cashew allergy: observations of 42 children without associated peanut allergy

Cashew allergy seems to be increasingly frequent. The goal of the present study was to analyse the clinical features and results of investigations of 42 children with cashew allergy.

The clinical features and results of skin prick tests, specific IgE assays, and food challenges were analysed.

The mean age at first allergic reaction was 2 years and the mean age at diagnosis of cashew allergy was 2.7 years. One in five children (12%) had a prior history of exposure to cashew nuts. Fifty-six per cent had skin symptoms, 25% had respiratory signs and 17% had digestive signs. Eighteen children had proven, associated food allergies (pistachio, seven; egg, five; mustard, three; shrimp, two; cow milk, one). The mean wheal diameter of the skin prick tests was 7 mm (3-16 mm) and the mean specific IgE level was 3.1 kUA/L (<0.35->100 kUA/L). Eight children had positive food challenges.

The increase in cashew allergy is worrying because it affects young children who may have a reaction without ever having been exposed to cashews. Almost one-third of children are allergic to pistachios, which belong to the same botanical family as cashews. Clinical history is generally and sufficiently suggestive to diagnose cashew allergy without recourse to food challenges.