Allergy to peanut oil--clinically relevant?

Abstract

The increasing prevalence of food allergies (especially allergy to peanuts) has led to a discussion of how safe topical preparations containing peanut oil are with respect to allergy. The major allergens from peanuts are proteins that have been characterized at a molecular level and cloned. Clinical signs of peanut allergy symptoms can be observed on the skin (urticaria), or in the gastrointestinal and/or respiratory tract culminating in cardiovascular symptoms and anaphylactic reactions. In most cases, symptoms are elicited by oral uptake; rarely, a contact urticaria has been described. In vegetable oils, the contents of protein differ depending on the production process: crude oils contain approximately 100 times more proteins than refined oils. This has clear-cut implications for allergic individuals. Quantitative data are available regarding elicitation of symptoms in allergic individuals with a threshold dose of 0.1-1 mg peanut allergen in oral provocation tests. There are anecdotal reports of adverse reactions after topical use of peanut oils. In one epidemiological trial, an association between topical use of skin care products containing peanut oil and the development of peanut allergy was observed; however, the data reflect a retrospective analysis without specifying skin care products containing peanut oil and also without analysing the quantity of topicals used. In contrast, oral tolerance was prevented and allergic sensitization was enhanced in a mouse model using high concentrations of peanut protein. So far, no reliable data are available regarding doses required to induce sensitization against peanut allergen via the epidermal route. A possible induction of sensitization against peanut proteins through contact with the skin via skin care products and the respective protein concentrations is a matter of speculation. Patients with atopic diseases, namely eczema, need appropriate skin care because of the disturbed skin barrier function. The benefit of avoiding damage to skin barrier functions of atopic individuals by the use of peanut protein-containing skin care products seems to outweigh possible risks of sensitization and/or allergy induction against substances contained in those products containing refined peanut oil.