Cutaneous adverse food reactions

The terms food allergy and food hypersensitivity should be reserved for those adverse reactions to food that have immunologic basis. Food intolerance refers to cutaneous adverse food reactions (CAFR) as a result of non-immunologic mechanisms, although distinguishing between the two can be very difficult, with diagnosis and treatment pathways being similar (Bethlehem et al, 2012; Mueller et al, 2016). Gaschen and Merchant (2011) suggested in a review of studies that only 1–6% of all dermatoses seen in practice relate to adverse food reactions and that food allergies constitute 10–20% of allergic responses in dogs and cats (Figure 1). A full dermatological work up is required before a nutritional factor can be entirely confirmed. It can be commonplace, however, for owners to self-diagnose their pet's food allergy or intolerance, even before seeing the veterinary surgeon (Tiffany et al, 2019). There are many diets available that are gluten free, grain free, hypoallergenic and/or natural (Table 1); and when the pet improves on these diets the owners assume that their pet had an allergy to one of the ingredients, in many cases it is purely a coincidence (Tiffany et al, 2019). These diets can appeal to many owners that are looking for a way to help their pet.