Question of the Day

Recommend a strict hypoallergenic diet trial to definitively diagnose cutaneous adverse food hypersensitivity/reaction (CAFR). Intradermal skin or serum allergen testing is not reliable for diagnosis of CAFR.

Clinical signs of food-induced and non-food-induced hypersensitivities (i.e., atopic dermatitis) are clinically indistinguishable so perform the hypoallergenic food trial before considering allergy testing otherwise it is difficult to interpret the results.

A positive response (i.e., improvement in signs) to an appropriate 8-week elimination diet using either a commercial hydrolyzed protein diet or a true novel diet with strict compliance plus a positive challenge trial (refeeding previous diet) at the end confirms the Dx of CAFR. If there’s no change with a proper elimination diet, proceed to allergy testing for non-food-induced atopic dermatitis.

The only Tx for CAFR is elimination of the food(s) causing the reaction. Also check for, and Tx, any secondary conditions such as skin infections (bacterial and/or fungal) or parasites (such as sarcoptic mange).

Also often need to use antipruritic measures (oral antihistamines, bathing). In very severely affected and uncomfortable patients, add a 1- to 2-week (max) course of corticosteroids.

Images courtesy of Dr. Patrick Hensel.