Atopy Patch Test (APT)--its role in diagnosis of food allergy in atopic dermatitis.

During the past few years, the Atopy Patch Test (APT) has become a valuable additional tool in the diagnostic work-up of food allergy in infants and children with atopic dermatitis. A positive APT may help to prevent restrictive and unnecessary diets which may be the consequence of misjudging late reactions by clinical assessment alone. Furthermore, the combination of positive atopy patch tests together with defined levels of specific IgE (cow milk = 0.35 kU/l and egg = 17.5 kU/l) makes DBPCFC superfluous for suspected milk and egg allergy. However, several open questions indicate the need for further studies.