To the Editor: I read the interesting study by Moravej et al1 on the predictive value of the cow's milk skin prick test in infantile colic. Infantile colic is a distressing issue both to parents and pediatricians as it is associated with various perinatal factors (maternal education, smoking habits, cheese consumption, hostility scores, and domestic violence) and having colic in infancy negatively affects the sleeping pattern and the height of the infant.2 The clinical implication of the Moravej et al's1 conclusion that exclusive breastfed infants with a positive skin prick test (SPT) might get benefits from the elimination of cow's milk from the maternal diet needs to be taken with caution due to the low number of positive SPT in the studied infants (2.6%) on the one hand and the need to institute a routine screening of all exclusively breastfed infants with colic by painful SPT on the other hand. Poor compliance of parents with SPT applied to their infants is also worrisome and needs to be considered. The atopy patch test has been recognized as a diagnostic tool for the verification of food allergies in infants and small children and is characterized by clinical signs associated with the digestive system. It was found to be positive in 32% of the children with gastrointestinal manifestations of food allergy. It targets specifically the delayed type hypersensitivity reactions, which are difficult to confirm with other diagnostic tools. It is furthermore simple to perform, noninvasive, and produces a minimum of undesired side effects. For these reasons, it should become part of the routine diagnostic toolset for food allergies to cow's milk in infants and children, and applied before a food challenge test.3 Therefore, it would be more prudent to recommend patch skin test rather than SPT as a diagnostic tool in discriminating exclusive breastfed infants with colic whom might require elimination of cow's milk from their mothers’ diet. This obviously necessitates extensive comparative studies.