To the Editor: In their report of a child with peanut allergy who developed sunflower seed allergy, Hsu and Katelaris caution against marketing claims of “safe alternatives” in allergic children.1 Their report also raises practical issues for those advising the parents of a child with food allergy: what is the risk of a new allergy developing; should a child with peanut or tree nut allergy avoid similar foods as well; and will food avoidance prevent new allergy from developing?