Biological features of KD may indicate a hypersensitivity reaction to an unknown allergen, more precisely, a type 1 reaction because of infiltrating mast cells and IgE reticulation in lesions.[13] Interestingly, atopy-related diseases, such as allergic rhinitis, allergic asthma, and atopic dermatitis were found in one-third of KD patients, suggesting a similar pathological process. This evidence concerns the gene IGHE and allergic asthma.