Yang H, Chen JS, Zou WJ, et al. - This study was undertaken to determine if vitamin A deficiency (VAD) can exacerbate atopic dermatitis (AD) development and explore the possible pathophysiologic mechanism. Serum vitamin A (VA) concentration was detected in different phenotypes of AD infants (intrinsic AD, iAD and extrinsic AD, eAD), and established ovalbumin (OVA) percutaneous sensitized AD model and passive cutaneous anaphylaxis (PCA) model on VAD and vitamin A supplementation (VAS) model in wild‐type mice (C57BL/6) and established AD model on both normal VA (VAN) and VAD feeding mast cell deficiency mice (ckitw‐sh/w‐sh). According to results, the average eAD serum VA concentration was significantly lower than that of iAD, as well as healthy controls. VAD may exacerbate extrinsic AD by increasing Th2‐mediated inflammation and mast cell activation. Therapeutic VAS may rescue VAD‐aggravated eAD. It could provide a new strategy to prevent or treat atopic dermatitis in the future.