FLG and ichthyosis vulgaris: This is consistent with the published literature reporting similar changes in the morphology of the corneocyte surface in diseases associated with skin dryness, such as diabetes,32 psoriasis, and ichthyosis vulgaris.33 Reductions in NMF levels resulting from exposure to skin irritants or genetic factors such as filaggrin gene loss‐of‐function mutations in ichthyosis would lead to decreased hydration and shrinkage of the corneocytes, which might, in turn, cause the observed changes in the cell surface texture.