In this review, we highlight the potential implications of dysregulation of the IL-23/IL-17 axis in chronic inflammatory skin diseases, including psoriasis, hidradenitis suppurativa (HS), atopic dermatitis (AD), alopecia areata (AA), pityriasis rubra pilaris (PRP), pemphigus, and systemic sclerosis (SSc). Here, IL17A is linked to Alzheimer disease.