IL17A and pityriasis rubra pilaris: 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).