Syndromic HS forms, including Pyoderma gangrenosum, Acne, and Suppurative Hidradenitis (PASH) and Pyogenic Arthritis, Pyoderma gangrenosum, Acne, and Suppurative Hidradenitis (PAPASH) syndromes, involve genetic changes in PSTPIP1, NLRP3, and other autoinflammatory genes (112, 113). The gene discussed is NLRP3; the disease is histiocytic sarcoma.