Pyoderma gangrenosum (PG), hidradenitis suppurativa (HS), and the spectrum of the associated autoinflammatory syndromes, including pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome, PSTPIP1‐associated myeloid‐related proteinemia inflammatory (PAMI) syndrome, pyoderma gangrenosum, acne, and hidradenitis suppurativa (PASH) syndrome, and pyogenic arthritis, pyoderma gangrenosum, acne, and suppurative hidradenitis (PAPASH) syndrome, are debilitating dermatological disorders characterized by chronic inflammation and tissue damage. The gene discussed is PSTPIP1; the disease is histiocytic sarcoma.