On the issue of the syndromic forms of pyoderma gangrenosum

Gangrenous pyoderma is an autoinflammatory polygenic neutrophilic dermatosis characterized by the formation of painful ulcerative skin defects with boldly raised undercut edges of purplish-cyanotic coloration and an erythema zone around the focus. Gangrenous pyoderma can manifest as an isolated dermatosis, and be associated with various autoinflammatory syndromes: PASH (gangrenous pyoderma, conglobate acne and purulent hydradenitis), PAPA (gangrenous pyoderma, pyogenic arthritis and conglobate acne), PAPASH (gangrenous pyoderma, pyogenic arthritis, conglobate acne and purulent hydradenitis), PAPASC (gangrenous pyoderma, pyogenic arthritis, conglobate acne, purulent hydradenitis and ulcerative colitis), etc. A number of genetic mutations have been found in the syndromic forms of gangrenous pyoderma (MEFV, NOD2, LPIN2, NLRP3, NLRP12, PSMB8, MVK, IL1RN, PSTPIP1) affecting inflammatory regulatory proteins, which contributes to the development of an autoaggressive process. Neutrophilic autoinflammatory syndromes have a common pathogenesis mechanism, which is an excessive activation of the innate link of the immune system, with hyperproduction of proinflammatory IL-1, IL-17 and chemokines, leading to aseptic neutrophilic inflammation of the skin. At the moment, the treatment of syndromic conditions remains a difficult task. Systemic glucocorticosteroids, immunosuppressants, antimetabolites, and sulfone preparations are used in complex therapy, however, more and more studies indicate the possibility of therapy with genetically engineered biological drugs with TNF inhibitors, IL-1 and IL-17. We present two clinical observations of rare forms of autoinflammatory neutrophilic syndromic conditions PASH and PAPASC in patients aged 20 and 21 years.