Neutrophilic dermatoses: Sweet syndrome and gangrenous pyoderma. Literature review and own clinical observations

Neutrophilic dermatoses are a heterogeneous group of inflammatory skin diseases that have unique clinical features, but are combined by the presence of a sterile, predominantly neutrophilic infiltrate at histopathological examination. Neutrophilic dermatoses include Sweet syndrome, gangrenous pyoderma, Behcet’s disease, neutrophilic urticaria, subcorneal pustular dermatosis, palmoplantaris pustulosis, acrodermatitis Allopo, acute generalized exentematous pustulosis, infant pustulosis, etc. The morphology of skin lesions associated with these diseases is heterogeneous, which makes diagnosis challenging. In addition, a thorough clinical evaluation of patients is necessary to exclude diseases that mimic these disorders and to diagnose potential concomitant infectious, inflammatory, and tumor processes. While some neutrophilic dermatoses may disappear spontaneously, most require treatment to achieve remission. A delay in diagnosis and treatment can lead to significant morbidity and even mortality in these patients. Glucocorticoids are the drugs of choice for the treatment of neutrophilic dermatoses. In case of their ineffectiveness, other biological disease-modifying antirheumatic drugs may be administered depending on the severity of the skin lesion, chronicity of the disease, the presence of systemic lesions, and refractory status. This work is devoted to epidemiology, etiopathogenesis, clinical features, diagnostic signs and modern methods of treating Sweet syndrome and gangrenous pyoderma based on a review of modern literature and our own clinical observations.