Neutrophilic dermatoses.

Neutrophilic dermatoses are a group of rare heterogenous inflammatory disorders that share the presence of a sterile neutrophilic infiltrate on histopathology due to an underlying systemic illness, which can be a malignancy. This group of disorders can have diverse clinical presentations, including papules, plaques, nodules, vesiculopustular lesions, or ulcerations. We review the clinical and histopathologic features of several neutrophilic dermatoses that can be cutaneous manifestations of an underlying malignancy, including Sweet syndrome (acute febrile neutrophilic dermatosis), pyoderma gangrenosum, neutrophilic eccrine hidradenitis, subcorneal pustular dermatosis, erythema elevatum diutinum, Behçet's disease, Bazex syndrome, and VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) syndrome. We also discuss current treatment options. Cutaneous vasculitis, Schnitzler syndrome, and eosinophilic paraneoplastic dermatoses are also discussed in the context of cutaneous presentations of malignancy. These dermatologic conditions may precede underlying malignancy.