Purpose of Review Neutrophilic dermatoses are defined by the presence of a sterile neutrophilic infiltrate on histopathology. This review focuses on the pathogenesis, epidemiology, clinicopathological features, diagnosis, and management of four disorders: Sweet syndrome, pyoderma gangrenosum, Behçet syndrome, and neutrophilic eccrine hidradenitis.Recent Findings Recent studies have provided insight into the complex pathogenesis of neutrophilic dermatoses. Evidence supports an intricate interplay of abnormal neutrophil function and inflammasome activation, malignant transformation into dermal infiltrating neutrophils, and genetic predisposition. Summary Neutrophilic dermatoses have diverse cutaneous and extracutaneous manifestations and may be associated with significant morbidity and mortality. Common underlying associations include infectious, inflammatory, and neoplastic disorders, as well as drug reactions. Emerging diagnostic and therapeutic frameworks identify an expanding role for biologic and targeted anti-inflammatory therapies. KeywordsAcute febrile neutrophilic dermatosis • Behçet disease • Neutrophilic dermatosis • Neutrophilic eccrine hidradenitis • Pyoderma gangrenosum • Sweet syndrome This article is part of the Topical Collection on Hospital-Based Dermatology

Argyria is a rare but cosmetically distressing and difficult-to-treat condition for which quality-switched (Q-switched) lasers have been most commonly employed. However, at least one previous report suggests that the picosecond alexandrite laser may also serve as a successful treatment modality. Herein, we present a side-by-side comparison of a picosecond 755-nm alexandrite laser and a Q-switched 1064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser in the treatment of argyria. Our results reveal an equivalent success of the picosecond alexandrite when compared to the more commonly employed Q-switched Nd:YAG, suggesting that the picosecond 755-nm alexandrite laser is equally effective in the treatment of argyria.