Histopathological aspects of neutrophilic dermatoses: Investigation of 38 cases and review of the literature

Introduction: Neutrophilic dermatosis (ND) is a heterogeneous group of diseases with various etiologies and clinical presentations. NDs may clinically present as papule, vesiculopustule, plaque, and nodule of the skin, but they all share the common feature of neutrophilic predominance in the skin. Histological examination of patients with suspected ND is a key step for making the proper diagnosis. Patients and Methods: The aim of this article was to investigate histopathological aspects of different NDs. We obtained our data from medical records of patients at Razi dermatology hospital, between 2012 and 2014. Thirty-eight biopsy records coded under the term of any ND, including Sweet's syndrome (SS), pyoderma gangrenosum (PG), skin lesions of Behcet's disease, neutrophilic drug eruption, amicrobial pustulosis of the folds, pustular vasculitis of the hands, and undetermined ND were recruited in our study. The specimens were evaluated regarding inflammatory reaction pattern, epidermal/adnexal changes, and dermal changes. Results: Most common NDs in our study were PG (42.1%) followed by SS (21.1%). The most common pattern of inflammatory reaction was superficial perivascular and interstitial dermal inflammation in 44.7% of the patients. Exocytosis of neutrophils into epidermis, hair follicle, and eccrine gland was seen in 71%, 18.5%, and 28.9% of the specimens, respectively. Ulceration was only seen in ten PG specimens. Dermal fibrosis and vascular proliferation were reported in all PG patients. Conclusion: The prevalence of some histopathological findings in different types of ND was significantly different. These features seem helpful in distinguishing between different NDs