Neutrophilic Dermatosis and Management Strategies for the Inpatient Dermatologist.

Purpose of Review: Neutrophilic dermatoses are a heterogeneous group of disorders with significant overlap in associated conditions, clinical presentation, and histopathologic features. This review provides a structural overview of neutrophilic dermatoses that may present in the inpatient setting along with diagnostic work-up and management strategies. Recent Findings: Sweet's syndrome has been found in patients with coronavirus disease 2019 (COVID-19). Pyoderma gangrenosum (PG) has been shown to be equally associated with ulcerative colitis and Crohn's disease. A clinical trial shows that cyclosporine is equally effective as prednisone in treating PG. Neutrophilic eccrine hidradenitis has been found in the setting of newer antineoplastic medications, such as BRAF inhibitors, as well as in the setting of malignancy without chemotherapy exposure. Summary: Neutrophilic dermatoses are a rare and complex group of dermatoses with varying and overlapping clinical presentations. Physicians should be aware of the growing list of associated diseases in order to build a better differential diagnosis or to potentially investigate for co-existing disease.

Association of Bullous Pemphigoid With Immune Checkpoint Inhibitor Therapy in Patients With Cancer: A Systematic Review.

Importance: There is limited information on immune checkpoint inhibitor-induced bullous pemphigoid (ICI-BP) in patients with cancer, with most existing studies being case reports or small case series from a single institution. Prior review attempts have not approached the literature in a systematic manner and have focused only on ICI-BP secondary to anti-programmed cell death 1 (PD-1) or programmed cell death ligand 1 (PD-L1) therapy. The current knowledge base of all aspects of ICI-BP is limited. Objective: To characterize the risk factors, clinical presentation, diagnostic findings, treatments, and outcomes of ICI-BP in patients with cancer as reported in the current literature. Evidence Review: A systematic review was performed using PubMed, Embase, Web of Science, and the Cochrane Database of Systematic Reviews according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. Articles reporting data on individual patients who met preestablished inclusion criteria were selected, and a predefined set of data was abstracted. When possible, study results were quantitatively combined. Findings: In total, 70 studies reporting data on 127 individual patients undergoing ICI therapy for cancer (median [IQR] age, 71 [64-77] years; 27 women [21.3%]) were included. In pooled analyses, patients ranged in age from 35 to 90 years. Immune checkpoint inhibitor-induced bullous pemphigoid often occurred during the course of anti-PD-1, PD-L1, or cytotoxic T lymphocyte-associated antigen 4 therapy but was also found to develop up to several months after treatment cessation. Prodromal symptoms, such as pruritus or nonspecific skin eruptions, were found in approximately half of the patient population. Histopathologic or serologic testing, when undertaken, was a helpful adjunct in establishing diagnosis. Treatment with immunotherapy was discontinued after ICI-BP development in most patients. The most common treatments were systemic and topical corticosteroids. Steroid-sparing therapies, such as antibiotics and other systemic immunomodulators, were also used as adjuvant treatment modalities. Biologic and targeted agents, used predominantly in cases refractory to treatment with corticosteroids, were associated with marked symptomatic improvement in most patients. Conclusions and Relevance: The results of this systematic review suggest that ICI-BP often poses a therapeutic challenge for patients with cancer who are receiving immunotherapy. Further research on the early recognition, diagnosis, and use of targeted treatment modalities will be essential in developing more personalized treatment options for affected patients while minimizing morbidity and mortality.