Assessing the Risk of Omalizumab Add-on Therapy for Chronic Idiopathic Urticaria during the COVID-19 Pandemic

Amid the current COVID-19 pandemic, there is concern for increased risk of infection while on immunomodulatory therapy. Omalizumab, a monoclonal antibody, is an add-on therapy for the treatment of chronic idiopathic urticaria (CIU) when first line therapy alone fails to achieve appropriate response. Current understanding of the response to COVID-19 infection is largely varied and actively under investigation. In the context of a pandemic, it is important to consider the safety profile of omalizumab as it modulates the immune system. We reviewed data from pivotal Phase III clinical trials investigating omalizumab use in CIU patients with a focus on reported respiratory-related adverse events (AEs) to assess these risks. Results from three phase III trials show that omalizumab adjunct therapy does not significantly increase infection risk and severity.

Estimating the susceptibility to SARS-CoV-2 infection with rituximab use for pemphigus vulgaris

The occurrence of the COVID-19 pandemic has raised new uncertainties for dermatologists and their patients, importantly concerning initiation and continuation of immunosuppressants for dermatological conditions at this time. We review two phase III trials of rituximab, a chimeric CD20 monoclonal antibody, used for the treatment of pemphigus vulgaris. Without specific data studying rituximab use and susceptibility of SARS-CoV-2, we hope to utilize available data in order to assist clinician decision making for rituximab in the context of the pandemic.

KRAS 117N positive Rosai-Dorfman disease with atypical features

Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy, is a rare disease typically characterized by a histiocytic proliferation within lymph nodes, which is due to an unknown etiology. Extranodal involvement can occur, and it more rarely can involve the skin. RDD generally presents with an indolent nature and follows a benign disease course, although more aggressive cases have been reported. The condition predominately affects children and young adults. It is classically characterized by massive, bilateral painless lymphadenopathy and accumulation of CD68-positive, S100-positive, CD1a-negative histiocytes, with the presence of emperipolesis as a hallmark. Herein, we present an aggressive case in a 76-year-old male with past medical history significant for prostate cancer, who presented with a 7-month history of lymphadenopathy and new onset of multiple large abdominal wall, cutaneous, lymph node, liver, and lung masses, all of which were histopathologically atypical, but showed features consistent with RDD, including emperipolesis and strong S100 positivity. Molecular studies showed a KRAS 117N mutation, which has been recently reported in RDD. While most cases present as a benign tumor, this case demonstrated aggressive features clinically, showed partial response to MEK inhibitor immunotherapy in the setting of a KRAS mutation, and demonstrated atypical cytologic features on histopathology.