ABSTRACT
Herpes zoster (HZ) is associated with substantial morbidity. It is caused by reactivation of the latent varicella zoster virus (VZV) following decline in cell-mediated immunity, which is commonly age-related, but also occurs in individuals with immunosuppressive diseases and/or treatment. Since coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has been associated with T cell immune dysfunction and there have been reports of HZ in COVID-19 patients, we have performed a review of available literature on whether COVID-19 could trigger HZ. We identified 27 cases of HZ following COVID-19, which most frequently occurred within 1-2 weeks of COVID-19, and the majority of cases had typical presentation. Atypical presentations of HZ were noted especially in patients with lymphopenia. It has been hypothesized that VZV reactivation occurs as a consequence of T cell dysfunction (including lymphopenia and lymphocyte exhaustion) in COVID-19 patients. Based on current evidence, which is limited to case reports and case series, it is not possible to determine whether COVID-19 increases the risk of HZ. Practitioners should be aware of the possible increased risk of HZ during the pandemic period and consider timely therapeutic and preventive measures against it.
ABSTRACT
Ruxolitinib (RUX), a JAK1/JAK2 inhibitor, is approved for second-line therapy in patients with polycythemia vera (PV) who are resistant or intolerant to hydroxyurea. Due to the immunomodulatory and immunosuppressive effect of RUX, there is an increased susceptibility to infections. However, an increased risk of infection is inherent to even untreated myeloproliferative neoplasms (MPN). To obtain more information on the clinical significance of RUX-associated infections in PV, we reviewed the available literature. There is no evidence-based approach to managing infection risks. Most data on RUX-associated infections are available for MF. In all studies, the infection rates in the RUX and control groups were fairly similar, with the exception of infections with the varicella zoster virus (VZV). However, individual cases of bilateral toxoplasmosis retinitis, disseminated molluscum contagiosum, or a mycobacterium tuberculosis infection or a hepatitis B reactivation are reported. A careful assessment of the risk of infection for PV patients is required at the initial presentation and before the start of RUX. Screening for hepatitis B is recommended in all patients. The risk of RUX-associated infections is lower with PV than with MF, but compared to a normal population there is an increased risk of VZV infection. However, primary VZV prophylaxis for PV patients is not recommended, while secondary prophylaxis can be considered individually. As early treatment is most effective for VZV, patients should be properly informed and trained to seek medical advice immediately if cutaneous signs of VZV develop. Vaccination against influenza, herpes zoster, and pneumococci should be considered in all PV patients at risk of infection, especially if RUX treatment is planned. Current recommendations do not support adjusting or discontinuing JAK inhibition in MPN patients to reduce the risk of COVID-19.