Frequency of Oral Mucositis and Local Virus Reactivation in Herpes Simplex Virus Seropositive Children with Myelosuppressive Therapy.

BACKGROUND Oral mucositis (OM) is a common chemo- and radiotherapy adverse effect in oncological pediatric patients. Herpes simplex virus (HSV) infection can cause a severe clinical course. We hypothesize, that HSV seropositivity is a risk factor for local HSV-1 reactivation and increased frequency of OM in patients with myelosuppressive therapies. PATIENTS AND METHOD We evaluated the prevalence of seropositivity of HSV-1 between June 2011 and April 2014 in patients with potential oncological disease and correlated it to the frequency of OM and local viral reactivation in OM under myelosuppressive therapy. RESULTS The overall rate of HSV-seropositivity in our cohort was 22%. 48 patients underwent myelosuppressive therapy. Of these, 7 were HSV-1 IgG positive and 41 negative. All patients with OM under myelosuppressive therapy and positive local swab for viral HSV (l-PCR) were HSV-1 IgG positive before the start of therapy (100%). The absolute risk for OM in HSV-1 IgG positive patients was increased by 58.5% (95%CI: 20.0  - 72.2%) corresponding to a relative risk (RR) of 2.4 (95%CI: 1.7-3.5, P=0.009). The multivariable adjusted OR to suffer 2 or more OM episodes in HSV-1 IgG positivity was 8.8 (95%CI: 1.5-95.8, P=0.014). DISCUSSION AND CONCLUSION In HSV-1 IgG positive patients half of the OM episode showed HSV reactivation, and the risk for multiple OM episodes was increased. These patients should be investigated for HSV-infection in every OM episode. Prophylactic and preemptive therapeutic measures should be discussed early, but prospective data on HSV prophylaxis and preemptive treatment is required.