Abstract

OBJECTIVES : Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune disease with highly heterogenous clinical manifestations and severity. Herpes zoster (HZ) is a viral disease caused by reactivation of varicella-zoster virus which remains dormant in the dorsal root sensory ganglia after a previous varicella infection. There is limited information on the association between HZ and childhood-onset SLE (cSLE). This study aimed to determine the risk factors for HZ in patients diagnosed with cSLE.

PATIENTS AND METHODS : Single-center retrospective cohort study which included all patients less than 19 years old with SLE at a tertiary hospital in the Philippines.

RESULTS : A total of 388 patients were included in the study. The prevalence of HZ was 15.72%, with an incidence rate of 38.40 per 100 person-years. The most common location of the HZ was the upper extremities (18.03%). The median SLEDAI at HZ diagnosis was 4, 16.39% had recurrent HZ, 11.48% had superimposed bacterial infection, and more than two-thirds were treated with acyclovir or valacyclovir (88.52%). The proportion of participants with renal manifestations was significantly higher among those with HZ (54.10% vs. 40.37%). Glucocorticoid dosage ≥5mg, azathioprine, and intravenous cyclophosphamide significantly predict the likelihood of developing HZ. In particular, IV cyclophosphamide, azathioprine, and glucocorticoid doses of ≥5mg increased the risk for the development of HZ by 1.61 (p=0.048), 2.07 (p=0.009), and 10.20 (p=0.001) times, respectively.

CONCLUSION : The prevalence and incidence of HZ in cSLE patients are 15.72% and 38.40 per 100 person-years, respectively. The risk factors identified for HZ among cSLE patients were lymphopenia, lupus nephritis, and immunosuppressive agents. Glucocorticoid dosage ≥5mg, azathioprine, and intravenous cyclophosphamide significantly predict the likelihood of developing HZ.