The Case:
An otherwise healthy 3-year-old presented to the emergency department with a chief complaint of a pruritic rash for 2 days that started on the back and progressed down the arm to the hand. The child and his family were migrants recently arriving in the United States from South America and currently staying at a migrant shelter. The patient’s blood pressure was 104/60 mmHg, heart rate 100 BPM, respiratory rate 22 BPM, oxygen saturation 97% on room air, and temperature 37ºC (98.6ºF). On examination, the child was overall well-appearing, and significant only for a crusted-over patch of lesions was noted at the C6-7 dermatome on the child’s back lateral to midline, clustered papulovesicular lesions along the outer side of the left arm and involving the left hand along the C6-7 dermatome. The child was seen 9 days prior to presentation at the hospital-associated clinic for a general medical evaluation, and no rash was noted on exam. The child’s immunizations were up to date, including the first dose of the varicella vaccine. However, the recommended second dose was due at his 4-year check-up, which was scheduled for the following month.
Laboratory evaluation was significant for a complete blood count with a normal white blood cell count of 5400 cells/uL with a lymphocytic predominance of 46%. A basic metabolic panel and serum lactate results were normal. A sterile swab was used to rupture a vesicle on the forearm and sent for polymerase chain reaction analysis. Pediatric infectious disease was consulted for evaluation and follow-up. The sample tested positive for varicella-zoster virus and negative for herpes simplex virus. The child was diagnosed with varicella zoster (shingles) and treated with oral acyclovir 80mg/kg/day dosed every six hours for five days. The patient was discharged from the emergency department with next-day follow-up in clinic. Proper infection control measures were initiated, including isolation of the family and screening of close contacts at the patient’s shelter.
How common is herpes zoster in children?
Although rare, vaccine-type and wild-type varicella-zoster viruses are capable of producing herpes zoster infections in children [1-4]. The overall incidence rate in a study of six million children was found to be 78 per 100,000 person-years. Rates were highest amongst unvaccinated individuals, children aged 10-17, and immunocompromised individuals [1-4]. However, the incidence of herpes zoster in the pediatric population after the introduction of routine vaccination in the United States has steadily declined [1-4].
What is the diagnostic test of choice for pediatric herpes zoster infection? And, what is the management?
Viral polymerase chain reaction (PCR) testing is the diagnostic test of choice for both chickenpox and shingles to confirm the presence of the virus. A sterile swab is used to rupture a vesicle and is then placed in viral culture media for analysis. Once confirmed, the first-line treatment for non-complicated zoster is oral acyclovir 80mg/kg/day dosed every six hours for five days. However, if the zoster infection is complicated (e.g., signs of superimposed bacterial infection, cranial nerve involvement, or if the patient is immunocompromised), admission for treatment with intravenous acyclovir is warranted. Home isolation is recommended for all patients diagnosed with herpes zoster virus who are able to be discharged.
Authored by Michael Hohl, MD and Alisa McQueen, MD
References:
Iyer S, Mittal MK, Hodinka RL. Herpes zoster and meningitis resulting from reactivation of varicella vaccine virus in an immunocompetent child. Annals of Emergency Medicine. 2009;53(6):792-795. doi:10.1016/j.annemergmed.2008.10.023
Weinmann S, Naleway AL, Koppolu P, et al. Incidence of herpes zoster among children: 2003–2014. Pediatrics. 2019;144(1). doi:10.1542/peds.2018-2917
Harpaz R, Leung JW. The epidemiology of Herpes Zoster in the United States during the era of varicella and herpes zoster vaccines: Changing patterns among children. Clinical Infectious Diseases. 2018;69(2):345-347. doi:10.1093/cid/ciy954
Harpaz R, Ortega-Sanchez IR, Seward JF. Prevention of Herpes Zoster: Recommendations of the Advisory Committee on Immunization Practices (ACIP). Morbidity and Mortality Weekly Report. 1996;57(5):1-30. doi:10.1037/e547262006-001