A case of herpes zoster in immune-competent and well-nourished 10-year-old girl

Abstract

Introduction

Herpes zoster in childhood is clinical entity which results from reactivation of latent varicella- zoster virus, typically following primary infection in early life. We report a case of HZ in an otherwise healthy child with no documented history of varicella infection or vaccination.

Case Presentation

A school-aged female presented with a 7-day history of painful, unilateral vesicular rash localized to the T9 dermatome. A suspected diagnosis was made clinically based on the characteristic dermatomal distribution and morphology of lesions. The lesions demonstrated a dermatomal distribution and did not cross the midline. Although laboratory methods such as Tzanck smear and polymerase chain reaction (PCR) can aid in confirmation, the classical presentation and limited resources made further molecular testing unnecessary. Differential diagnoses, including herpes simplex virus (HSV), were considered but deemed less likely due to the strict dermatomal pattern and absence of recurrent mucocutaneous lesions. The patient was treated with oral acyclovir initiated early in the course of illness, followed by rapid clinical improvement and an uncomplicated recovery.

Discussion

This case highlights that HZ can occur in immunocompetent children without a known history of varicella or vaccination, likely due to unrecognized primary infection or early-life exposure. It also emphasizes the importance of clinical diagnosis, the role of early antiviral therapy in improving outcomes, and the generally favorable prognosis of pediatric herpes zoster.

Conclusion

Herpes zoster should be considered in the differential diagnosis of children presenting with characteristic dermatomal vesicular eruptions, even in the absence of immunosuppression.

Highlights

• •Herpes zoster can occur in immunocompetent children even without a known history of varicella infection or vaccination.
• •Classical unilateral dermatomal vesicular eruption remains sufficient for clinical diagnosis in resource-limited settings.
• •Pediatric herpes zoster generally follows a mild clinical course with low risk of complications.
• •Early initiation of oral acyclovir therapy resulted in rapid symptom resolution and complete recovery.
• •Clinicians should consider herpes zoster in the differential diagnosis of dermatomal rash in children regardless of immune status.

Introduction

Herpes zoster is caused by the reactivation of latent varicella zoster virus (VZV), which remains dormant in sensory nerve ganglia following primary infection. The incidence of herpes zoster in children is not known and does not show seasonal variation in incidence. Importantly herpes zoster is not precipitated by exposure to individuals with varicella instead, such exposure may enhance cell mediated immunity in previously infected individuals, thereby reducing the risk of viral reactivation [1].

The lifetime risk of developing herpes zoster among individuals with a prior history of varicella is estimated to be 20–30%, with approximately 75% of cases occurring in individuals older than 45 years. Incidence rate increases significantly with age, especially after 50 years, and are higher in females than male [2], [3], [4]. In otherwise healthy children, particularly those younger than 10 years of age, herpes zoster had not been commonly described. However, children who acquire VZV infection in utero or during the first year of life have an increased risk of developing herpes zoster during early childhood.

In pediatric populations, herpes zoster generally follows a milder clinical course compared to adults. It is less frequently associated with sever acute pain, and postherpetic neuralgia is uncommon in immunocompromised children [5], [6]. In contrast, the disease occurs more frequently and may present more severely in children with compromised immune system, such as those receiving immunosuppressive therapy or living with HIV infection. Although the attenuated virus used in varicella vaccination can establish latency and subsequently reactivate, current evidence suggests that the risk of herps zoster is lower following vaccination that after natural infection in both healthy and immunocompromised children [7], [8], [9].

Presentation of case

History and physical examination

A 10-year-old girl presented with a seven days history of localized pain over the left flank, which was initially mild but progressively worsened. The pain was associated with myalgia and low-grade fever. Within a few days of symptom onset, she developed vesicular skin eruptions over the same region.

The rash was confined to the left flank and extended from the posterior midline toward the anterior abdominal wall, reaching the groin area (see Fig. 1). The lesions followed a dermatomal distribution and did not cross the midline. There was no history suggestive of immunosuppression, including chronic illness, recent infections, or use of immunosuppressive medications. By her age of 2 and 6 year, she was told to have pneumonia for which she took treatment admitted in nearby hospital. Otherwise, she had no other history of medical illness. She is vaccinated for her age according to the country’s vaccination guideline. Growth and development history is unremarkable; millstones were achieved at the expected ages.

Fig. 1.

A cluster of clear fluid filled vesicles on an erythematous base distributed along the dermatomal line.

On physical examination, the patient appeared well and in no acute disease. Her vital signs were within normal limits, with a recorded temperature of 37°C. Her weight is 32 kg and her height is 139 cm making her growth parameters and anthropometric measurements appropriate for her age. Systemic examination was unremarkable.

Dermatological examination revealed multiple grouped vesicular lesions on an erythematous base distributed along a unilateral dermatomal pattern over the left flank. The lesions were consistent with the typical clinical presentation of herpes zoster.

Diagnostic workup

Laboratory investigations showed a normal complete blood count. The erythrocyte sedimentation rate was 10 mm/hour, within the normal range. Liver and renal function tests were also within normal limits. Screening for HIV infection using a rapid diagnostic test was negative.

Based on the characteristic clinical features and supportive laboratory findings, a diagnosis of herpes zoster was made.

Treatment and follow-up

The patient was managed with oral acyclovir 600 mg po qid for 7 days. On her third day of treatment with acyclovir she started to have clinical improvement with resolution of pain and gradual healing of the skin lesions. No complications were observed during the course of treatment. Two weeks after the initiation of the drug, on her appointment, all the clinical symptoms and signs has improved except for healing scars and hypo pigmentations on the dermatomal distribution.

Discussion

Reactivation of VZV during infancy and early childhood is rare. However, it may occur in children who acquired the infection in utero or, less commonly, during early infancy. Even among children who experience primary varicella infection within the first year of life, reactivation is uncommon, particularly in immunocompetent individuals [10].Children who acquire VZV in utero or during early infancy are at somewhat higher risk for reactivation, though most cases still do not develop clinical herpes zoster [11], [12]. Although neither the patient nor her mother reported a known history of varicella infection and reactivation in early childhood, it can occur silently or with atypical presentations, particularly in children with lower immunity or specific risk factors [10], [12].Reactivation later in childhood can therefore occur even in the absence of a recognized history of chickenpox [13], [14].

The clinical presentation of HZ in children differs from that in adult. In pediatric patients, the disease is generally milder and less frequently associated with severe pain or postherpetic neuralgia. In very young children, assessment of pain may be challenging, however, in the present case, the patient was older and presented with localized pain preceding the onset of the rash, which is consistent with the typical prodromal phase of HZ [15], [16].

The earliest reported case of herpes zoster was described in a four-day old neonate in the United States. In that report, the infant had prenatal exposure to VZV, although no clinical varicella infection was observed during the neonatal period [17]. Cases from Nepal and other regions have documented HZ in infants as young as five months, often linked to intrauterine or early postnatal VZV exposure [18], [19], [20].

Most pediatric cases of HZ are thought to result from prior exposure to VZV, either through intrauterine transmission, perinatal exposure, or contact with infected household members. In a study approximately 56% of affected children had a documented history of VZV exposure [21], [22]. Nevertheless, cases without any identifiable history of prior infection in either the child or the mother have been reported. Childhood HZ has been reported to occur slightly more frequently in male and can involve any dermatome.

In adolescents, herpes zoster generally presents in a manner similar to adult, however, it is uncommonly reported in immunocompetent and well-nourished individuals. The present case highlights that HZ can occur even in otherwise healthy children without identifiable risk factors [8], [23]. A summary of previously published cases of herpes zoster in immunocompetent child is presented in the table below (Table 1).

Table 1.

A summary of a previously reported cases of herpes zoster in immunocompetent children and the present case.

Study/Reference	Age	Immunostatus	History of varicella/VZV exposure	Presentation	Outcome
Feldman, 1952 [17]	4 days	Immunocompetent	Prenatal VZV exposure	Neonatal HZ	Recovered
Kurlan et al., 2004 [24]	Infant	Immunocompetent	Postnatal VZV exposure	Localized dermatomal HZ	Favorable outcome
Hamed et al., 2024 [14]	toddler	Immunocompetent	No recognized prior varicella	HZ as initial manifestation of VZV infection	Recovered
Shameem et al., 2025 [19]	Infant	Immunocompetent	Presumed early-life exposure	Typical dermatomal HZ	Recovered
Present case, 2026	10-year	Immunocompetent	No known history of varicella infection or vaccination	Painful unilateral vesicular eruption involving T9 dermatome;	Complete recovery without complication

Diagnosis of herpes zoster is primarily clinical, based on the characteristic appearance of grouped vesicular lesions in a dermatomal distribution. Although a Tzanck smear can demonstrate multinucleated giant cells consistent with a herpesvirus infection, it cannot reliably differentiate between VZV and herpes simplex virus (HSV).

Even though polymerase chain reaction (PCR) testing is considered the gold standard for confirming varicella-zoster virus infection, it is typically reserved for atypical, disseminated, or diagnostically uncertain cases. According to the centers for disease control and prevention (CDC), PCR testing is mainly reserved for atypical presentations [25], [26].

As a differential diagnosis, a zosteriform herpes simplex should be considered where there is no painful prodrome, small vesicles of uniform in size with a smaller number of grouped vesicles, and high chance of recurrence. Some other differential diagnoses include drug eruption, zosteriform lichen planus, insect bite, folliculitis, dermatitis herpetiformis, and atopic dermatitis.

Overall, although routine antiviral treatment in healthy children is debated, early oral acyclovir administration appears safe and effective [27].

There is no clear consensus regarding antiviral therapy for herpes zoster in otherwise healthy children. Early antiviral therapy is thought to reduce viral replication, hasten cutaneous healing, and potentially shorten the duration of acute neuropathic pain. This case therefore supports the consideration of early antiviral therapy in selected pediatric patients with clinically significant or symptomatic herpes zoster. Apart from routine antiviral treatment, in healthy immunocompetent children with herpes zoster, a conservative treatment is the preferred approach including hydration, pain management and management for bacterial super infection. General preventive measures include maintaining good personal hygiene, especially regular hand washing, wearing appropriate clothing, and keeping exposed lesions covered with dressings. Fingernails should be kept short to minimize skin damage caused by scratching. In case where secondary bacterial infection develops, treatment with topical or systemic antibiotics may be necessary [28].

The patient had not received varicella vaccination. In this case, the absence of vaccination suggests that primary infection was most likely due to wild-type VZV acquired through natural exposure, potentially in a subclinical form. Nevertheless, HZ has been reported even in fully immunized children, indicating that vaccination reduces but does not eliminate the risk of viral reactivation.

Conclusion

Primary infection with VZV results in varicella (chickenpox), while subsequent reactivation of the latent virus leads to herpes zoster (HZ), which typically presents as a localized dermatomal vesicular lesion. Although it was previously known that herpes zoster virus most commonly occurs in late adulthood and elderly with underlying risk factor for immune-compromisation, it is also possible to have HZ in immune-competent children without any risk factor. Early recognition and prompt initiation of appropriate management are essential to ensure favorable outcomes and prevent potential complications.

Abbreviations

HZ: Herpes Zoster

HIV: Human Immunodeficiency virus

ICU: Intensive Care Unit

IDU: Intravenous Drug Use

VZ: Varicella-zoster

VAV: Varicella-zoster Virus

Ethics approval

The study was notified to the university ethics committee; but this is case report and it does not need a specific ethical approval.

Consent for publication

Written informed consent was obtained from the patient’s mother for publication of this case report. A copy of the written consent is available for review by the editor-in-chief of this journal on request.

Funding

This study did not receive any grants or funding from either for-profit or non-profit organization.

CRediT authorship contribution statement

Birhanu Kassie Reta: Writing – review & editing, Supervision. Ataklti Gebremedhin Weldemichael: Investigation, Data curation. Girmay Teklay: Writing – review & editing, Investigation, Data curation. Areaya Aregawi: Writing – review & editing, Writing – original draft, Visualization, Project administration, Data curation, Conceptualization.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Availability of data and materials

Data sharing is not applicable to this article as no data sets were generated or analyzed during the current study.