An otherwise healthy 22-month-old was referred for evaluation of a pruritic rash on her buttocks and right leg of 5 days' duration. Her mother reported that the rash had begun as red bumps and blisters on the buttocks that subsequently spread to the right leg. The child had no history of fever and was up-to-date on all immunizations, including varicella vaccine (which she received at 12 months). She stays home during the day, while her 4-year-old sister, who received the varicella vaccine 3 years earlier, attends nursery school. Neither child had been exposed to chickenpox. There was no history of maternal varicella during pregnancy.
Groups of erythematous vesiculopapules were noted on the right side of the buttocks extending to the right anterior shin in an L4 dermatomal distribution (A and B). There was no adenopathy.
Julie L. Cantatore-Francis, MD, and Yelva Lynfield, MD, of Brooklyn, NY, diagnosed herpes zoster, most likely caused by the reactivation of the varicella-zoster virus. This highly contagious double-stranded DNA virus is a member of the herpesvirus group. Chickenpox is the primary infection; herpes zoster (shingles) represents recurrent infection. Since the varicella vaccine is a live attenuated virus (Oka strain) vaccine, herpes zoster may occur in vaccine recipients. Studies have demonstrated that the incidence of herpes zoster is lower in vaccinated children than in naturally infected children. However, it is important to recognize that wild-type viruses can also cause herpes zoster in children given an Oka strain vaccination.
Herpes zoster presents as a unilateral eruption of grouped vesicles on an erythematous base. Thoracic dermatomes are involved in most cases, followed in frequency by cervical, trigeminal, lumbar, and facial nerve regions.
Complications include post-herpetic neuralgia, secondary bacterial infection, scarring, herpes zoster ophthalmicus, Ramsay Hunt syndrome, meningoencephalitis, motor paralysis, and hepatitis. The severity and incidence of complications increase with age and immunodeficiency. Herpes zoster usually resolves without sequelae in healthy children and young adults. Vaccine-induced herpes zoster in healthy children has been mild and has not been associated with the common complication of pain, as was the case in this patient.
Early treatment with antiviral agents (acyclovir, famciclovir(, or valacyclovir) within 72 hours of onset of the first vesicle can decrease the duration of the illness and associated pain. Oka strain herpes zoster can cause Oka strain varicella in nonimmune patients.
This patient was treated with oral acyclovir, 80 mg/kg/d, divided into 4 doses. After 7 days, many of the vesicles had crusted and had begun to heal.