September 2006

A 4-year-old boy presented with a history of several blisters on his left leg for two days. They were somewhat itchy. He had a low grade fever. He had a negative travel history and lived with his parents, and older sibling and maternal grandmother. What is your diagnosis?

Answer

The diagnosis is shingles (a.k.a. varicella zoster or herpes zoster).

This diagnosis is most common in adults older than 50, however, it can be seen in children. The children who have had varicella before the aged 1 are particularly at risk. The incidence is approximately 74 per 100,000 patient years. One retrospective study showed the incidence to be 40 times higher in children with systemic lupus erythematosus (SLE), compared with immunocompetent children and higher in children with SLE than children with stem-cell or solid organ transplants. Shingles is less common in vaccinated healthy people as compared with individuals who have had natural varicella.

The virus remains dormant in the dorsal root ganglia and becomes reactivated. Upon reactivation, patients develop grouped papulovesicular lesions distributed in 1-3 contiguous dermatomes. Children generally have less pain than adults, and postherpetic neuralgia is very rare in children. Immunocompetent children may have a low grade fever and malaise. Immunocompromised children will have a more prolonged course with more dermatomes involved and may possibly develop viremia.

The diagnosis is typically made based on the clinical findings. Other methods for diagnosis include: a demonstration of multinucleated giant cells in a Tzanck smear from a lesion (seen from all viruses in the herpesvirus group); direct immunofluorescence antibody test; or a positive culture for varicella zoster from a vesicle (better results are noted from newer lesions although cultures for varicella are more difficult than for herpes simplex virus (HSV).

Differential diagnoses for this condition include recurrent HSV lesions and allergic contact dermatitis.

Treatment of shingles in immunocompetent children is symptomatic. Oral antihistamines may be helpful as well as protective clothing to avoid excessive stimulation. Involvement of the ophthalmic branch of the trigeminal nerve warrants consultation with an ophthalmologist and potentially more aggressive therapy. If the vesicles continue to develop after 72 hours or the child is immunocompromised, acyclovir can be prescribed in addition to zoster immune globulin as indicated. A new vaccine has been recently approved for reducing the risk of shingles in older adults.

For more information:

• Visit www.cdc.gov/ncidod/diseases/list_varicl.htm
• Lee PP, et al. Herpes zoster in juvenile-onset systemic lupus erythematosus. Incidence, clinical characteristics and risk factors. Pediatr Infect Dis J. 2006;25:728-732.
• Goldman GS. Universal Varicella Vaccination: efficacy trends and effect on herpes zoster. Int J Toxicol. 2005;24:205-213.
• Binder NR, et al. Herpes zoster ophthalmicus in an otherwise-healthy Child. J AAPOS. 2004;9:597-598.
• Mitka M. FDA Approves shingles vaccine. JAMA. 2006;296:157-158.