By Gary M. White, MD
Chickenpox, also known as varicella, is a vesicular dermatosis in children caused by infection by the varicella-zoster virus. The incubation period is 2-3 weeks. For chickenpox in the neonate, see neonatal varicella.
The patient develops tens to hundreds of vesicles that appear as dew drops on a rose petal. The patient commonly experiences malaise, fever, and a headache. The lesions may heal leaving depressed scars. Potential complications include bacterial superinfection (e.g., cellulitis or bullous impetigo) and pneumonia. Group A streptococcal disease may cause a serious infection.
Rarely, chickenpox may occur in a photodistributed distribution. In most of these cases, the eruption was preceded by an episode of either sunburn or intense sun exposure 2-10 days previously. Most lesions are at the same stage of development and the lesions may be rather dense, and individual lesions larger, than is typical [PD 2014:Sept Photoquiz].
Recurrent varicella is rare in immunocompetent individuals, but may occur [Cutis 2016;97;65].
Patients benefit from acyclovir if therapy is instituted within 72 hours of the onset of the rash. This is particularly true of adults (dosed at 800 mg 5/day) but less so of children.
Dosing for acyclovir may be more accurately calculated as 20 mg acyclovir/kg bodyweight (not to exceed 800 mg) four times daily.
In one study of children exposed to chickenpox, acyclovir 40-80 mg/kg/day given QID greatly decreased the skin manifestations and fever, but did not prevent seroconversion. Symptomatic therapy includes calamine lotion, cool baths and compresses, antipyretics (except aspirin so as not to precipitate Reye's syndrome), and rest. For the treatment of varicella in the immunocompromised patient, acyclovir IV (e.g., 500 mg/m2 Q 8 hours) until healing occurs is recommended. A vaccine is available and is approved in the US. It is usually given to children 12-18 months of age.
A young woman with chickenpox.