Snapshot A 5-year-old child sees the pediatrician for a rash that began on her trunk and spread to her face and extremities. It began with small crops of tiny, red papules which progressed to teardrop vesicles on an erythematous base. These vesicles were noted to have grown cloudy in appearance, burst open, and have formed scabs. The pediatrician observes that the lesions appear to be at different stages of healing. Introduction Childhood (or adult) infection caused by the Varicella zoster virus Transmission occurs via respiratory droplets or contact with weaping skin lesions Varicella has an incubation period of 10-20 days Highly contagious contagion begins 24 hours before the rash appears lasts until crusting begins virus lays dormant in dorsal root ganglia of infected areas Recurrent infection in adults presents as shingles painful and serious manifestation of varicella zoster infection emerges along dermatomal distribution corresponding to affected dorsal root ganglia Chickenpox is a reportable disease as determined by the CDC Epidemiology in the past, parents would organize "chicken pox parties" to encourage herd immunity vaccination programs have now started to eradicate the disease in children in the US Presentation Symptoms prodrome occurs 24 hours before the onset of the rash and includes malaise mild fever anorexia myalgias rash pruritic lesions appear in crops over a period of 3-4 days begin as pink macules with "dew drop on a rose petal" appearance starts on face or trunk and spreads to extremities persists for about 1 week lesions remain infectious/contagious from 24 hours prior to eruption until crusty Physical exam may note that lesions appear to be at different stages of healing key difference between chickenpox and small pox Evaluation Diagnosis is based primarily on clinical observation and patient history Viral culture slow, but can assist in identifying pathogen PCR faster way to identify pathogen Differential Small pox, other viral exanthems Treatment Medical management observation alone the disease is self-limited in most cases in children oral acyclovir indicated in healthy adults with primary varicella infection IV acyclovir may be indicated in cases of severe disease or immunocompromised patients varicella immune globulin indicated in pregnant women with primary infection Prognosis, Prevention, and Complications Prognosis very good to excellent in most cases in children adults can have severe course and require more aggressive treatment Prevention vaccine is now available for infants, children, and immunocompromised adults vaccine must be given with great caution in the immunosuppressed and the patient should have cellular immunity still intact to some degree vaccination with live vaccines is generally contraindicated in patients with moderate/severe immunosuppression Complications secondary bacterial infections of the skin can occur at site of lesions other major complications include meningoencephalitis and hepatitis in immunocompromised children Reyes syndrome occurs in 10% of cases pneumonia and myalgias are more common in adolescents and adults can be transmitted via birth canal from infected mothers to newborns