Varicella zoster virus is a highly infectious virus that causes a vesicular rash and associated malaise, fever, and headaches. While the majority of the population has either had previous infection in childhood or vaccination, seronegative individuals are at risk of primary infection. Primary infection in pregnancy poses a risk of fetal transmission and congenital varicella syndrome, as well as risk of severe morbidity to the mother. Congenital varicella syndrome includes a conglomeration of anomalies such as cutaneous scarring, limb hypoplasia, microcephaly, and chorioretinitis. Seronegative mothers exposed to varicella should be treated with varicella immune globulin to reduce the risk of a primary varicella infection. If a pregnant woman develops varicella, oral acyclovir should be started to reduce the severity of infectious complications and the number of lesions. All women of reproductive age should be asked about their varicella status prior to conceiving. Varicella-naïve women should ideally complete the two-dose VARIVAX vaccine at least 4 weeks prior to conceiving.

A 38-year-old woman was referred to a dermatologist because of a rash in the face. She had been feeling low in energy for several months and in the past two months her arms and legs felt weak accompanied by myalgia. The rash had expanded to the extensor surfaces of hands and knees, upper chest, and neck. Serum CK was 4313 U/L (20 × ULN), and she was referred to the outpatient department for neuromuscular disorders with a presumed diagnosis of dermatomyositis.