A previously healthy 27-year-old man comes to the clinic due to fever and rash. The patient is a missionary who recently emigrated from South Africa with his wife and 3 young children. Four days ago, he developed a high fever and malaise followed by the appearance of multiple discrete macules on his face, trunk, and extremities. The lesions are pruritic and evolved into pustules then vesicles. The patient has continued to develop new vesicles as other lesions crust over and heal. The remainder of the examination is unremarkable. This patient's symptoms are most likely due to an infection with which of the following pathogens?
Primary varicella | |
Epidemiology |
|
Clinical features |
|
Management |
|
This patient has classic symptoms of primary varicella-zoster virus (VZV) infection, a vaccine-preventable illness that causes varicella, or chickenpox. Primary infection usually occurs in children but can develop at any age, with severe illness occurring more often in adolescents and adults.
Transmission of VZV occurs via aerosolized droplets or direct contact, and a prodrome of fever, headache, and malaise typically develops after a 2-week incubation period. Within a day, a pruritic, maculopapular rash develops and evolves into pustules then vesicles. A characteristic finding in varicella is the development of successive crops of lesions on the face, trunk, and extremities, as seen in this patient with lesions in different stages of development (eg, crusted lesions, new vesicles). Vesicles crust over and resolve within 1-2 weeks. Once the primary infection has resolved, patients are at risk for reactivated infection (ie, herpes zoster).
(Choice A) Hand-foot-and-mouth disease, caused by coxsackievirus, presents with oral ulcers and a nonpruritic rash of variable morphology (eg, macular, vesicular) on the hands and feet. This patient's pruritus and lack of oral involvement make this diagnosis less likely.
(Choice B) Herpes simplex virus (HSV) in adults typically causes severe pharyngitis (primary infection) or a localized cluster of perioral vesicles (reactivated infection). Although HSV can cause a disseminated vesicular rash, this typically occurs in immunocompromised patients (eg, HIV). In addition, the rash is painful with vesicles in the same stage of development.
(Choice C) Human herpesvirus 6, which causes roseola infantum, most commonly presents with fever followed by a diffuse, maculopapular rash in young children. Vesicles would not be seen, and infection in immunocompetent adults is rare.
(Choice D) Parvovirus causes erythema infectiosum. Prodromal symptoms (eg, fever, headache) are followed by the development of malar erythema (slapped-cheek rash) and a reticular truncal rash. This patient's vesiculopustular rash makes parvovirus unlikely.
(Choice F) Variola virus causes smallpox, which is characterized by a vesiculopustular rash with lesions at the same stage of development, unlike in this patient. Moreover, smallpox has been eradicated due to vaccination.
Educational objective:
Primary varicella zoster virus infection presents with a prodromal illness (eg, fever, malaise) followed by pruritic, vesicular lesions that appear in successive crops in different stages.