This patient should be placed on airborne and contact precautions. Varicella-zoster virus can be transmitted from persons with zoster to susceptible hosts (that is, those who have never had chickenpox and are not vaccinated against it) who may develop chickenpox as a result of the exposure. The virus can spread through direct contact with active lesions, which is most common with localized zoster. Localized zoster is defined as rash in one or two dermatomes, most commonly along a thoracic dermatome, that does not cross the midline. Patients with localized zoster who are not immunocompromised can be managed with contact precautions alone; a person is no longer infectious after all the lesions have crusted over. Disseminated zoster is defined as a more widespread rash involving three or more dermatomes. Disseminated zoster can appear similar to varicella (chickenpox). Vesicles usually appear in various stages of development and generally form over 3 to 5 days before they start to dry and crust over. Immunocompromised persons (such as this patient) are at increased risk for disseminated zoster, which may involve the respiratory tract. In patients with disseminated zoster or those who are immunocompromised, the virus may be transmitted via the airborne route from infected small (≤5 µm) respiratory droplet nuclei that can remain suspended for extended periods or travel long distances on air currents. Airborne (negative-pressure room) and contact precautions are appropriate management for patients who have disseminated zoster or localized zoster and are immunocompromised. Other organisms transmitted via the airborne route include those causing tuberculosis, measles, and chickenpox.

Droplet precautions are applied for organisms that are transmitted via large (>5 µm) droplets that travel less than 3 feet on air currents (such as respiratory, pertussis, and mumps viruses).