One of the classic signs of herpes zoster (HZ, or shingles) is a painful and blistering red rash that appears in a narrow band across 1 or 2 adjacent dermatomes, an area of skin that is mainly supplied by branches of a single spinal sensory nerve root. In cases of localized zoster, the rash typically does not cross the body’s midline.
However, sometimes the rash is more widespread, affecting 3 or more dermatomes. This is known as disseminated zoster, which can be difficult to distinguish from varicella (chickenpox). The condition is also known as disseminated cutaneous HZ (DCHZ). It is commonly defined as more than 20 skin lesions beyond the primary or adjacent dermatomes. DCHZ generally occurs only in individuals with compromised or suppressed immune systems.
Whether disseminated or localized, the early symptoms of shingles include headache, flu-like symptoms minus a fever, and sensitivity to light. A red and blistering rash develops a few days after the onset of these symptoms and may be accompanied by itching, tingling, or extreme pain in the area surrounding it.
The fluid in the blisters contains the varicella zoster virus, which had remained dormant in the host’s body since an earlier case of chickenpox years or decades before. If a person who has not had chickenpox or been vaccinated against it comes in contact with the fluid and then touches their mouth, nose, or eyes, they are likely to contract chickenpox. Once the virus is in their body, they are also at risk of developing shingles at a later date.
Although the spread of localized zoster can be managed by following the standard precaution of keeping the blisters covered until they crust over, handling disseminated zoster takes more care. It can be spread through the air as well as through direct contact with the fluid in the blisters, making it as infectious as varicella.
Consequently, it is recommended that patients with DCHZ be placed in negative airflow rooms. If one is not available, they should be quarantined in a closed room. Individuals without immunity to varicella should not enter the room.
A study conducted in West Virginia reviewed 29 cases of disseminated zoster. The study authors stated that shingles is considered a self-limited, localized infection among immunocompetent patients. “In contrast, patients with T-cell deficiency, such as HIV patients and bone marrow transplant recipients, can present with severe cutaneous and visceral disseminated disease,” they added.1
The authors reported that in close to 90% of the disseminated zoster cases they reviewed the patients initially presented with localized zoster first. It was followed by a secondary diffuse rash that helps to distinguish disseminated zoster from chickenpox.1
The study’s conclusions indicate that overall mortality and morbidity from DCHZ is low, and that it can occur in any immunocompetent host although it is more predominant among older patients.1
“Disseminated herpes zoster is a potentially serious infection that can present in the absence of immunosuppression,” its authors concluded.2 “Early diagnosis and aggressive treatment with intravenous acyclovir can reduce morbidity and severity of complications.”
1. Gomez E, Chernev I. Disseminated cutaneous herpes zoster in an immunocompetent elderly patient. Infectious Disease Reports. 2014. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4178270/.
2. Gupta S, Jain A, Gardiner C, Tyring SK. A rare case of disseminated cutaneous zoster in an immunocompetent patient. BMC Family Practice. 2005. https://bmcfampract.biomedcentral.com/articles/10.1186/1471-2296-6-50.