Herpes zoster laboratory tests
|
Herpes zoster Microchapters |
|
Diagnosis |
|---|
|
History and Symptoms |
|
Treatment |
|
Case Studies |
|
Herpes zoster laboratory tests On the Web |
|
American Roentgen Ray Society Images of Herpes zoster laboratory tests |
|
Risk calculators and risk factors for Herpes zoster laboratory tests |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], L. Katie Morrison, MD; Associate Editor(s)-in-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Laboratory Findings
If the rash has appeared, identifying this disease (making a differential diagnosis) only requires a visual examination, since very few diseases produce a rash in a dermatomal pattern (see map). However, herpes simplex virus (HSV) can occasionally produce a rash in such a pattern. The Tsanck smear is helpful for diagnosing acute infection with a herpes virus, but does not distinguish between HSV and VZV.[1]
When the rash is absent (early or late in the disease, or in the case of zoster sine herpete), herpes zoster can be difficult to diagnose.[2] Apart from the rash, most symptoms can occur also in other conditions.
Laboratory tests are available to diagnose herpes zoster. The most popular test detects VZV-specific IgM antibody in blood; this only appears during chickenpox or herpes zoster and not while the virus is dormant.[3] In larger laboratories, lymph collected from a blister is tested by the polymerase chain reaction for VZV DNA, or examined with an electron microscope for virus particles.[4]
In a recent study, samples of lesions on the skin, eyes, and lung from 182 patients with presumed herpes simplex or herpes zoster were tested with real-time PCR or with viral culture. [5]. In this comparison, viral culture detected VZV with only a 14.3% sensitivity, although the test was highly specific (specificity=100%). By comparison, real-time PCR resulted in 100% sensitivity and specificity. Overall testing for herpes simplex and herpes zoster using PCR showed a 60.4% improvement over viral culture.
References
- ↑ Oranje AP, Folkers E (1988). "The Tzanck smear: old, but still of inestimable value". Pediatr Dermatol. 5 (2): 127–9. PMID 2842739.
- ↑ Chan J, Bergstrom RT, Lanza DC, Oas JG (2004). "Lateral sinus thrombosis associated with zoster sine herpete". Am J Otolaryngol. 25 (5): 357–60. PMID 15334402.
- ↑ Arvin AM (1996). "Varicella-zoster virus" (PDF). Clin. Microbiol. Rev. 9 (3): 361–81. PMID 8809466.
- ↑ Beards G, Graham C, Pillay D (1998). "Investigation of vesicular rashes for HSV and VZV by PCR". J. Med. Virol. 54 (3): 155–7. PMID 9515761.
- ↑ Stránská R, Schuurman R, de Vos M, van Loon AM. (2003). "Routine use of a highly automated and internally controlled real-time PCR assay for the diagnosis of herpes simplex and varicella-zoster virus infections". J Clin Virol. 30 (1): 39–44. PMID 15072752.