Boniform

The Diagnosis and Investigation of Shingles

by Sandhya


Differential Diagnosis
-The early prodrome stage of shingles can cause severe pain on one side of the lower back, chest, or abdomen before the rash appears. It therefore may be mistaken for disorders, such as gallstones, that cause acute pain in internal organs.

-In the active rash stage, shingles may be confused with herpes simplex, particularly in young adults and if the blisters occur on the buttocks or around the mouth. Herpes simplex, however, does not usually generate chronic pain.

-A diagnosis may be difficult if herpes zoster takes a non-typical course, such as with Bell's palsy (temporary paralysis on one side of the face) or Ramsay Hunt syndrome in the face, or if it affects the eye, or causes fever and delirium.

-The blisters of the shingles rash generally appear in the pattern of a band (dermatome) on one side of the body.

-In most cases shingles, the symptoms alone are sufficient to make a diagnosis. In some patients, such as those who are immunosuppressed, if the symptoms are not straightforward the physician performs one or more additional tests to detect the virus itself.


Tests to Identify the Virus

1. Virus culture

2. Tzanck Test

3.Immunofluoroscence Assay

4.Polymerase Chain Reaction (PCR)


1. Virus Culture
A viral culture uses specimens taken from the blister, fluid in the blister, or sometimes spinal fluid. The specimen is then sent to a lab where a culture in a petri dish is allowed to grow for a period of one and 14 days. It is also sometimes used in vaccinated patients to determine if a varicella-like infection is caused by a natural virus or by the vaccine.
**This test is useful, but it is sometimes difficult to recover the virus from the samples taken.

2.Tzanck Test
Test for the herpes simplex virus (which causes cold sores, fever blister, or genital sores), or varicella-zoster virus (which causes chickenpox and shingles).
The sore is scraped and the scraping is put on a slide and stained. The health care provider then examines it under a microscope.
Cells infected with the herpes virus will appear very large and contain many dark cell centers or nuclei.
**The test may help diagnose or confirm an infection with 1 of these 2 viruses . However, it’s unable to distinguish between these two viruses
**There is a high rate of false-negative results even when the virus is present



(the other two tests will be covered by Arma)

References
http://www.umm.edu/patiented/articles/what_tests_used_detect_chickenpox_shingles_000082_6.htm
http://www.clivir.com/lessons/show/shingles-virus-tests-and-diagnosis.html
http://health.allrefer.com/health/tzanck-test-pictures-images.html
http://www.free-health-care.com/skin_disorders/shingles.htm