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Shingles and postherpertic neuralgia A005
Current RMA Instruments
|Reasonable Hypothesis SOP||27 of 2023|
|Balance of Probabilities SOP||28 of 2023|
Changes from previous Instruments
Shingles, also known as Herpes zoster, is a painful, self-limiting skin (or mucous membrane) rash on part of one side of the body. It is due to reactivation of latent Varicella-Zoster virus, which has been lying dormant in the nervous system following an earlier chicken pox infection. Postherpertic neuralgia is pain that persists for months or years after the resolution of a shingles rash, in the same area as the rash. In rare cases the pain may first develop months to years after the resolution of the shingles rash.
Confirming the diagnosis
Diagnosis is usually made on the clinical presentation. The virus can be detected on testing of vesicle fluid or on serology. The relevant medical specialist is an infectious diseases physician, but a specialist report will not generally be required.
Additional diagnoses covered by these SOPs
- Herpes zoster
- Ramsay Hunt Syndrome
- Vaccine strain Herpes zoster
- Zoster ophthalmicus
Conditions excluded from these SOPs
- Chicken pox* - Chicken pox SOP
- Cold sores* - Herpes simplex SOP
- Genital herpes* - Herpes simplex SOP
- Herpes simplex I or II* - Herpes simplex SOP
- Varicella* - Chicken pox SOP
* another SOP applies.
Clinical onset for shingles will be at the time of onset of the rash. For postherpetic neuralgia the onset will generally be when the rash resolved (but the pain persisted). In some cases onset of the pain may be well after the shingles rash has resolved.
If clinical worsening is being considered an opinion from an infectious disease physician should generally be sought, on whether there has been an enduring clinical worsening out of keeping with the natural history of the condition.
Further notes and comments
Following a chickenpox infection, the varicella zoster virus remains latent in nerve cell bodies of the dorsal root, cranial nerve or autonomic ganglia. Years or decades after the initial infection, the virus may reactivate and cause infection of the skin (or mucous membrane) in the region supplied by the nerve (a dermatome). The infection causes a painful rash with vesicles (small blisters). The rash usually heals within two to four weeks, but some sufferers may experience residual nerve pain for months or years (postherpetic neuralgia). The infection can involve the face, mouth, eye or tongue.
Reactivation of the latent infection generally occurs when the immune system becomes compromised. Recurrent episodes of shingles/ Herpes zoster are rare except in immunosuppressed patients.