Acute Herpes Zoster Infection
Etiology: “Shingles is caused by the varicella-zoster virus (VZV), the same virus that causes chickenpox. After a person recovers from chickenpox, the virus stays dormant (inactive) in the body. For reasons that are not fully known, the virus can reactivate years later, causing shingles.” CDC
Diagnosis
Diagnosis is clinical by seeing the distinctive, painful vesicular rash appearing in a unilateral, dermatomal distribution.
Use PCR (of vesicular fluid or of a swab of the base of an ulcer) to confirm atypical cases.
Associated conditions: Herpes Zoster Oticus (Ramsay Hunt syndrome when associated with facial nerve palsy).
Treatment
Treat acute shingles (with acyclovir, famciclovir, or valacyclovir) to decrease the duration of the rash if the patient can be treated within 72 hours of the onset of the rash. This will decrease the severity of the outbreak and may decrease the risk of persistent neuropathic pain.
Treatment can include topical corticosteroids and capsaicin cream, as well as oral pain medications.
Postherpetic Neuralgia
-Oral agents: Gabapentin, Pregabalin, and Amitriptyline
-Topical agents such as lidocaine patches and capsaicin cream or patches have been shown to reduce symptoms of postherpetic neuralgia.
Vaccination
Herpes zoster vaccine can prevent postherpetic neuralgia by reducing the incidence of herpes zoster but it has no role in the treatment of neuralgia.
**Shingles is also called zoster or herpes zoster. Shingles is caused by the varicella-zoster virus (VZV), the same one that causes chickenpox.
*Herpes zoster Oticus is caused by reactivation of VZV in the geniculate ganglion of the facial nerve.
Reference
https://www.cdc.gov/shingles/index.html
Postherpetic Neuralgia. N Engl J Med 2014; 371:1526-1533. http://www.nejm.org/doi/full/10.1056/NEJMcp1403062
Am Fam Physician. 2011 Jun 15;83(12):1432-1437. http://www.aafp.org/afp/2011/0615/p1432.html