A herpes virus.
Life. But not stress (PubMed).
Use of statins increases risk in a dose and time dependent fashion (PubMed). If you think losing a spouse is stressful instead as a reason for celebration, then stress does not increase the risk of shingles (PubMed).
And trauma; it may increase the risk for shingles (PubMed).
Autoantibodies to gamma interferon is a risk (Pubmed); patients act like HIV.
Viremia is the norm with shingles (PubMed). Shingles also increases risk of stroke, esp if there is eye involvement.
Giant cell arteritis of the aorta (Pubmed).
In pregnant, sero-negative females (not males) give VZIG within 96 hours of exposure to prevent disease.
Per the CDC, VZIG should be given to the following up 10 days after exposure; ideally within 96 hours:
"Patients without evidence of immunity to varicella (i.e., without a health-care provider diagnosis or verification of a history of varicella or herpes zoster, documentation of vaccination, or laboratory evidence of immunity or confirmation of disease) who are at high risk for severe disease and complications, who have been exposed to varicella or herpes zoster, and are ineligible for varicella vaccine, are eligible to receive VariZIG.. and includes
Neonates whose mothers have signs and symptoms of varicella around the time of delivery (i.e., 5 days before to 2 days after).
Premature infants born at ≥28 weeks of gestation who are exposed during the neonatal period and whose mothers do not have evidence of immunity.
Premature infants born at <28 weeks of gestation or who weigh ≤1,000 g at birth and were exposed during the neonatal period, regardless of their mothers' evidence of immunity status.
For shingles, add prednisone 60 mg/d for the first 7 days, 30 mg/d for days 8 to 14, and 15 mg/d for days 15 to 21, if lesions less than 72 hours to give more rapid resolution of the neuralgia.
Neurontin may be quite helpful with the pain. IL-2subcutaneous injections of 7.5 mIU bid for 5 consecutive days resolved post herpetic neuralgia in one patient (PubMed).
As I write this in the fall of 2017 there is a recombinant vaccine about to be released that is more effective.
The vaccine is approved for age 50 and above, and in the 50 to 59 year old group cuts shingles rates by 70% for the year following the vaccine, but the ACP maintains the policy to give to age 60 and above as of this writing (12/2011). What the long term protection of the vaccine is, well, time will tell, and can I coin a phrase? OK to given to patients on prednisone as long as <= 20 mg a day.
Not only is the vaccine safe (no cases) in patients with rheumatoid arthritis, psoriasis, psoriatic arthritis, ankylosing spondylitis, or inflammatory bowel disease including those on biologics, it also decreases the risk of zoster (PubMed).
Should you give the vaccine to someone with a recent case of shingles? Probably not, since the risk of recurrence is small (PubMed).
Depression leads to less response to the vaccine and treating depression restores response to vaccine (PubMed).
And there is one case of shingles from the vaccine strain in a normal host (PubMed).
Post herpetic neuralgia is awful (Review) and there are a variety of meds to try: Capsaicin, tricyclic antidepressants and neurontin are the list of drugs to try. As the review points out, "The only well-documented means of preventing postherpetic neuralgia is the prevention of herpes zoster. " That would be the vaccine.
Pneumonia is common in normal people with chicken pox, be very concerned if a pregnant woman gets chicken pox. With the vaccine, should be less of an issue.
If someone gets chickenpox more than once, then one the episodes had the wrong diagnosis.
Whilst those that have immunodeficiency have increased risk of shingles, the converse (and the nike) is NOT true. Maybe. Herpes zoster ophthalmicus had a 9.25-fold risk of a subsequent cancer diagnosis in the next year (PubMed).
Severe or multi-dermatomal shingles should, however, raise the issue of HIV. In the healthy elderly (> 60), the chicken pox vaccine decreases the incidence of shingles by 61% and post herpetic neuralgia by 67% (PubMed). The vaccine DID NOT cause the zoster, just in case you wanted to know.
The definitive link on prevention: http://www.cdc.gov/mmwr/preview/mmwrhtml/rr57e0515a1.htm. If you have a health care worker who is exposed and has no antibody, then needs to be removed from work 10 to 21 days after exposure. Patients are infectious 2 days before the rash until 4 days after the rash is crusted.
Curiously, in population studies, Zoster increases the risk of MS by 3.96, usually with 100 days. Why? Only speculation.