The NERVE! Chickenpox Returns as Shingles

I’m prompted to write this having seen a new case of shingles each week for the past month – not too surprising with 1 million cases occurring yearly in the US. Since we have treatment that works better the sooner the patient seeks care, it’s important for people to recognize it.

The varicella zoster virus causes chickenpox when the body sees it for the first time – that childhood rash that covers a child’s body at the most inconvenient times – or at least used to before the childhood varicella vaccine was available. After the initial illness, the virus stays dormant in the sensory nerves, and at times, reappears as zoster or shingles – a painful rash usually involving only one nerve’s distribution area. Most often, it is on the trunk, in the shape of a fairly horizontal stripe around one side of the body, from midline chest or abdomen to midline back, but it can appear on the face or on the extremities. On the arms or legs, the ‘stripe’ is more vertical. If the area around the eye is involved, it can result in vision loss, so it needs to be evaluated immediately by an ophthalmologist.  More about that later.

Classically, the rash starts as red spots and advances to clusters of blisters on a red base. The associated pain or neuritis is usually described as stabbing, burning or throbbing, and often precedes the rash by a day or two. Many diagnostic tests, and even surgery, may be done searching for the cause of the pain, until the rash appears – then the diagnosis is clear. This initial pain is felt to be due to viral replication and from inflammation from your own white blood cells, leading to nerve damage and increased sensitivity to pain. The description of the pain, including irritation when just touching the skin, raises the suspicion for this diagnosis. With a normal immune system, the lesions usually crust over by 7-10 days. Less than 20% of patients have flu-like symptoms with headache, fever, fatigue and achiness at the beginning.

Can someone ‘catch’ shingles from you? No, but someone who has never been exposed to chickenpox or the varicella vaccine, or someone who is immunocompromised, can get chickenpox from being in contact with the fluid from the blisters. So it’s important to cover the rash until the lesions are scabbed over.

By far, the most common complication and the dread associated with this illness is ‘post-herpetic neuralgia’ (PHN) – which, by definition, is pain that lasts at least 3 months after an episode of shingles. It can be very severe. My patients who are most anxious to be vaccinated against it are those who know people who have had PHN. The incidence of PHN increases with age – ranging from 5% in those under 60 years old to 20% in those over 80. Fortunately, a vaccine to decrease the risk of shingles is available.

Other complications of shingles include bacterial infection of the skin lesions, especially with staph or strep, eye or ear involvement, or meningitis. Headache and skin lesions on the nose are often signs that the eye can become involved. This requires immediate attention from an ophthalmologist, and is treated with oral antivirals as well as eye drops. Rarely, motor nerves can be involved by shingles, causing muscle weakness.

The risk for getting shingles increases with age; others at increased risk are those with a compromised immune system, including HIV, lymphoma, leukemia, chemo or transplant patients, those with lupus, rheumatoid arthritis, Crohn’s or ulcerative colitis, asthma, insulin dependent diabetes, chronic lung or kidney disease, or depression. According to a study just published in the British Medical Journal, these diagnoses are especially important in those under 50, which is usually considered a lower risk group for shingles. The medications used to treat many of these illnesses include oral and inhaled steroids or immunosuppressants, which also contribute to the risk. The irony is that the shingles vaccine (Zostavax) is an attenuated live virus. It can make immunocompromised patients ill, so the very patients who need the vaccine the most cannot safely take it. Hopefully in the future, we’ll have an alternate risk reduction strategy in this population.

The shingles vaccine (ZostaVax) was introduced in 1995 and is licensed to be given to those over 50 years old, but recommended by the CDC for those over 60. It is a one-time dose for now, and is covered by Medicare Part D (not Part B) and by many private insurance companies for those over 60. It decreases the incidence of shingles by 50% in general (by 70% in 50-59 year-olds, 64% in 60’s, 41% in 70’s and 18% in 80’s) and decreases PHN by 67%. Because chickenpox was so prevalent when the current 50 year olds were growing up, 99% of that adult population has been exposed, even if they didn’t have an obvious case of chickenpox. Therefore, testing for prior exposure is not necessary unless certainty is needed, as in health care workers or pregnant women, who would need to receive the chickenpox (varicella) vaccine if they are part of the “1 percent” who truly weren’t exposed.

Although second episodes are said to be rare, I’ve seen it often enough so that it can’t be too rare. In fact, even if someone has had shingles, there’s an official recommendation to still have the vaccine to prevent another occurrence. Other than waiting for the rash to resolve, there is no set time to wait before giving it. In my own practice I usually wait a few years, assuming that the patient’s own immunity is revved up for a while from the actual illness. Those who are allergic to the vaccine components, including gelatin or neomycin, should not receive it. Some people get a rash near the vaccine site. As a precaution the CDC recommends covering it until it disappears. There is no documentation of a person getting chickenpox from someone who has received the shingles vaccine. Some people do get shingles even after they’ve had the vaccine, but it is usually a milder than average case.

The incidence of shingles has been increasing over the past few decades. One theory was that since children are being vaccinated against chickenpox and not getting the illness themselves, adults aren’t repeatedly exposed to it and so are not increasing their antibodies. Those antibodies would keep varicella-zoster virus get out of control as shingles. However, the rate had been increasing prior to the introduction of the varicella vaccine in 1996 and didn’t increase more after that introduction. So it’s not clear why the rate has increased, other than more frequent use of immunosuppressant medications for many other illnesses, putting more people at risk.  Most patients I see with it, though, don’t have any particular risk factor.

Fortunately, we now have treatment that can speed the resolution of the skin lesions and the acute pain compared with no treatment; some studies show shorter duration of PHN as well. Acyclovir (Zovirax), famcyclovir (Famvir) and valacyclovir (Valtrex) all work well. The main advantage of the last two are that they are taken three times a day, versus five times daily for acyclovir. They should be started as soon as possible within 72 hours of the onset of rash, or later if new lesions are still appearing. Immunocompromised hosts or others with many lesions outside the main area of rash may be hospitalized for intravenous therapy.

Treatment for the pain may start with anti-inflammatories like ibuprofen or naproxen, and/or acetaminophen (Tylenol). If stronger medication is needed, your physician might choose to use tramadol or codeine or one of its synthetic forms, or medications that are used for nerve pain – gabapentin (Neurontin), pregabalin (Lyrica) or amitriptyline – especially for longer-lasting pain. These can be effective but do have side effects, especially in the elderly and at higher doses.

So, shingles is a common illness that for some is just an annoyance but for others a very long, painful experience. For more information, go to the CDC website and ask your doctor about whether the vaccine is right for you. Stay well!!

REFERENCES:

Some pharmaceutical companies provide vaccines to eligible adults who cannot afford them. For information on the patient assistance program that includes Zostavax (shingles vaccine), see www.merck.com/merckhelps/vaccines/home.html.

http://www.cdc.gov/shingles/about/overview.html

www.uptodate.com

Quantification of risk factors for herpes zoster: population based case-control study
BMJ 2014; 348 doi: http://dx.doi.org/10.1136/bmj.g2911 (Published 13 May 2014)