DEAR DR. ROACH: Can exposure to infectious mononucleosis trigger or cause rheumatoid arthritis to flare up and become active? I would appreciate your comments. Thank you. – J.C.

ANSWER: The Epstein-Barr virus – the cause of infectious mononucleosis (although there are other germs that can cause a similar picture) – has been associated with rheumatoid arthritis, and there is some evidence that EBV may be a trigger that causes RA and possibly other autoimmune diseases, such as lupus, to become active in a person who is genetically susceptible. However, this evidence is only speculative at this point, since an alternative explanation for the association is that the immune deficiencies in RA and other autoimmune diseases allow for abnormal persistent replication of EBV.

What is more important is that nearly all adults (90-95 percent) have had EBV infection, and re-exposure to the virus does not cause clinical infection and almost certainly will not trigger new onset or a flare-up of RA in people who already have been exposed to EBV.

DEAR DR. ROACH: I have never had the shingles, nor even chickenpox. I couldn’t find a record of it, even in my baby book. Do I need to have the shingles shot? I am over 70 and take several medications for high blood pressure and cholesterol. – C.S.

ANSWER: I recommend the shingles vaccine to someone in your situation, despite the fact that the shingles vaccine isn’t perfect. In the initial trial that got the vaccine approved, following almost 40,000 adults over 60, 3.3 percent who did not receive the vaccine got shingles in three years, and 1.6 percent of those who received the vaccine developed shingles. However, for the dreaded complication of post-herpetic neuralgia, having the vaccine reduced the risk from 0.6 percent to 0.2 percent in people over 70.

Most people over 70 have had chickenpox. Sometimes the disease is so mild that it can go unrecognized. But both people who have and have not had chickenpox should get the vaccine. People with conditions weakening their immune system should not get the vaccine.

The absolute benefits of 1.7 percent reduction in developing shingles, plus the 0.4 percent reduction in post-herpetic neuralgia are not very large. About 50 people would need to be vaccinated to prevent one bad outcome in three years. Over a long time, however, the absolute benefit is likely to get more impressive.

More importantly, the risk of the vaccine is small. The major adverse events have been headache and sore arm. In my opinion, the benefits far outweigh the risks, and by vaccinating a lot of people, some cases of shingles and post-herpetic neuralgia can be prevented. Having seen how devastating post-herpetic neuralgia can be in an older person, I think it is worth it.

DEAR DR. ROACH: In your recent column on Achilles tendinopathy, you discuss treatment, but please also make sure that the patient does not have a spondyloarthropathy. – Dr. Irene Blanco, M.D.

ANSWER: The spondyloarthropathies are a group of related conditions, including ankylosing spondylitis, psoriatic arthritis and reactive arthritis (formerly called Reiter’s syndrome). These all increase the risk of Achilles tendinopathy, due to inflammation at the insertion of tendons to bone. Similarly, these conditions also increase the risk of plantar fasciitis. Achilles tendinopathy and recurrent plantar fasciitis should prompt your doctor to consider the possibility of one of the spondyloarthropathies. X-rays and blood tests help confirm the clinical diagnosis.

I thank Dr. Blanco for writing.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Health newsletters may be ordered from www.rbmamall.com.