DEAR DR. DONOHUE: I am not getting a flu shot this year. Last year I did, and I got the flu a couple of days later. I’ll take my chances this time.

I’m not the only one who had this happen. Why don’t the authorities tell people that the shot might make them sick? Are they in league with the drug companies? – R.B.

ANSWER: What were your symptoms after you got the shot? Many people say they had the flu when they really didn’t. Flu, or influenza, strikes suddenly. One minute people feel good; the next minute, they feel terrible – so terrible they want to go to bed and stay there without any interruptions. Temperature rises.

Muscles hurt. Headaches are common. They have a dry cough and a scratchy throat. Real flu is not a stomach illness. It doesn’t cause diarrhea. That’s an illness many refer to as intestinal flu, but it’s not influenza and is not what the flu shot protects against.

The flu vaccine contains dead virus. It is impossible for it to cause flu.

In an extremely small number of people, the vaccine can cause chills, fever and headache within 12 hours of getting the shot, but the symptoms disappear in one or two days.

If you did have the real flu after getting the shot, you were incubating that illness when you received the vaccine.

It takes two weeks for the body’s production of antibodies against the flu virus to reach a protective level.

Not to overdramatize it, but influenza can kill, and it does so most often in older people, those 65 and older.

I don’t think anyone should face a flu season without having the protection of the vaccine.

DEAR DR. DONOHUE: My daughter started school this year. It was traumatic for her at first, but she has adapted well and now likes it.

I think she has pinworms. She scratches her behind all the time. This is traumatic for me. How do I know for sure, and how do I get rid of them if she does have them? – N.O.

ANSWER: Pinworms are a common childhood (and adult) infection, and outbreaks of them often occur at the start of the school year.

The worms live in the digestive tract. At night, the female pinworm journeys down the colon and out of the anus to lay eggs in the surrounding skin. Infective larvae hatch in about six hours. The eggs and larvae cause a reaction that promotes intense itching. Scratching traps eggs and larvae under the fingernails, and that’s how the infection is transferred to another – the touch of an infected child to another child or adult.

The worm is small, about two-fifths of an inch long, barely visible. The eggs are even smaller. A doctor with a microscope can identify the worms or the eggs more easily and confidently than you can.

Furthermore, you need a prescription for pinworm medicine, so a trip to the doctor is inevitable.

Vermox is the medicine most often used. Albenza is another effective medicine. The entire family is treated. Washing clothes, bed linens and towels in the hot cycle of the washer kills worms and eggs.

Clipping an infected child’s fingernails prevents entrapment of the worms and eggs there, and stops destructive scratching.

DEAR DR. DONOHUE: I am concerned about the radiation from MRI scans. I have had three scans. How much radiation did I get from them? – L.M.

ANSWER: None. MRI scans create pictures of internal structures using magnets that cause a brief rearrangement of atoms in the body.

The rearrangement creates energy that produces the images. You need not concern yourself about any radiation damage.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com.