DEAR DR. DONOHUE: I have been struggling with bladder infections for the past two years. It started with trich. I have had a hard time getting rid of it because I am allergic to Flagyl. It gives me hives on my right wrist. I have the need to urinate frequently. I am so frustrated. What do you think is going on? – C.D.

ANSWER: Something in your story doesn’t add up. Trich – trichomonas (TRICK-oh-MOAN-us) – is a vaginal infection. It doesn’t cause bladder infections.

A trich vaginal infection causes a malodorous, often yellow vaginal discharge. Proof that the infection is due to trich can be had by finding the trich organism in a microscopic examination of the discharge.

Flagyl is the standard medicine used to treat such an infection. If the hives on your wrist were truly due to an allergic reaction, you and your doctor have to come to a decision about re-treatment with that medicine. Perhaps an antihistamine taken concurrently will stop the hive outbreak. Flagyl usually works. If you happen to have a trich infection that is resistant to Flagyl, your doctor can obtain from the Food and Drug Administration another medicine called tinidazole. It is in use in many other countries. It has not yet been given approval for general use in the United States.

Bladder infections have different symptoms. They cause painful urination and a need to frequently empty the bladder. They don’t usually cause a vaginal discharge. Therapy for recurrent bladder infections hinges on finding which bacterium causes them and what drugs are effective against that bacterium. Sometimes, a doctor gives a woman with repeat infections an antibiotic to keep on hand. The woman treats herself for three days when signs of the infection occur. Or the doctor can put a woman on continuous low-dose antibiotic.

Frequent bladder infections can also be related to intercourse. If they are, then the woman can take an antibiotic after having relations. Or they might be the result of an anatomic abnormality that calls for surgical correction.

Vaginal infections are common female illnesses. The pamphlet about those infections discusses causes and cures. Readers can order a copy by writing: Dr. Donohue – No. 1203, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.50 U.S./$6.50 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: I was diagnosed with Achilles tendinitis three years ago. My doctor said it would go away in six months. Well, I still have it. Any suggestions to make life more bearable for me would be appreciated. – B.H.

ANSWER: The Achilles tendon (heel cord) connects the calf muscles to the heel. The muscles and their tendon lift the back of the foot off the ground.

Achilles tendinitis is an inflammation of the tendon or a degeneration of its collagen fibers.

Overuse is the usual cause of the problem. Rest is its cure. Anti-inflammatory medicines – Advil, Aleve, Motrin, etc. – speed recovery. A 3/8-inch heel lift inserted in the shoe provides rest for the tendon when a person is up and walking about.

Your story is most unusual. The problem doesn’t usually last as long as yours has. Why not seek a second opinion? Something else might be the cause. Also ask the doctor if a physical therapy program would benefit you and your tendon.

DEAR DR. DONOHUE: What are the symptoms of Paget’s bone disease? – S.M.

ANSWER: Bones undergo constant remodeling. With Paget’s disease, the normal breaking down and building up of bone is out of whack. The breaking-down process accelerates. The building-up process tries to match the acceleration, but it produces misshapen and weak bones.

Many Paget’s patients have no symptoms. When symptoms appear, they are bone pain, bone deformity or broken bones from minor trauma. Another tip-off for Paget’s disease is a high level of blood alkaline phosphatase, an enzyme found in bones.

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.