DEAR DR. DONOHUE: Before having plastic surgery, I had to have a physical examination and various blood tests. Everything was normal except for my platelet count, which was low. Surgery was cancelled. I then saw a blood specialist, who says I have idiopathic thrombocytopenic purpura. “We are going to watch things.” I’m not so sure I want to sit around and watch things. What would you do? – S.C.

ANSWER: Platelets have another name, thrombocytes (THROM-boh-sites). They seal broken blood vessels with a clot. The “penic” of idiopathic thrombocytopenic purpura indicates a deficiency of platelets; “purpura” means “bruises,” the consequence of having too few platelets; and “idiopathic” signifies that the cause is unknown. A newer name for this disease is immune thrombocytopenic purpura. The new name puts emphasis on the immune system as singling out platelets for an attack and destruction.

The normal platelet count lies between 150,000 and 400,000. Counts of 30,000 to 50,000 are admittedly low, but they don’t usually call for immediate action. Watchful waiting is the position often adopted, and I bet your count falls in this range. When the count drops below 10,000, there’s a greater urgency to begin treatment. If a person, regardless of how low the count has dropped, is bleeding, then therapy is begun.

Prednisone, one of the cortisone drugs, is usually the drug of first choice. Intravenous immunoglobulin (gamma globulin) or anti-Rh D factor globulin (the same Rh factor screened for in pregnant women) are other effective treatments. When medicines fail to raise the platelet count, spleen removal almost always can boost it; the spleen removes platelets from circulation.

You have no current symptoms. You have no bruises. You’re in no danger of bleeding. Your doctor’s approach is sensible.

Childhood immune thrombocytopenic purpura is a different story.

DEAR DR. DONOHUE: I am proud to be a senior citizen in excellent health. I take no medicines. I do take a daily dose of cod liver oil. My mother gave all us children cod liver oil. There were 10 of us. I kept up the practice, and I believe my good health can be attributed to it. Now with all the talk of mercury contamination of fish, I wonder if I should stop. Should I? – G.B.

ANSWER: You face no danger of mercury poisoning from cod liver oil. However, it does contain a large amount of vitamin A. The recommended daily dose of vitamin A is 900 micrograms (3,000 IU) for men, and 700 micrograms (2,330 IU) for women.

The upper daily safe amount of vitamin A is 3,000 micrograms (10,000 IU). Check the label on your cod liver oil for its vitamin A content. Some cod liver oil preparations contain 1,360 micrograms (4,500 IU) of the vitamin in one teaspoon. If you’re taking a tablespoon, you’re over the safe limit. Or if you take a multivitamin containing A, you’re nearing the toxic limit even with one teaspoon. High doses of vitamin A promote osteoporosis.

Furthermore, vitamin A is a fat-soluble vitamin. That means the vitamin stays in body fat for long periods.

Most authorities discourage daily doses of cod liver oil.

DEAR DR. DONOHUE: I am nursing my first baby, and I have come down with a breast infection. My doctor has me on antibiotics, and he said I can continue to nurse. Do you think I should continue nursing? – A.F.

ANSWER: Breast infections happen to as many as 3 percent of nursing mothers. So long as your doctor says you can and so long as you are not in great pain, then I don’t see any reason to stop. If the doctor changes his opinion and tells you to stop, you can continue to promote milk production by using a breast pump.

Breast milk is the most natural and nourishing food a baby can get.

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.