DEAR DR. DONOHUE: I have a very severe case of psoriasis. My entire body is affected. I have had it for many years, but not this bad. I have tried many different creams and lotions, but nothing is helping. Is there some kind of pill I could take? – R.K.

ANSWER: You’re not alone. Up to 3 percent of the world’s population suffers from psoriasis. It’s a lifelong affliction, with cycles when it improves followed by cycles when it gets much worse. Fortunately you are living at a time where the number of treatments for it have burgeoned.

Ordinarily it takes a month for the lowermost skin cells to reach the skin surface. That gives them time to mature. With psoriasis, the lowermost cells reach the surface in three to five days. These immature cells produce the red patches covered with silver scales so typical of psoriasis. The immune system is somehow involved in the process, prodding skin cells to cut short their period of maturation. The immune system also causes a release of chemicals that damage skin.

Psoriasis medicines that can be applied directly to the skin include cortisone drugs like Synalar or Aristocort. They come as creams, ointments, gels or lotions, and they control the process for many. Dovonex, which is related to vitamin D, is another skin-applied medicine, as is Tazorac, which belongs to the vitamin A family.

Ultraviolet B light can sometimes keep psoriasis in check. Ultraviolet A light, coupled with the oral drug psoralen, is another effective treatment. It might, however, lead to skin cancer for a few.

Oral drugs include methotrexate and cyclosporine. Soriatane is also taken by mouth. It’s related to a powerful acne drug and cannot be taken before or during pregnancy.

There are new treatments called biologic agents. They act against a misbehaving immune system and keep it under wraps. Examples include Amevive, Raptiva and Enbrel. They’re given by injection, and they represent a new era in psoriasis treatment.

DEAR DR. DONOHUE: I read that a doctor believes the cause of acid reflux is not having enough stomach acid and that sufferers should take hydrochloric acid rather than antacids. Would you comment? – I.S.

ANSWER: I don’t know a single doctor who subscribes to that theory, including me.

Acid reflux – heartburn – comes from the upward spouting of stomach acid and digestive juices into the esophagus, which was not designed to cope with them as the stomach can.

Antacids neutralize stomach acid. Medicines such as Tagamet, Zantac, Axid and Pepcid decrease stomach acid production. Prilosec, Nexium, Prevacid and Aciphex turn off acid production. If you need a medicine, stick with one of these.

The booklet on hiatal hernia, heartburn and acid reflux presents this story in full. To obtain a copy, write to: Dr. Donohue – No. 501, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.75 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: I came in contact with a person who tested positive for TB on the PPD test. X-rays of the lungs were negative. What should I do? What meds do I take if I have the same results? – S.L.

ANSWER: Having a positive skin test for TB – the PPD skin test – is not evidence that a person has active TB that can be spread to others. It means that the person has a TB germ in the body that has been walled off in a sort of coffin. Many people who have a positive reaction are put on one TB drug, INH. It’s prescribed to prevent the TB germ from rising from its coffin later in life and giving the person active tuberculosis.

An active case of TB is proved with a chest X-ray consistent with infection and by finding the TB germ in the person’s sputum. Every doctor knows that all active cases must be treated, both for the patient’s health and for the health of the public.

I am positive that the person you came in contact with does not have active TB. If he or she does, someone is guilty of malpractice.

You don’t need to do anything. Mention it to your doctor, who, I am sure, will agree with me.

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.