YOUR HEALTH

DEAR DR. DONOHUE: Please discuss adult pertussis. I suspect it is often misdiagnosed and occurs more frequently than realized. -- R.C., D.O.

ANSWER: You're right, doctor. It is estimated that there are more than a million cases of pertussis (whooping cough) undiagnosed yearly in the United States. Worldwide, whooping cough is a major problem, causing 50 million infections and more than 40,000 deaths. Since the introduction of pertussis vaccine in developed countries, the number of cases has greatly fallen in those places, but there has been a resurgence in adults lately, probably because of the waning protection from vaccine that occurs with aging.

Whooping cough goes through three stages. In the first stage, which lasts one to two weeks, the symptoms are those of the common cold, with a runny nose, a low-grade fever and a slight cough. That stage evolves into the second stage, the paroxysmal stage. The cough becomes violent and occurs in outbursts of 20 or more successive, explosive coughs followed by a deep inhalation that makes a whooping sound. Stage 2 lasts two to four weeks. The third stage is the convalescent stage, during which cough and other signs and symptoms subside.

This picture is one typical of youngsters' infection. Adults don't go through these three stages. Their infection is one of a nagging, persistent cough that can last for two or more months. After a coughing fit, adults are left breathless and often throw up. Since whooping cough in adults is rarely thought of, the diagnosis is frequently missed.

Treatment of whooping cough is with antibiotics such as azithromycin, clarithromycin or erythromycin. The antibiotic doesn't always shorten the illness, but it does stop the spread of it. Adults younger than 65 ought to speak with their doctor about getting a pertussis booster shot.

DEAR DR. DONOHUE: What has happened to Reye's syndrome? When my daughter was a little girl, I heard about it constantly. Now I never hear about it. Why? -- L.B.

ANSWER: You don't hear much about it because Reye's syndrome cases are close to zero. Dedicated lay people, along with nurses and doctors, turned the tide against this potentially deadly illness by making it such an issue.

Reye's syndrome happens to young children who are given aspirin for a viral illness like the flu or chickenpox. As they begin to recover from the viral illness, they suddenly become quite ill again. They throw up and are very restless. Some drift into a coma, and a few die. Aspirin, coupled with the virus, damages the children's liver and brain. Now that the practice of giving aspirin to lower children's temperature has gone, so has Reye's syndrome.

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. 2006 North America Syndicate Inc. All Rights Reserved