Two reports take aim at asthma jeopardy.

Two reports take aim at asthma jeopardy

Concerned by the rising rate of U.S. asthma deaths, a federal panel this week recommended ways to curb lethal episodes of the disease. At the same time, researchers reported evidence suggesting that a common mold can trigger potentially catastrophic airway constriction in some asthma suffers.

The scientific panel, convened by the National Heart, Lung, and Blood Institute in Bethesda, Md., urges physicians who treat the nation's 10 million asthma patients to prescribe drugs that target the underlying inflammation of the lung's bronchial tubes, instead of relying primarily on the short-term breathing relief provided by inhaled bronchodilator drugs. Recent reports have suggested that overuse of bronchodilators may encourage progression of the disease, perhaps contributing to the rise in asthma death rates (SN: 12/15/90, p.373).

The panel also recommends that asthma sufferers reduce their exposure to indoor and outdoor allergens, such as dust, pollen and mold spores. These tiny particles can precipitate the airway constriction of an asthma attack. A severe astma attack can escalate into a life-threatening respiratory arrest if the bronchial tubes close up enough to block the patient's breathing.

The cautionary advice on allergens dovetails with a report in the Feb. 7 NEW ENGLAND JOURNAL OF MEDICINE by Martin I. Sachs and his colleagues at the Mayo Clinic in Rochester, Minn. The researchers found a 200-fold increase in the risk of potentially lethal respiratory arrest among asthmatics who react to the mold Alternaria alternata, compared with asthmatics who show no heightened sensitivity to it.

"One of the factors which appears capable of causing the muscle in the airway to clamp down is exposure to that allergenic mold," Sachs told SCIENCE NEWS.

The team reviewed the medical records of 11 males and females, aged 11 to 25, who had experienced respiratory arrests between 1980 and 1989. The analysis revealed that 10 of the 11 asthmatics showed an allergic reaction to A. alternata in skin-prick tests. In contrast, only 31 of 99 asthmatics in the study's control group showed sensitivity to the mold.

A. alternata grows on harvested corn and other grains, and is particularly common in the Midwest from June through November, says Sachs. Allan T. Luskin, an immunologist at the University of Illinois at Chicago, notes that the ubiquity of environmental allergens underscores the importance of controlling the chronic inflammation of asthma, and thus reducing the riskiness of an allergic encounter.