WASHINGTON (Reuters) - Cockroaches worsen asthma symptoms in children far more than furry pets or dust mites, U.S. researchers reported on Tuesday. High-rise apartments in Northeastern U.S. cities were the worst places for the allergic effects of cockroaches, the team at the University of Texas Southwestern Medical Center in Dallas found. Single-family houses were the worst for dust mites -- miscroscopic creatures that live in bedding and furniture. "We found that a majority of homes in Chicago, New York City and the Bronx had cockroach allergen levels high enough to trigger asthma symptoms, while a majority of homes in Dallas...