Pediatric asthma hospitalizations are higher in the fall months than any other season. The summer months have the lowest rate of asthma hospitalizations. Between 1986 and 1999 the median monthly total asthma hospitalizations were lowest in July (37 in Baltimore and 63 in the remainder of Maryland) and highest in October (169 in Baltimore, 289 in the rest of Maryland). The frequency of asthma admissions rises most dramatically from Summer to Fall months (weeks 26 to 35) in all age groups.(Blaisdell, Univ. of Maryland, 2001)

The seasonal characteristics of asthma hold true across urban and nonurban areas.(Blaisdell, Univ. of Maryland, 2001)

Despite high ozone levels in Baltimore during the summer months, from 1986 to 1999 the frequency of pediatric asthma hospital admissions were lowest in the summer. This does not negate the potential role of ozone in respiratory disease, however, ozone alone does not explain the seasonal variability of pediatric asthma hospital admissions.(Blaisdell, Univ. of Maryland, 2001)

Understanding the seasonal patterns of asthma hospitalizations, as they have been uncovered by the work of Dr. Carol Blaisdell at the University of Maryland Medical Center, is useful for patient management, especially to alert individual asthmatic patients, their parents, and public health officials to periods of increased risk.