Respiratory infections are more prevalent in children with a family history of atopy, as well as in younger children (two years of age or younger) who attend day care. Celedon and colleagues reviewed the relationship between day care attendance and respiratory tract illness in children attending day care during the first year of life.

Children were recruited if at least one parent had hay fever, allergies or asthma. Children born at 36 weeks of gestation (at least) to a mother who was at least 18 years of age were included in the study. After an initial screening telephone interview to the primary caretaker was completed (when the child was one month of age), a home visit was conducted, and a questionnaire was completed that included information about the child's environment, including smoke exposure. Telephone interviews were conducted every two months (beginning when the child was two months of age) to collect information about respiratory symptoms and illnesses experienced since the previous interview (e.g., ear infections, rhinorrhea, sinus problems, croup, bronchitis, bronchiolitis or pneumonia), day care arrangements, infant feeding and selected home characteristics.

Type of day care was classified as home (day care provider's residence), nonresidential (not provided at someone's home) and mixed. Potential allergen sources and respiratory irritants in the day care environment were considered. Daily and weekly length of attendance at day care and the presence of pets, carpeting and exposure to smoke at the day care facility were also registered.

Information collected in relation to the home environment included the number of months of breast-feeding, parental history of asthma or hay fever, exposure to smoking and demographic information. A multivariate analysis restricted to 238 children (47.8 percent of the 498 participants) who attended day care during the first year of life revealed that 67.7 percent (161) were in a home setting, 21.8 percent (52) were in a nonresidential setting and 10.5 percent (25) attended both. All 238 children attended day care for at least five hours per week, and almost one half attended at least three days per week for more than six months.

Children who attended day care were 1.6 times more likely to have a lower respiratory infection (e.g., croup, bronchitis, bronchiolitis or pneumonia), 2.2 times more likely to have sinusitis, 2.4 times more likely to have physician-diagnosed ear infections and 3.2 times more likely to have nasal catarrh than children who did not attend day care. When there were at least 10 other children in the day care setting, there was a 2.2-times higher risk of ear infections. The presence of any pet in day care was associated with 1.9-times higher odds, and the presence of a rug or carpet in the area where the child slept was associated with 3.2-times higher odds. Children attending nonresidential day care had a 2.9-times higher risk of two or more physician-diagnosed ear infections than those who attended day care in a home or who attended mixed day care.

The authors conclude that day care attendance during the first year of life (in children at high risk for atopy) was associated with a higher risk of upper and lower respiratory tract illnesses. Modifiable factors within the day care setting that are associated with a high risk of recurrent ear infections (in children with parental history of atopy) include the presence of pets or carpeting in the sleeping room.

editor's note: Many reasons are cited for placing small children in day care, but regardless of the reason, parents frequently experience guilt. This study offers guidance for parents with a history of allergies who must select among various day care options. It seems that of the possible day care options, a small home setting where the infant is not exposed to pets, smoking or carpeting in the sleeping areas is preferable to a larger, nonresidential day care facility. Physicians should offer this information to parents who must choose day care for their small children.—g.b.h.