Maternal smoking during pregnancy (MSP) and exposure to tobacco smoke are associated with increased morbidity in asthmatic children. It is not clear how to protect effectively asthmatic children from parental smoking.
We considered 98 young children with persistent asthma for a period of 12 months (mean age 3.5 y±0.5; 56 M/42 F). 64 had non smoking parents (NSP), 15 had indoor smoking parent (ISP) and 19 outdoor smoking parent (OSP). 10 children had been exposed to MSP, among which 6 had ISP.
Children exposed to ISP had more days in hospital because of asthma (4.6±5), than children with NSP (1.9±4.6, p = 0.05), and OSP (0.7±2, p = 0.005). Children with ISP had more asthma related ER admissions (1.6±1.5) than children with NSP (0.8±1.1, p = 0.03), and OSP (0.4±0.6, p = 0.007). Children with ISP had more pneumonia (2.1±2.1) than children with NSP (0.7±1.1, p = 0.001) and OSP (0.6±1.1, p = 0.01). MSP showed no significant association with days in hospital, ER admissions, pneumonia. Children with ISP had worse symptom score (1.66±0.6) than children with OSP (1.36±0.6, p = 0.06), and NSP (1.13±0.4, p = 0.0002). Children with MSP had worse symptom score (1.7±0.7) than children non exposed (1.2±0.4). No relation was found between parental smoking and FEV1 and FEF 25–75 in these children.
We conclude that in this population, OSP was associated less morbidity and better asthma control than ISP. Advising smoking parents to smoke outdoors may improve asthma morbidity and control in young children.