Childhood asthma in Thailand.

Asthma is common in Thai children with a prevalence of about 4%. A prospective study of 2,000 Thai asthmatic children showed boys to be more frequently affected than girls, and fifty percent of patients experienced their first attack within the first 2 years of life. Attacks usually occurred in winter and the rainy season. 63.15% of patients had asthma associated with other allergic diseases and 79.25% had a family history of allergic diseases. Positive skin tests to important antigens were noted in 93.7% of cases, and house dust was the most common. Pharmacokinetic studies of theophylline were made in Thai asthmatic children after oral administration revealed that the elimination half-life of theophylline was longer than that observed in subjects in Western countries. Long-term follow up of 247 Thai asthmatic children revealed that in 37.2% of patients, symptoms ceased at the age of 15 years. The factors which indicated a favorable prognosis included male sex, mild or moderate illness, negative skin tests or positive skin tests to only a few allergens.