[Prevalence of allergic diseases in Mexico City].

Background: There is a considerable variation in the prevalence of allergic disorders in developing countries. These differences may be attributable to different methodological problems and to the lack of operational definitions. Several studies suggest that the prevalence of allergic diseases has been increasing worldwide in recent years. However, in Mexico, there is no data in open population.

Objective: To know in open population the prevalence of allergic diseases in the counties of Mexico City, the frequence of symptoms in each allergic disease, the therapeutic modalities that patients seek, the school and work annual absences and the amount of money that each patient spends in antiallergic drugs.

Patients And Methods: It was an open-population, cross-sectional trial, in two phases with a random sample size of 8,000 individuals from 214 public health centers. Statistical analysis was made with Excel 97-2004: Mann-Whitney U test for continuous variables and chi-square-test for discrete variables, p < 0.05 was considered statistically significant.

Results: The prevalence of allergic diseases in Mexico City was 42.6%, allergic rhinitis was the most frequent. Children are the largest age group affected. The highest prevalence was found in Tlahuac county. Coexistence of allergic diseases was found in 19.9%. The 44.2% of allergic patients attended to their general practitioner. 20.4% of all patients spent 10-20% of their income in medicines and 26% do not have money to buy antiallergic drugs. School and work annual absences are 3.37 +/- 3.86 and 6.2 +/- 12.84 days, respectively.

Conclusion: Allergic diseases must be considered a public-health problem in Mexico City.