[Risk factors related to allergic diseases at Mexico City]. / Factores de riesgo relacionados con enfermedades alérgicas en la Ciudad de México.

BACKGROUND: Several studies suggest that the prevalence of allergic diseases has been increasing worldwide in recent years; then it is very important to identify some risk factors that could be related. OBJECTIVE: To know some hereditary and environmental risk factors that could be related to the development of allergic diseases in open population from Mexico City. PATIENTS AND METHOD: It was an open-population, cross-sectional trial, in two phases with a random sample size of 4272 individuals in 214 public health centers. A questionnaire was applied by health workers. Statistical analysis was made with Excel 97-2004 using the Mann-Whitney U test for continuous variables and chi-square-test for discrete variables. p < 0.001 was considered statistically significant. RESULTS: The prevalence of allergic diseases in Mexico City was 42.6%, allergic rhinitis was the most frequent. The most important risk factors for allergic diseases were: family history of atopy in first and second degree; early consumption of cow's milk; early weaning with cereal, egg, beef, fish and pulses; living with some animals, indoor plants, active and passive smoking, to keep stuffed toys in the rooms, as well as living in dwellings with dust, cold temperatures, wall saltpeter and with dampness (mold growth). CONCLUSION: Because genetic factors can not be modified, it is important to identify environmental factors related to the development of allergic diseases in order to promote preventive measures.

[Prevalence of allergic diseases in Mexico City]. / Prevalencia de las enfermedades alérgicas en la Ciudad de México.

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.