Rhinitis, in which the classification by etiology may be allergic or non-allergic, is a disorder characterized by inflammation of the mucous membranes lining the nasal passages. The symptoms of allergic rhinitis, which can be difficult to accurately distinguish from those of vasomotor rhinitis, typically include sneezing, nasal itch, rhinorrhea, nasal obstruction, post-nasal drip, and occasionally nasal pain. The prevalence of allergic diseases in Mexico City was 42.6%, allergic rhinitis was the most frequent. 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 anti allergic drugs. School and work annual absences are 3.37 +/- 3.86 and 6.2 +/- 12.84 days, respectively.
In any case, a normal CT scan and normal allergy testing in a setting of sino-nasal problems is highly suggestive of non-allergic rhinitis and treatment geared towards this diagnosis should be pursued. A majority of studies reported no serious adverse events associated with the use of antihistamines, cromolyn, or intranasal corticosteroids. Two prospective cohort studies demonstrate an increased likelihood of developing asthma over time in patients with allergic rhinitis, though no study was identified which addressed the question of whether treatment of allergic rhinitis can actually prevent the development of asthma. In addition, though the link between allergic rhinitis and rhinosinusitis is known, we identified no prospective studies on the outcomes of treated and untreated allergic rhinitis.