Patient description: A 4 year old boy presents to the emergency room with wheezing. He has had a history of allergic rhinitis, but no history of wheezing. His mother reports that 5 hours ago patient was playing in the backyard sandbox when she heard him suddenly start coughing. The coughing lasted only moments, but he has been audibly wheezing since. Mother was concerned, because his breathing has not returned to normal, so she brought him to the ED. On exam, the child is playful and well appearing. Wheezing is heard in the mid-right chest area. O2 sats are 100% on room air.

Clinical trial eligibility criteria: eligible ages (years): 6.0-12.0,  Rhinitis, Allergic, Seasonal Asthma Children must be >= 6 to < 12 years of age of either sex and any race Children's parent(s) or legal representative(s) must demonstrate their willingness to participate in the study and comply with its procedures by signing an informed consent Children must be free of any clinically significant disease (other than SAR) that would interfere with study evaluations Children's parent(s) or legal representative(s) must understand and be able to adhere to dosing and visit schedules, agree to report concomitant medications and adverse events to the Investigator or designee The diagnosis of seasonal allergic rhinitis with or without intermittent asthma will be assessed by Clinical history of sneezing, rhinorrhea (nasal discharge/running nose or post-nasal drip), nasal stuffiness/congestion and nasal itching and non-nasal symptoms (eye symptoms) as itching, burning, tearing and redness, during the previous pollen season Ascertained skin prick positivity (or RAST positivity) to one of the following: grasses, parietaria, birch, hazelnut (the skin test has to be performed within the last year) Children must be clinically symptomatic with SAR at Visit 1 (day 1): the total (nasal + non nasal) symptoms score must be >= 8 with a nasal congestion score of >= 2, and the non-nasal symptoms severity score must be >= 2 Asthma symptoms (wheezing, cough, difficulty breathing, chest tightness) will be evaluated at visit 1 (day 1) and graded only for child with concomitant asthma  Children who have not observed the designated washout periods for any of the prohibited medications Children with persistent asthma (mild, moderate or severe) or perennial allergic rhinitis (PAR) Children with rhinitis medicamentosa Children who have had an upper respiratory tract or sinus infection that required antibiotic therapy within 14 days prior to Visit 1 (day 1), or children who have had a viral upper respiratory infection within 7 days prior to Visit 1 (day 1) Children who have nasal structural abnormalities, including nasal polyps and marked septal deviation, that significantly interfere with nasal airflow Children who, in the opinion of the Investigator, are dependent upon nasal, oral or ocular decongestants, nasal topical antihistamines, or nasal steroids Children with a history of hypersensitivity to desloratadine or any of its excipients Children who have any current clinically significant metabolic, cardiovascular, hepatic, renal, immunologic, neurologic, hematologic, gastrointestinal, cerebrovascular or respiratory disease, or any other disorder which, in the judgment of the Investigator, may interfere with the study evaluations or affect subject safety A known lack of response to H1-antihistamines