Final answer:
Corticosteroid inhalers are the recommended first-line management for a patient with seasonal rhinitis and a history of mild asthma, as they control long-term asthma and reduce inflammation associated with rhinitis.
Step-by-step explanation:
The best first-line management for a patient with recurrent seasonal rhinitis and a history of mild asthma would be Corticosteroid inhalers. These are recommended for long-term control of asthma and can reduce inflammation, which in turn helps with managing rhinitis symptoms. Immunotherapy might be considered for long-term treatment of allergies, but it is not typically the first line of therapy.
Similarly, Decongestants may temporarily relieve nasal congestion but do not address the underlying inflammation. Singulair (a leukotriene receptor antagonist) is also a viable option for preventing asthma attacks and managing allergic rhinitis. However, for first-line management, especially for those with a concurrent diagnosis of asthma, corticosteroid inhalers are usually the preferred treatment.