I am not sure of your age but a CXR is definitely recommended if you are having low grade fever
with productive sputum.
or rhinosinusitis is a distinct possibility and antihistamines and nasal steroids
takes a minimum of 6 weeks to work and therefore must be continued for 3 months before stopping them.
As you have had improvement, it is advisable to continue them but also get a specific IgE blood test
to elucidate your allergies.
House dust mite/animal dander allergy is likely when you have perennial (all yer round) rhinitis.