caused by exposure to pollens or other allergens.

seasonal rhinitis is usually allergic; at least 25% of perennial rhinitis is nonallergic.

pollens (oak, elm, maple, alder, birch, juniper, olive)
Summer: Grass pollens (Bermuda, timothy, sweet vernal, orchard, Johnson) and weed pollens (Russian thistle, English plantain)
Fall: Other weed pollens (ragweed), mold spores

sneezing, rhinorrhea, and nasal and sinus obstruction.
sinus obstruction and frontal headaches; sinusitis is a frequent complication.
Coughing / wheezing, especially if asthma is also present
Perennial: chronic nasal obstruction, sometimes in children leading to chronic otitis media; symptoms vary in severity throughout the year; itching is less prominent than in seasonal rhinitis.
Signs include edematous, bluish-red nasal turbinates, and, in some cases of seasonal allergic rhinitis, conjunctival injection and eyelid edema

- to identify a reaction to pollens (seasonal) or to dust mite, cockroach, animal dander, mold, or other antigens (perennial) for immune treatment
Eosinophilia in nasal smear + negative skin tests - suggests aspirin sensitivity or nonallergic rhinitis with eosinophilia (NARES).
Diagnosis of nonallergic perennial rhinitis: also based on history. Lack of a clinical response to treatment for assumed allergic rhinitis and negative results on skin tests and/or an allergen-specific serum IgE test also suggest a nonallergic cause; disorders to consider include nasal tumors, enlarged adenoids, hypertrophic nasal turbinates, granulomatosis with polyangiitis (Wegener) and sarcoidosis.