Many other trees cause problems from late winter through June. Olive and privet are closely related and pollinate from May until August. Persons suffering from late-March until June or July are usually allergic to grass pollens while those with late summer and fall symptoms often have weed or mold allergy. Because coastal California has a long growing season, persons allergic to many types of pollen may suffer symptoms from early winter until late autumn. In perennial rhinitis, symptoms are present year-round and are usually due to things present in the home or occasionally in the diet.
Symptoms are typically worse at night and upon arising in the morning.
In addition to the usual complaints, perennial rhinitis may produce chronic symptoms that, at first, may not seem allergic. Sinus headache, loss of the senses of smell and taste, lack of energy from poor sleep, and malocclusion of the teeth are some examples. The most common cause of perennial allergy complaints is the dust mite which live primarily in bedclothes, carpeting, and upholstered furniture. Pets are another significant cause. The worst offenders are cats and dogs but small rodents, rabbits, and birds may also be troublesome.