The introduction of nasal corticosteroids 20 years ago has been the mo
st important therapeutic progress in rhinitis management since the int
roduction of the first generation of antihistamines. Our knowledge of
the mode of action of corticosteroids is still incomplete, although a
series of intranasal studies has now clarified this problem as the air
way mucous membrane of the nose is easily accessible for investigation
. Nasal corticosteroids are a highly effective therapeutic modality th
at can be used for long term therapy of allergic rhinitis, perennial n
onallergic rhinitis and nasal polyposis. Experience for 20 years has s
hown that the adverse effects from this type of treatment are negligib
le, and far less serious than those occurring in the skin following lo
ng term use of corticosteroid ointment. Intranasal corticosteroids can
therefore be considered as first-line treatment for allergic and nona
llergic rhinitis. The major disadvantage of this type of treatment is
the slow onset of action and the lack of effect on itchy eyes. For tha
t reason, the second generation antihistamines are the drugs of choice
in patients having occasional symptoms. However, in our opinion, intr
anasal corticosteroids are preferable in patients who have symptoms on
a regular basis, either in the pollen season or all year.