Clinical Features


There is no age or sex predilection. It may start in infants as young as 6 months or older people. Usually the onset is at 12-16 years of age.
The cardinal symptoms of seasonal nasal allergy include paroxysmal sneezing. 10-20 sneezes at a time, nasal obstruction, watery nasal discharge and itching in the nose. Itching may also involve eyes, palate or pharynx. Some may get bronchospasm. The duration and severity of symptoms may vary with the season.

Symptoms of perennial allergy are not so severe as that of the seasonal type. They include frequent colds, persistently stuffy nose, loss of sense of smell due to mucosal oedema, postnasal drip, chronic


cough and hearing impairment due to eustachian tube blockage or fluid in the middle ear.
Signs of allergy may be seen in the nose, eyes, ears, pharynx or larynx.
Nasal signs include transverse nasal crease a black line across the middle of dosrum of nose due to constant upward rubbing of nose simulating a salute (allergic salute), pale and oedematous nasal mucosa which may appear bluish. Turbinates are swollen. Thin, watery or mucoid discharge is usually present.

Ocular signs include oedema of lids, congestion and cobble­stone appearance of the conjunctiva dark circles under the eyes (allergic shiners).
Otologic signs include retracted tympanic membrane or serious otitis media as a result of eustachian tube blockage.

Pharyngeal signs include granular pharyngitis due to hyperplasia of submucosal lymphoid tissue. A child with perennial allergic rhinitis may show all the features of prolonged mouth breathing as seen in adenoid hyperplasia.
Laryngeal signs include hoarseness of voice and oedema of the vocal cords.

Diagnosis


A detailed history and physical examination is helpful, and also gives clues to the possible allergen. Other causes of nasal stuffiness should be excluded.

Investigations

1. Total and differential count. Peripheral eosinophiliamay be seen but is an inconsistent finding.

2. Nasal smear shows large number of eosinophils inallergic rhinitis. Nasal smear should be taken at thetime of clinically active disease or after nasal challengetest. Nasal eosinophilia is also seen in certain nonallergic rhinitis, e.g. NARES (nonallergic rhinitis with eosinophilia syndrome).

3. Skin tests help to identify specific allergen. They areprick, scratch a intradermal tests.

4. Radioallergosorbent test (RASTj is an invitro test andmeasures specific IgE antibody concentration in the
patient's serum.

5. Nasal provocation test. A crude method is to challengethe nasal mucosa with a small amount of allergen placedat the end of a toothpick and asking the patient to sniffinto each nostril and to observe if allergic symptomsare reproduced. More sophisticated techniques areavailable now.


Complications


Nasal allergy may cause:


1. Recurrent sinusitis because of obstruction to the sinusostia.


2. Nasal polypi.


3. Serous otitis media.


4. Orthodontic problems and other ill effects of prolongedmouth breathing especially in children.


5. Bronchial asthma. Patients of nasal allergy have fourtimes more risk of developing bronchial asthma.


Treatment