Rhinitis is inflammation of the nasal mucosa (lining of the nose) and is characterized by a symptom complex that consists of any combination of the following:
- nose congestion,
- itching of the nose, and
- "runny" nose.
The eyes, ears, sinuses, and throat can also be involved. Rhinitis of the nose can be due to (a) the common cold or due to (b) nose allergies (also known as allergic rhinitis).
Allergic rhinitis is the most common cause of rhinitis. It is an extremely common condition in Singapore, and is estimated to affect over 30 to 40% of our population. Allergic rhinitis involves inflammation of the skin lining of the nose, eyes, ears, sinuses, and pharynx (mouth).
In terms of immunology, the inflammation of the nose skin lining is due to a complex interaction of inflammatory proteins triggered by an immunoglobulin E (IgE)–mediated response to an allergy protein (known as an allergen). The tendency to develop this allergic (IgE-mediated) reaction to allergens (proteins capable of causing an allergic reaction) has a genetic component. In susceptible individuals, exposure to certain foreign proteins (allergen) leads to allergic sensitization, which is characterized by the production of specific IgE directed against these proteins. When the specific protein (eg, a specific pollen grain, or dust mite) is inhaled into the nose, it will bind to the immunoglobulin (IgE) on the mast cells (allergic cells), leading to release of the allergic mediators. These mediators lead to the symptoms of "runny" nose, nose congestion, sneezing, nose itching, redness, tearing, swelling, ear pressure, and postnasal drip. There are 2 main phases:
- the immediate phase and
- the delayed phase.
Allergy of the nose can be associated with a number of co-morbid conditions, including
- topic dermatitis (eczema/skin allergy), and
- nose polyps (swelling in the nose).
According to the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines, the relationship between the development of allergic rhinitis (nose allergy) and the development of asthma has been shown to be related and are manifestations of 1 syndrome in 2 parts of the respiratory tract.
Allergic rhinitis (nose allergy) has been identified as a significant risk factor for the development of bronchial asthma, it is well accepted that allergic rhinitis may precede the onset of asthma symptoms and that asthma will not be optimally controlled unless the allergic rhinitis is also effectively managed.
Based on the ARIA guidelines, allergic rhinitis is divided into 2 main types:
- intermittent disease and
- persistent disease.
Patients with intermittent disease have symptoms for less than 4 days/week and less than 4 weeks/year, whereas patients with persistent disease have symptoms for more than 4 days/week for more than 4 weeks/year.
The complications of allergic rhinitis include
- otitis media (ear infection)
- eustachian tube dysfunction (blocked swollen eustachian tube),
- acute sinusitis,
- chronic sinusitis and
- significant impairment of quality of life (such as fatigue and drowsiness)
Symptoms and signs of allergic rhinitis include "runny" nose, nose congestion, sneezing, nose itching, redness, tearing, swelling, ear pressure, and postnasal drip. Most patients also have watery eyes and itchy eyes. Throat symptoms include persistent phlegm, recurrent sore throat and chronic cough. "Allergic shiners" are dark circles around the eyes and are related to vasodilation or nose congestion. "Nose crease" is a horizontal crease across the lower half of the bridge of the nose that is caused by repeated upward rubbing of the tip of the nose by the palm of the hand (ie, the "allergic salute"). The skin of the nose lining may be swollen (boggy) and with the swelling, the nasal passage is narrowed, resulting in difficulty breathing and nasal congestion.
Sleep and Nasal Allergy
Sleep problems are common in people with allergic rhinitis. Many studies have shown that sleep quality is impaired by nasal allergic symptoms and that the degree of impairment is related to the severity of those symptoms. In addition, sleep problems are linked with fatigue and daytime sleepiness as well as decreased productivity at work or school, impaired learning and memory, depressed mood, and a reduced quality of life. In addition, clinical researches suggest that allergic rhinitis (nose allergy) is a risk factor for snoring and obstructive sleep apnea among children. Snoring and other sleep problems are linked with poor performance in school, lower IQ, and short attention span in school. Parents are urged to pay close attention to sleep symptoms in children with allergic rhinitis.
Allergy testing is used for testing reaction to specific allergens which can be helpful to confirm the diagnosis of allergic rhinitis and to determine specific allergic triggers. If specific allergic triggers are known, then appropriate avoidance measures can be recommended. The most commonly used methods of determining allergy to a particular substance are allergy skin testing and in vitro (blood test sent to the laboratory) diagnostic tests, such as the radioallergosorbent test (RAST).
Skin testing may be either
- skin prick testing – entails a scratch or a prick on the surface of the skin, in order to observe the immediate phase reaction, which is the wheal (swelling) and/or the erythema (redness); or
- intradermal testing – involves injecting the allergen into the skin dermal layer, this test allows the activation of the mast cells (inflammatory cells of allergy). The intradermal testing is more sensitive than the skin prick testing, and hence, will require a specialist doctor near by.
Blood testing for IgE specific allergen can be done in the laboratory. These are known as radioallergosorbent testing (RAST), these tests allow determination of specific IgE to a number of different allergens from one blood sample. Total serum IgE is the measurement of the total level of IgE in the blood (regardless of specificity). While patients with allergic rhinitis are more likely to have an elevated total IgE level than the normal population, this test is neither sensitive nor specific for allergic rhinitis.
Blood tests also include testing for IgG antibody levels to specific allergens (there are many arguments/controversies for and against the theory of IgG subclass antibodies being involved in allergy). Of late, a number of clinical laboratories have set up ELISA/EIA (Enzyme Immunoassays) panels to test the presence of IgG antibodies in patients with food allergies. This is based on the findings that certain subclasses of IgG have been associated with the in vitro degranulation of basophils and mast cells, the activation of the complement cascade, (both of which are important mechanisms in allergy and anaphylaxis) and the observation that high circulating serum concentrations of some IgG subtypes have been measured in certain allergic individuals. The premise behind this testing is that high levels of IgG antibodies are occasionally correlated with clinical food allergy signs and symptoms. With these tests, the physician may advise the patient to avoid these foods.
Management of nasal allergies, according to the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines, consists of 4 major categories of treatment:
- environmental control measures and allergen avoidance,
- pharmacological management,
- surgery and
(1) Use of environmental controls is not adequately explored in most patients. For most patients, the removal of the trigger can have a dramatic effect. The difficulty arises when the trigger needs to be identified and eliminated. Eliminating the trigger may be simple if removal of a feather pillow or blanket is involved; however, it can be very difficult if a family pet needs to be removed. To reduce dust mites, special allergen-proof covers for pillows and mattresses may be obtained. The important factor is that the covers must be plastic on one side and have a zippered closure. The pillow must be covered, which is more crucial than covering the bed mattress itself because the pillow is where the patient's head usually spends most of the night. For animal allergy, complete avoidance is the best option. For patients who cannot, or who do not want to, completely avoid an animal or pet, confinement of the animal to a non-carpeted room and keeping it entirely out of the bedroom can be of some benefit. Cat allergen levels in the home can be reduced with high-efficiency particulate air (HEPA) filters. There are facilities to clean up and remove the dust mite in your environment.
(2) Most cases of allergic rhinitis respond to medication. Patients may be treated with oral antihistamines, decongestants, or both as needed. Regular use of an intranasal steroid spray may be more appropriate for patients with chronic persistent symptoms (see ARIA guidelines above).
Daily use of an antihistamine, decongestant, or both can be considered either instead of or in addition to nasal steroids.
(3) Surgery for allergic rhinitis is mainly indicated for patients who have tried medication and who are either unwilling to continue medication or have no effect with medication. This involves mainly reduction of the size of the sinus turbinates and/or correction of the nasal septal deviation. Various techniques are available, from radiofrequency to the turbinates, laser treatment and turbinectomies. These procedures are useful and should used together with allergen avoidance. Surgery is also indicated for complicating conditions, such as chronic sinusitis, severe nasal septal deviation (causing severe obstruction), nasal polyps, or other anatomical abnormalities.
(4) Immunotherapy (desensitization) is the use of gradual exposure of low dose allergens to the patient (either through skin injections or sublingual/drops given beneath the tongue). However, this is a long-term process; noticeable improvement is often not observed for 6-12 months, and, if helpful, therapy should be continued for 2 to 3 years. Immunotherapy is not without risk because severe systemic allergic reactions can sometimes occur. For these reasons, carefully consider the risks and benefits of immunotherapy in each patient and weigh the risks and benefits of immunotherapy against the risks and benefits of the other management options.