Allergic Rhinitis

Rhinitis occurs when there is inflammation of the inner lining of the nose. Allergic Rhinitis is a condition where there is hypersensitivity by the immune system to allergens. Allergic rhinitis is triggered when the body responds to allergens by producing antibodies. Histamines are released into the bloodstream leading to allergic symptoms. Allergic rhinitis is a common upper respiratory infection that affects nearly a fifth of the population. Allergic rhinitis is often associated with severe asthma, otitis media and sinusitis. This manifests in symptoms such as sneezing, nasal congestion, stuffy nose and itchy eyes. Some persons suffering from allergic rhinitis may experience frequent headaches and difficulty in hearing and smelling. This condition can bring on fatigue, sleep disorders and drowsiness.

Seasonal allergic rhinitis is also known as hay fever and is noticed during autumn. On the other hand perennial allergic rhinitis is a condition where the patient suffers rhinitis symptoms due to exposure to pet hair, carpeting, upholstery or air pollution. Patients suffering from perennial allergenic rhinitis tend to notice the symptoms irrespective of the season. Some of the common allergens are pollen, mold, animal dander, feathers, dust and grass. The symptoms are usually noticed more in winter. Certain foods and spices might increase nasal secretions associated with allergenic rhinitis. Stress and gastroesophageal reflux can trigger the symptoms of allergic rhinitis. There is post nasal drip and cough and may be accompanied by loss of smell.

Antihistamines are prescribed to block the action of the histamines created by allergy. But antihistamines tend to cause drowsiness. Decongestants can help in alleviating the symptoms of allergic rhinitis such as stuffy nose. Decongestants must be used with care on those suffering from , thyroid problems and heart conditions. Corticosteroids are useful in treating allergic rhinitis since they reduce the reaction by the body to the histamines. Steroid nasal sprays can help reduce nasal inflammation and allergy. Mucus thinning agents are prescribed for patients suffering from allergic rhinitis to make the nasal secretions less sticky so that they do not coagulate at the back of the nose and throat.

• Keep away from pets if you are extremely allergic to animal dander
  
• Use pillows made from hypoallergenic material such as dacron or polyester
  
• Use HEPA filter for your bedroom and living area
  
• Resort to vacuuming instead of dusting
  
• Drink adequate fluids
  
• Sleep with the head at a slight elevation
  
• Balanced diet
  
• Avoid nasal irritants like perfume, cigarette smoke, car exhaust and aerosol sprays
  

Hay fever

Hay fever is an allergic reaction. Allergic Rhinitis, the medical term for hay fever means irritation of the nose. Hay fever usually starts during childhood or early adulthood and often diminishes slowly over decades. Hay fever is brought about by allergic reaction to outdoor or indoor contaminants, such as plant pollen, dust mites or chemicals. Anyone can develop hay fever especially those who are exposed to years of repeated inhalation of allergic substances. People who suffer from asthma and eczema are more prone to hay fever. It also tends to run in families. Passive smoking increases risk of developing hay fever.

Symptoms

Some people have symptoms all round the year. For others hay fever symptoms worsen at specific times of the year. Spring and fall are considered as main hay fever seasons. In severe cases nose bleeding may occur. Otherwise, the common symptoms of hay fever are:

• Repeated sneezing
  
• Runny or itchy nose
  
• Itchy or watery eyes
  
• Itchy, irritation in the throat, palate and ears
  
• Inability to concentrate
  
• Loss of sense of taste and smell
  
• General feeling of being unwell
  
• Feeling exhausted
  

Diagnosis

Skin prick test: After determining possible allergy-causing substances, a small amount of suspected allergy-causing substance is placed on the skin. Depending on patient's preference it could be on the forearm, upper arm or the back. The skin is pricked so the allergen goes under the skin's surface. The health care provider observes the skin for possible reactions like swelling, itchy feeling and redness of the skin. Reactions, if any can be noticed within 15-20 minutes which confirms hay fever. Skin prick test is not recommended for people with eczema or those taking certain medications like antihistamines as it will interfere in responding to allergic reaction. In such cases, blood test is done.

Blood test: Blood test is recommended when skin prick test cannot be done or if the results of skin prick test are not useful. A sample of blood will be taken from a vein in the arm and tested for the presence of the Immunoglobulin E (IgE) antibody. If the blood test is positive, it confirms the presence of hay fever.

Treating hay fever

The aim of treatment would be to stop exposing the body to allergic substances or preferably avoid it completely. There are a plethora of options to treat hay fever. The choice of treatment depends on the severity of hay fever and the symptoms. Age, occupation and life style is also given due consideration.

• Antihistamines medicines
  
• Antiallergic nasal sprays or eye drops
  
• Antihistamines sprays or drops for nose or eyes
  
• Steroid sprays or drops for the nose only
  
• Decongestant sprays
  
• Decongestant tablets
  
• Steroid tablets or injections
  
• Desensitizing injections
  

Some medications do not require prescription and are sold over-the-counter as non-prescription medications. It is best to seek health care provider's opinion taking into account the possible side effects.

• Know triggers and keep away from allergens
  
• keep environment clean
  
• Eat a healthy oil-free diet
  
• Include a lot of vitamin C
  
• Increase protein intake
  
• Drink boiled, filtered water
  
• Don't miss to drink herbal tea
  
• Avoid venturing out when pollen count is high
  
• Don't skip medications
  

Antihistamines

Allergies are one of the most common types of acquired health conditions as the causes include various factors. Most of these factors are related to the environment such as dust, pollen, virus and chemicals. Allergic reaction signifies the defense mechanism of the immune system to a foreign particle. Allergic reactions if untreated can lead to bigger complications such as bronchitis and sinusitis. Antihistamines were first synthesized by Daniel Bovet. They play a major role in controlling the release of histamines in the body which are produced as response to an allergen. Histamines are chemicals which are released from the mast cell damage. These chemicals initiate the process of allergic reaction in the blood and tissues which causes discomfort. Histamines have three types of receptors H1, H2 and H3 which are specific for different organ systems. The H1 receptor is associated with vasodilation and smooth muscle stimulation, H2 receptor is associated with the cardiac stimulation and H3 is associated with the feedback inhibition process regulated by the central nervous system.

Types of antihistamines

Antihistamines mainly act upon the receptors of the type of histamine released. Each antihistamine has a tendency to compete in binding to the receptors to inhibit the process of allergic stimulation caused in the organ system. There are two major classes of antihistamines. The first generation and the second generation are classified based on their sedative effect on the patient during the course of their action. The first generation of antihistamines are sedatives as they act upon the parasympathetic nervous system in preventing the release of acetylcholine. Their anticholinergic properties enable them to act fast in providing relief within a few minutes. People who experience motion sickness are often suggested to take antihistamines because it suppresses the ear balance discomfort.

The most common ingredients present in these medications are chlorpheneramine, doxylamine, brompheneramine and dimenhydrinate. Most of these first generation antihistamines are recommended in allergic reactions such as hay fever, viral infection, pollen and dander as they suppress the central nervous system. Patients experience drowsiness for a period of time during the first generation antihistamine treatment.

Second generation antihistamines are not sedative in nature and they have large molecular size and electrostatic nature which makes them noncompeting to cross the blood and brain barrier. The response pertaining to their action is comparatively slow as they do not act upon the central nervous system. Studies have shown the increased administration of non-sedative antihistamines in the recent times. Some of these second generation antihistamines have been banned from the market due to their adverse side effects such as arrhythmia. Most of these antihistamines are prescribed during seasonal allergies.

Side effects of antihistamines

The common side effect of most first generation antihistamines is drowsiness or dizziness. The other side effects include nausea, feeling of dryness in mouth and nostrils and sometimes blurred vision. These happen because of the inhibition of secretions from salivary, nasal and lachrymal glands during the onset of an allergic response. The suppression of central nervous system activity may initiate confusion, disorientation and sometimes hallucination in patients.

Rashes, chest congestion and difficulty in breathing have also been reported as adverse effects of antihistamine administration. In case of H2 receptor antihistamines, diarrhea is significant side effect along with headache. Most of the side effects caused by antihistamine intake subside within a few hours. However increased sensitivity to a certain type of antihistamine has to be immediately reported to the physician.