Allergic Rhinitis

Allergic rhinitis is also referred to as hayfever, nasal allergy or pollinosis. This is an inflammatory disease involving the nasal passages, sinuses, throat and eyes, provoking symptoms similar to a cold (e.g. sneezing, runny nose, blocked, nasal itching). Approximately 90% of patients with rhinitis also experience ocular symptoms (tearing, itchy eyes, redness, swelling). In that case, the disease is called allergic rhinoconjunctivitis.

Seasonal reaction is triggered by the pollen of specific seasonal plants. It is commonly known as “hayfever” because it is most prevalent during haying season. However, some allergic individuals suffer from hayfever throughout the year. Hayfever symptoms are likely to be worse when the number of grains of pollen in the air is high. Pollen causing nasal allergy varies from region to region and between individuals. In general, airborne pollen is the predominant cause. This is because they are very light and can remain in the air for long periods of time. The pollen of insect-pollinated plants is too large to be carried in the air and represents no risk.

The symptoms of coryza are considered severe when they result in impairment of daily activities, impairment of school or work, sleep disturbance. They are mild when these areas are not affected.

If symptoms of coryza occur at certain times of the year (pollen seasons) the disease is called seasonal allergic rhinitis (hayfever). If symptoms occur throughout the year the disease is called perennial allergic rhinitis.

Episodic symptoms of pollinosis can occur with sudden exposure to an allergen such as a cat or dog or horse. About 40% of patients with rhinitis experience symptoms of allergic asthma during the period of allergic symptoms.

Common symptoms of allergic rhinitis are:

  • Blocked nose or stuffy nose
  • Runny nose
  • Sneezing
  • Itching, itchy eyes, throat, lips, ears
  • Dark circles under eyes
  • Continuous throat clearing
  • Cough
  • Poor sleep or fatigue
  • Snoring
  • Reduced concentration ability
  • Impaired quality of life

 

If a patient has asthma, their symptoms may get worse when they have a stuffy nose. Patients may be present with Coughing, Shortness of breath, Chest tightening, Wheezing.

  • It is estimated that hayfever affects about 30% of the UK population. Its prevalence has increased in developed countries over the past 30 years, but the causes are not clearly understood.
  • Heredity and environmental factors may contribute to a predisposition to allergies.
  • A child has about a 30% chance of developing allergic rhinitis if one parent is affected. The risk increases to 50% if both parents have a history of allergies.

Examples of plants usually associated with hayfever include:

  • Grasses: In Britain grass pollen is produced from May to August and the main causes are ryegrass (Lolium sp.) and timothy (Phleum pratense). They affect 90% of sufferers of hayfever.
  • Trees: In the UK, tree pollen affects 25% of hayfever sufferers. Common pollen comes from birch (Betula), pine, alder (Alnus), cedar, hazel, hornbeam (Carpinus), horse chestnut (Aesculus). Olive pollen is most predominant in Mediterranean regions.
  • Weeds: Mugwort (Artemisia), plantain (Plantago), nettle/parietaria (Urticaceae), Fat hen (Chenopodium) and sorrel/dock (Rumex). Parietaria is most predominant in Mediterranean regions.

Perennial allergic rhinitis is generally triggered by house dust mites, molds, animals (cat, dog, mouse, rabbit, horse, etc), but pets can cause episodic symptoms with discrete exposures.