ALLERGIC RHINITIS OR HAY FEVER
It is a type of inflammation of the nasal mucous membrane due to the over-reaction of the immune system to any kind of allergens present in the environment.
When working well, our immune system protects us from the bacteria, viruses and toxins that enter our bodies. With hay fever though, something goes horribly amiss and it starts to over-react to harmless substances such as pollens, grasses, and animal dander. This allergic response results in a cluster of symptom that make life miserable.
Exposure to allergens generates allergen-specific IgE after T-cell release of interleukins 4 and 13, and B-cells producing IgE antibody which produces sensitization which leads to cross link of atleast two IgE antibodies bound to the high-affinity IgE receptor on presensitized effector cells, that is, mast cells or basophils8.
Phases of allergic response-
§ Early phase-
Duration- 20 minutes to an hour.
Symptoms includes- sneezing, pruritus and clear rhinorrhea.
Mediator- Histamine appears to be a major mediator.
§ Late phase-
Duration- begins in 3 to 6 hours, peaks at 6 to 8 hours and subsides in 12 to 24 hours.
Symptoms- sneezing, nasal obstruction, lacrimation, etc.
Mediator- chemokines and cytokines play a major role. Eosinophil activates release of leukotrienes which develops nasal congestion.
1. Seasonal – It occurs only in a particular season or only for a limited period of the year. It is also called as intermittent allergic rhinitis. It is caused by sensitivity to airborne mold spores or to pollens from trees, grasses or weeds.
2. Perennial– It remains throughout the whole year. It is also called as persistent allergic rhinitis. It is generally caused by sensitivity to dust mites, pet dander, mold or cockroaches.
§ Clear rhinorrhea9
§ Stuffiness of the nose
§ Itching in the nose and the eyes
§ Heaviness in the head or headache
§ Hyposmia/ anosmia10
§ Some skin complains like urticaria also can be present.
§ Facial pain and fullness10
§ Feeling of chest tightness
§ Genetic factors.
§ Environmental factors.
§ Production of IgE.
§ Temperature changes
§ Cold climate
§ Air pollution
On physical examination, it may show following:
§ Conjunctival swelling
§ Nasal polyps or enlarged nasal turbinates
§ Swelling of the eyelids
§ Middle ear effusion
A detailed history taking along with the following investigations may help to confirm the diagnosis:
1. Skin-prick testing13–
A small volume of a set of known allergens is injected into the dermis and any “weal and flare” reaction is taken as a positive response to that allergen.
1. Blood test13–
RAST (Radio-allergo-sorbent test) detects specific circulating IgE antibodies.
1. Nasal smear-
It may reveal large number of eosinophils and presence of neutrophils14.
§ Viral rhinitis
§ Bacterial rhinitis
§ Vasomotor rhinitis
§ Hormonal rhinitis
§ Rhinitis medicamentosa
§ Atrophic rhinitis
§ Gustatory rhinitis
§ Avoid exposure to dust or exposure to any allergen as much as possible.
§ Wearing mask may prevent entering of the allergens.
§ Use of glasses or sunglasses.
§ Grass pollen
§ Dust mites
§ Animal saliva