Histamine is the main reason why nasal allergy occurs. It really causes the blood vessel in the mucous membranes heighten and spilling of the fluid. Heightening will cause congestion within the nasal passages and the spilling of fluid is responsible for having a runny nose. If the nasal allergy becomes severe already, the mucous membranes will is already instigative and itchy.
Scientist had decided to combine few types of antihistamines medicines to prevent the reaction of histamine with its receptors on cells so it can lessen the severances of the allergy problems. Just like when taking medications such as diphenhydramine, chlorpheniramine, cetirizine, clemastine, fexofenadine, loratadine, terfenadine, and astemizole. Drowsiness is usually caused when you take diphenhydramine, chlorpheniramine, cetirizine and clemastine while taking fexofenadine and loratadine causes less drowsiness. Terfenadine and astemizole will not cause any negative effect only they have interaction effect especially in antifungal and antibiotic treatment.
To reduce the instigative and itchy feeling of the nasal passages corticosteroids hormone is used. Nasal allergy is commonly accompanied by inflammation. In fact, the body itself can secrete this hormone from the adrenalin gland. This will control the reactivity of the immune system and in case the level of the hormone is high, it will cause the immune system inert to fight against bacteria and viruses. While when hormone is at low level, it may cause hypersensitive to the body.
Nasal allergy is caused when the hormone level is low, when this happen it needs to apply the hormone to the mucous membrane externally just like a nasal spray or can be taken orally to lessen or avoid the inflammation of the nasal mucous membranes. This will also convert the actions of many cells present in the immune system. Today this kind of hormone are mostly what medical experts recommend to used as common medication for those who are affected by severe nasal allergy. But, taking advantage of this hormone often causes some negative effects like unpleasant aftertaste or even nosebleed.