An allergy is the body fighting harmless dust.
An allergy is the body’s defence system over-reacting to something harmless: house dust, pollen, mould, pet hair or a food. In the nose it causes sneezing and a runny, blocked nose. In the chest it can cause wheeze. It is common, runs in families, and can be well controlled.
In plain words.
Nasal allergy (allergic rhinitis) is the most common kind: bouts of sneezing, a runny or blocked nose, and itchy, watery eyes. It can come in seasons with pollen, or all year round with house-dust mites, mould and pets. Unlike a cold, it brings no fever, and it keeps coming back.
The nose and chest are one airway. Many people with nasal allergy also have asthma, and treating the nose often helps the chest. A nose that stays blocked disturbs sleep, and can lead to snoring and sinus infections.
Treatment is simple: avoid the trigger where you can, rinse the nose with salt water, use a steroid nasal spray every day through the season, and take a non-drowsy antihistamine tablet when needed.
Why the nose over-reacts
Pollen and dust land on the lining of the nose every day. In most people, the body sees they are harmless and ignores them.
In an allergy, antibodies on mast cells catch the pollen. The cells burst open and release histamine. The lining swells and pours out fluid: sneezing, a runny and blocked nose, and itching.
Go to hospital now if
- Swelling of the lips, tongue or throat, trouble breathing or swallowing, or a hoarse voice: call 112. This is a severe allergic reaction.
- Feeling faint, or a sudden rash all over, after a food, a medicine or an insect sting: call 112.
- If you have been given an adrenaline pen, use it straight away, then call 112. Lie down with the legs raised, or sit up if breathing is hard. Do not stand or walk. Use a second pen after 5 minutes if there is no improvement.
- Wheeze or breathlessness that your reliever inhaler does not ease: go to hospital now.
Call 112 or go to the nearest emergency department. Ambulance: 108 (102 in some states).
See a doctor within a few days if
- Symptoms disturb your sleep, work or school
- You wheeze, cough at night, or get breathless
- Your nose is blocked on one side only, or bleeds
- Thick yellow-green mucus with pain in the face lasts more than 10 days
- You have used decongestant nose drops for more than 5 days
- You have reacted to a food or a medicine
Tests that help.
Not everyone needs every test. He decides which ones are worth doing for you.
| Test | What it tells |
|---|---|
| Blood count (eosinophils) | Often raised in allergy. A simple first test. |
| Specific IgE | A blood test for chosen triggers such as dust mite, pollen, mould or pets. A positive result shows sensitivity, not always allergy, so it is read alongside your story. |
| Skin prick test | Tiny drops of common triggers on the skin; a raised bump shows a reaction. Done at an allergy clinic, after stopping antihistamines for a few days. |
| Spirometry | If there is wheeze or cough, to look for asthma. |
Have it ready.
Tick them off as you gather them. The ticks stay on this phone only.
Online, or in person?
Do not use decongestant nose drops for more than 5 days: the nose blocks up worse when you stop. And avoid steroid injections for allergy. A daily nasal spray works well, with far fewer side effects.
A video call can
- Tell an allergy from repeated colds or a sinus infection
- Plan sprays and tablets, and show how to use a nasal spray well
- Look for asthma when the chest is involved
- Help you find and cut down your triggers
Needs a visit in person
- Skin prick testing, at an allergy clinic
- Examination of the nose by an ENT doctor
- Spirometry, at a lung-function laboratory
- Any sign in the red box: that is an emergency
Talk it through with Dr. Arya.
Bring your reports and medicines to a video consultation. He goes through them with you, in plain words, and says clearly if you need to be seen in person.
Book a video consultationDr. Prabhat Arya · MBBS, MD (Internal Medicine) · Delhi Medical Council Reg. No. DMC-83759