Allergens behind phlegm build-up

Q. I am a 46-year-old woman with a healthy BMI. I jog for about half an hour two or three times a week.

For years, my body, especially my hands, are icy cold during my jogs.

After jogging (either in the gym or outdoors), I frequently have red, itchy patches on the front and back of my body, except my limbs. This is despite my wearing sports attire made of quick-dry material.

A few months ago, I started swimming frequently. While swimming, I tend to have lots of phlegm, although I am well. I have to stop every few laps to clear my nose and throat. I did not have such a problem previously.

Are these problems normal?

A. Your problem of having phlegm while swimming could be due to phlegm building up within the sinus cavity over the past few days or weeks.

This is possibly due to a previous allergic reaction or sinus infection.

The phlegm gets expelled or forced out during the swim as the activity accentuates the airflow and breathing in the nose and sinuses.

This is actually good for the body, and you should blow out all the mucus and phlegm.

In general, our nose and throat contain mucus-producing glands.

These glands are important in lubricating and moisturising the nasal and oral passages.

They also ensure that the mucosa (skin) of the mouth and nose do not stick together when the environment gets too dry.

The moisture on the oral surface, the palatal surface (roof) of the mouth and the tongue also helps in taste sensation.

Mucus is produced in reaction to allergens during an allergic reaction.

When there is excessive production (allergic rhinitis) of mucus in the sinus or nose, it tends to cause nasal obstruction, runny nose or post-nasal drip (when the mucus runs down the throat).

Try to identify any potential allergens in your environment, either at the workplace or at home, which may cause the build-up of phlegm in your sinus cavity.

Another less common reason for your problem is an allergy to chlorine, a chemical found in most swimming pools. However, this usually manifests as skin irritation, eye discomfort or breathing difficulties.

Consult a doctor if this problem persists and affects your swimming routine or regular exercise regimen.

Otherwise, you might want to consider taking an antihistamine before the swim.

There are also some nasal saline rinses which you could buy over the counter. These are used to flush the nasal cavity, which could be helpful for your situation.

On the other hand, having itchy skin after jogging is not uncommon.

Given that it is not triggered by irritation from soap or cosmetic products, the discomfort is most likely due to the chemical histamine, which is released during exercise.

Histamine is produced by the body's cells for a variety of functions, including regulating sweat.

During exercise, the blood vessels dilate and become more permeable to cells and other blood substances.

Histamine is released to increase blood flow to regions under strain.

As a result, the allergic cells (mast cells) also escape from the blood vessels and release their allergic chemicals, causing red itchy patches which mimic an allergic reaction.

DR KENNY PANG
Ear, nose and throat consultant at Asia Sleep Centre at Paragon Medical

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