Humidifiers: to use them or not

DEAR DR.PAUL: A friend recently told me that having a vaporizer on all night while my two-year-old is sick is not a good idea. How do you feel about this and also about menthol used in the vaporizer? Thanks.

PEDIATRICIAN DR.PAUL Answers: I often get questions about vaporizers. In fact, it’s one of the most common questions from parents.The answer, I’m afraid, is not very clear cut, but let me try to explain. We need to have a certain level of humidity in the air we breathe in through our nose. The “normal” or “ideal” indoor humidity level is about 40-45%. Humidity levels over 45% can indeed be harmful, both directly and indirectly.

In asthmatic children, for example, high humidity may make the asthma symptoms worse. Indirectly, high humidity affects our health adversely by promoting mould growth and dust mites. Dust mites are microscopic insects that live in dust found in upholstered furniture and they thrive on high humidity. Dust mites are considered to be very important irritants in asthma and in chronic nasal allergies.

Moulds grow in the presence of high humidity and have been associated with causing or worsening asthma and other respiratory symptoms as well as other health problems.

How can you determine what the level of humidity is in your house? Special “hygrometers”, that look like thermometers, are readily available at any hardware or department store. These instruments can help parents monitor the humidity level at home.

Under normal conditions, and if the humidity levels are normal, a humidifier is not necessary. On the other hand, in the presence of high humidity (over 45%), and especially if a child has chronic asthma and/or respiratory allergies, the humidity needs to be decreased by using a dehumidifier. Low humidity is not good either as it dries up our respiratory tract, including the nose. In the case of low humidity, a central humidifier may help to bring up the humidity and maintain it at normal levels.

Still following me? Well, the issue can get even more complicated. We know that one of the treatments of a cold is humidity because it helps the congested child breathe easier. So, in this case, extra humidification for a short time may help, even if the normal humidity level in the room is normal. However, in asthmatic children, I do not generally recommend extra humidification even during a cold. Although humidifiers may help a child with a cold, they should not routinely be used in asthmatic children, unless discussed with your doctor.

Presuming that one uses a humidifier, there are several issues: One is cold mist versus warm? I prefer cold, as it is safer. Warm mists may accidentally spill and scald a child. Next, vaporizer versus humidifier? In general, I do not think there is much difference between the two.

What about adding menthol (lotion or rub) to vaporizers? I do not recommend this as some studies have suggested that the associated fumes may be potentially toxic. On a final note, a potential problem relates to not cleaning the filters frequently or adequately. Moisture left in the humidifier (or vaporizer) can harbour mould and bacteria. An improperly maintained or unclean humidifier may be actually spreading germs and harming a child.

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Pediatrician DR.PAUL Roumeliotis is certified by the American Board of Pediatrics and Royal College of Physicians and Surgeons of Canada. The information provided above is designed to be an educational aid only. It is not intended to replace the advice and care of your child’s physician, nor is it intended to be used for medical diagnosis or treatment. If you suspect that your child has a medical condition always consult a physician.