My Daughter’s Armpits Smell Like Onions: What to Do?

Body Odor: Common in Girls and Boys

Firstly, know that hundreds of people like you search for information every day about sweating and body odor in young girls and boys.

Here are some of the keywords often searched on Google related to this topic:

As you can see, some parents worry about their daughter’s (and their son’s) body odor as early as age 6. There are even people wondering if it’s normal for their 4 yeat old to have smelly armpits.

Even younger: infants often sweat a lot when they sleep, and this body odor as early as a few months old can be concerning!

However, it’s a natural phenomenon: babies and young children have more difficulty regulating their body temperature than adults. Hence, they sometimes sweat more in an attempt to regulate it better.

But why does this happen more in some children? That’s what we’re going to explore.

Why Do Some Children Sweat More Than Others?

Sweating is one of the many physical characteristics that vary among individuals, including children. Often due to genetic reasons.

When sweating becomes excessive and troublesome in children (as in adults), it’s called hyperhidrosis.

There are two forms of hyperhidrosis:

• Primary hyperhidrosis: the most common, occurring in 90% of cases. It’s considered idiopathic: without identifiable cause, probably of genetic origin;
• Secondary hyperhidrosis: in 10% of cases. It’s linked to a disease, medication intake, or a particular condition. See diseases causing excessive sweating. Both primary and secondary hyperhidrosis can begin in infants or very young children. Although most often, it starts at puberty.

If your child sweats more than average, they are likely affected by primary hyperhidrosis. You can discuss this with your general practitioner (there aren’t really doctors specialized in sweating) to rule out a specific cause.

Why Do Some Children Have Sweat That Smells Bad?

One can sweat excessively without necessarily smelling bad.

Sweat itself is odorless.

It’s only when sweat comes into contact with bacteria present on the skin that it can produce unpleasant odors.

Again, not all children or adults are the same. Some naturally have more bacteria on their skin surface, leading their sweat to smell worse.

The clothing and underwear worn as well as the sheets used for sleeping can also increase bad odors, especially if they are warm, damp, and not breathable.

See: anti-sweat sheets (coming soon in english)

Just like poor personal hygiene. From experience, however, I know that it is quite rare to be concerned about the bad odor of one’s sweat AND have poor personal hygiene!

4 Things to Do Against Sweating in Your Son or Daughter?

It’s important to distinguish between two things:

1. Sweating more than average, without necessarily having sweat that smells bad.
2. Having sweat that smells bad.

Because depending on what bothers us (the bad odor vs. the excess sweat regardless of odor), the treatments and tips to implement will not be the same.

1 – Ask yourself if it’s really a problem for him or her

Children have great adaptability. Even if excessive sweating can lead to some teasing from their peers, it’s not certain that they will suffer from it in the medium or long term. And even without that, like all children, they will be the target of new teasing.

Perhaps their sweating bothers them when practicing sports with some of their friends, like climbing or judo. But isn’t this an opportunity to discover other sports in which hyperhidrosis won’t be a hindrance at all, like soccer or athletics?

As a parent, you may feel that excessive sweating or bad odors must greatly bother your child. But when you look at it objectively, you may realize that it’s not really the case. Some people, even those with severe hyperhidrosis, did not suffer from their sweating during childhood.

Some parents who had hyperhidrosis as children also say, “I don’t want him/her to suffer like I did.” But it’s their retrospective adult perspective on the disease that makes them say that.

Perhaps if they had been asked as children, they were actually not happier or sadder than other children their age.

These are points to reflect on, and it’s up to you, of course, to make of them what you will!

2/ Consider Using Deodorant or Antiperspirant for Children

Is your child complaining that their sweat smells bad or is bothersome?

In this case, using deodorants (to combat bad odors) or antiperspirants (to sweat less) is an option.

There are now studies testing the effectiveness of antiperspirants in children (Remington 2021).

They are not contraindicated, and there is no reason to think that, when used with caution, they are dangerous for children and adolescents.

Even though as a precaution, some websites like Etiaxil specify a minimum age of 15 years to use them.

It’s possible to test the effectiveness of an antiperspirant, for example, in a teenager suffering from excessive underarm sweating.

Antiperspirants are most commonly based on aluminum salts. There are specific ones for each part of the body: armpits, feet, hands. Here’s a selection:

• Carpe for underarm – See on Amazon
• Dove for underarm – See on Amazon
• SweatBlock for underarm – See on Amazon

Some people (this was my case) describe becoming accustomed to antiperspirants: after a certain time, they no longer have an effect, both in adults and children.

There are also simple deodorants that can mask odors. For example, alum stone (see on Amazon), or simply washing the armpits several times a day with Marseille soap.

Antiperspirants should be applied to dry skin, preferably in the evening.

3/ Find clothes that limit bad odors

Certain textile materials are less likely to cause bad odors. Also, the looser and more temperature-appropriate a garment is, the less likely it is to cause sweat odors.

Here are the materials to avoid in case of malodorous sweating in children:

❌ Flannel cotton: cotton woven in a way that retains more body heat
❌ Sponge (80% cotton and 20% polyester): less effective than pure cotton for anti-perspirant properties
❌ Silk: to be avoided, as it retains a lot of moisture.

And the materials to favor:

✅ Percale cotton: tightly woven cotton, also absorbent;
✅ Fleece: always made of cotton. Very absorbent. Shares some common properties with flannel;
✅ Fil d’Écosse; cotton satin: it is also made from cotton fiber. Smoother than normal cotton (which is not inherently useful against sweating);
✅ Linen;
✅ Cashmere: quite absorbent;
✅ Synthetic fibers: spandex, polyamide, polyester;
✅ Polypropylene;
✅ Acrylics.

4/ Learn about other treatments for sweating

In cases of very bothersome excessive sweating in your child, treatments are available. They all have potential side effects (like antiperspirants, which can cause itching or irritation), which need to be carefully weighed against the benefits and risks.

I discuss this further in this article: Everything about excessive sweating in children.

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Do you have any comments or questions? Your comments are welcome 🙂 !

You may also like:

• My blog on hyperhidrosis

 📚 SOURCES

Remington C, Ruth J, Hebert AA. Primary hyperhidrosis in children: A review of therapeutics. Pediatr Dermatol. 2021 May;38(3):561-567. doi: 10.1111/pde.14551. Epub 2021 Mar 4. PMID: 33660889.