What Is Acne mechanica?

Acne mechanica is common among people who play sports and young soldiers in hot climates.

If acne lesions start to sprout in places where your skin gets rubbed — such as on your shoulders where you carry your backpack, across your forehead beneath your hat or helmet, on your chin just under your helmet chin strap, or where you hold your cell phone — acne mechanica may be to blame.

The Basics of Acne Mechanica

Acne mechanica is a type of acne or pimples that’s caused by skin friction, heat, pressure on the skin, or when skin isn't exposed to the air. Sweaty, constantly rubbed skin can quickly break out in a bothersome rash that's really acne. The most common causes of acne mechanica include wearing:

A helmet with a chin strap

A tightly fitting hat for a long time

Any equipment or gear that requires using straps, such as a backpack

A musical instrument pushed against the skin for long periods (like a violin)

Shoulder pads

Tight, synthetic headbands

Tightly fitting clothing or bras

Who Gets Acne Mechanica?

Certain factors increase the risk of developing acne mechanica, making some people more likely to get it. Acne mechanica is most likely to affect:

Teenagers and adults in their twenties, who already have a problem with acne on their buttocks, shoulders, and back

People with sandpaper acne, which are small, rough acne lesions that are difficult to see but feel like sandpaper

Soldiers, especially young ones, who are stationed in hot, humid, tropical areas: They get acne mechanica because of the heavy equipment and weapons that they carry.

Treatment and Prevention for Acne Mechanica

Acne mechanica responds well to simple topical treatments that contain the ingredients benzoyl peroxide or salicylic acid. These acne treatments, which can effectively clear up acne mechanica, come in creams, lotions, gels, cleansers, and other solutions.

Because this type of acne has clear causes, you can try to prevent acne mechanica by:

Taking a shower promptly after exercising or sweating — making sure that your skin is thoroughly cleansed.

Using a cleanser that includes the ingredient salicylic acid to help clear the skin of sweat and grime.

Not wearing a hat, helmet, or headband for long periods of time.

Putting on a T-shirt — make sure it's made of absorbent cotton and is clean — beneath a uniform to help soak up sweat and minimize skin friction.

Not wearing too-tight clothes

It isn't always possible or safe to avoid acne mechanica triggers — you shouldn’t put yourself at risk of injury by not wearing a helmet, shoulder pads, or other protective gear when you play sports or perform certain kinds of work.

But now you know what's probably causing those pimples on your shoulders or under your clothes, and you can take steps to prevent acne mechanica by protecting your skin and keeping it clean, and treating the condition to prevent pimples on your skin.