- Acne mechanica is a form of acne caused by a combination of friction, heat and weight against the skin.
- Perspiration can also exacerbate this condition by further irritating the affected area.
- Acne mechanica can be treated by minimizing contact between the affected skin and irritants, maintaining cleanliness and applying topical acne treatments.
Acne mechanica is one form of acne vulgaris, a common skin condition. In its mildest form, it presents as pimples; in more severe cases, inflamed papules and pustules develop. Often confused with heat rash, it develops when skin becomes irritated by repeated abrasion as a result of clothing or other materials rubbing against the skin.
This, together with heat and pressure—typically as a result of tight sports equipment—create an ideal environment for blocked pores and a resulting increase in acne-causing bacteria.
What Is Acne Mechanica?
The three main contributors to this condition—heat, abrasion and pressure—each play a role in blocking pores:
- Heat causes pores to dilate, creating an ideal environment for sebum, or oil, and debris to accumulate
- Repeated friction chafes and irritates the skin, leaving dead skin cells on the surface
- Pressure seals in accumulated warmth, dead skin and debris against the skin’s surface.
When pores become clogged with debris and sebum, this buildup causes a bacteria that is naturally present in pores, Cutibacterium acnes (formerly Propionibacterium acnes) to proliferate. This response results in inflammation and the development of acne in the form of comedones, pustules or papules.
Where does acne mechanica occur?
Acne mechanica can occur anywhere on the body where repeated friction takes place.
Some of the most common areas are the forehead and back, due to tight-fitting hats and backpacks. Athletes such as soccer players may develop this acne on their lower legs due to their shin guards; chefs due to wearing hats for long periods of time.
Acne mechanica vs. other types of acne
Acne mechanica is basically the same as acne vulgaris, the most common type of acne. Both types develop as a result of clogged pores. When mild, blemishes present as whiteheads and blackheads, and in severe forms, pustules and papules.
What differentiates the two types is their root cause. While acne mechanica is triggered by pressure, heat and abrasion, acne vulgaris is not. As well, certain medications, dietary factors and elevated stress levels can also contribute to the formation of acne vulgaris.
Another difference is that acne mechanica is contained within specific areas subject to continuous or frequent friction; acne vulgaris typically develops on the face, neck and back, where there are more oil-producing sebaceous glands.
Acne mechanica can also be confused with heat rash, since both conditions cause a cluster of localized red pimples in mild cases. Heat rash most often occurs in hot weather when perspiration is trapped against the skin; it usually appears on the back, neck or chest.
However, heat rashes—unlike acne mechanica—can cause an itchy or prickly sensation, and often occurs in skin folds.
Causes of Acne Mechanica
This form of acne is most often associated with athletes, particularly those who wear protective gear for prolonged periods of time, such as football or hockey players. However, other activities and situations can also act as triggers.
Guitarists and marching band drummers can sustain friction on their shoulders as a result of wearing shoulder straps to hold their instruments. Similarly, violinists can experience breakouts due to chafing from the violin held against their chin. Anyone wearing tight-fitting backpacks pressed against their skin are also at risk of developing this acne.
Common work-related activities include wearing safety equipment such as a hardhat on a construction site can also cause irritated skin.
Lastly, everyday clothing such as tight-fitting T-shirts, hats, sweatbands and pants can be the cause for acne mechanica.
Treatments for Acne Mechanica
Acne mechanica is treated in the same way as inflammatory acne. Effective ingredients serve to unclog pores, reduce inflammation and kill acne-causing bacteria. Many of these can be found in over-the-counter (OTC) topical products.
Salicylic acid (SA) penetrates deep within pores to break up dead skin and clear pores, to treat and prevent future buildups. As a beta hydroxy acid (BHA), this acid speeds up cell turnover to exfoliate skin.
One of the most effective ways to use SA is in the form of a cleanser; use twice a day to treat active acne and inflammation. This ingredient may irritate skin, so discontinue use if any irritation develops.
Glycolic acid is an alpha hydroxy acid (AHA) that works by removing dead skin cells, unclogging pores and reducing inflammation. This is effective in reducing existing blemishes, in addition to the accompanying redness and irritation associated with acne mechanica.
Glycolic acid is commonly used in chemical peels, but can also be found in OTC topical skin care products. While you can purchase glycolic acid for an at-home chemical peel at low concentrations, these treatments can have side effects, including hyperpigmentation, scarring or even infection.
For a safer option, choose a glycolic acid cream or gel with a 10% concentration. These products have been shown to significantly improve cases of mild acne. It is recommended to use your glycolic acid once per day, applying it in the evening to clean skin.
Benzoyl peroxide works by increasing the skin cell turnover rate and clearing dead skin cells, bacteria and oil from pores. OTC options include cleansers and creams, with prescription strength formulations available for more severe cases.
Cleansers that contain benzoyl peroxide are typically lathered across the impacted area for 10 to 20 seconds before being rinsed off, while creams are applied after using a mild cleanser. Some creams can be left on, others must be rinsed off after a few minutes, so be sure to follow any instructions provided with your cream.
Products containing benzoyl peroxide can effectively treat acne in as little as 5 days, however, benzoyl peroxide can irritate the skin, causing dryness and scaling. It’s also not recommended for use during pregnancy.
When adding retinol to your routine, start by applying it once per week. If you do not experience any skin irritation, increase application to every second day. As retinol increases the skin’s susceptibility to sun damage, it should only be applied in the evening.
Before applying retinol, rinse your face using warm water. Let your skin air dry for a few minutes and, once dry, apply a pea-sized amount of retinol cream to your finger tip.
Dab the cream on your chin and massage upward across your face. After application, apply a moisturizing cream. The morning after application, use an SPF cream to protect your skin from UV damage.
The side effects of retinol include burning, peeling, dry skin and stinging where it’s applied.
How to Prevent Acne Mechanica
Since this form of acne is the result of physical irritation, the best prevention is to avoid this irritation in the first place. That said, when this is impossible, there are some steps you can take to minimize irritation.
Wear clean, breathable fabrics
Fabrics such as cotton, bamboo and linen allow skin to breathe, sweat to evaporate, and heat to dissipate. Choose sports equipment designed with synthetic fabrics specifically engineered to be breathable and to draw sweat away from skin.
Additionally, it is important to wear clean clothing, because soiled clothing likely contains bacteria or sweat that will irritate skin.
Wash sports equipment after each use and, following any physical activity, be sure to remove sweaty equipment or clothing as soon as possible.
Keeping the area clean
Regularly wash the areas prone to acne mechanica using a mild cleanser. This helps to clear away any dead skin, oils, or bacteria already present on the skin so that when friction does occur, it is less likely to cause acne.
Acne-fighting cleansers, particularly salicylic and alpha hydroxy acids, can be used regularly as a preventative measure. They can be used regularly to remove excess oil, dead skin, dirt and bacteria from the skin’s surface.
Acne mechanica is a treatable and preventable form of acne caused by the buildup of bacteria in clogged pores brought on by excess heat and friction. This results in acne that appears similar to rash for mild cases but can develop into severe inflammatory acne. Tight clothing and sports equipment are some of the most common contributors to the development of acne mechanica.
Effective treatment includes minimizing or eliminating repeated friction in vulnerable areas, and applying a topical cream or cleanser with salicylic or glycolic acid, benzoyl peroxide or retinol. This will serve to clear up existing acne and reduce the risk of worsening acne.
To prevent acne mechanica from occurring, wear loose, breathable fabrics to avoid friction and trapping heat and moisture. It is equally important to maintain hygiene: wash often, and change clothes and equipment regularly in order to avoid the buildup of any bacteria.
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