Sweat Pimples: Causes, Treatment and Prevention

• Sweat pimples are a common skin response to excessive heat, sweating or exercise. 
• While uncomfortable, there are no long-term effects or scarring. 
• Symptoms can be reduced by keeping the affected area clean, wearing loose clothing and applying acne-fighting ingredients such as salicylic acid, benzoyl peroxide and retinoids.
• Sweat pimples appear similar to other skin conditions like miliaria and acne inversa. 

Sweat pimples are a common skin condition seen in those with both normal and acne-prone skin. A red, inflamed or itchy rash often develops after exercise or excessive sweating. Small blisters or mild pustules under the skin may resemble sweat bubbles (small white or clear-filled blisters) or hardened bumps.

What Causes Sweat Pimples?

A healthy sweat is beneficial for skin; it opens up the pores and sweeps out any trapped dirt, bacteria or oil that can cause acne. However, allowing sweat to dry on your skin can have the opposite effect – it can clog pores and cause sweat pimples.

Your skin’s surface features a complex relationship of pH, moisture, temperature, sebum content and sweat. These make it an ideal habitat for a wide range of microorganisms, some beneficial, some not. 

When you perspire, your body releases liquid (comprised of water, ammonia, urea, salts and sugar) from your eccrine sweat glands to help cool you down. Sweat pimples are more likely to occur if you let this liquid remain on your skin because it traps oil and dirt, and allows harmful bacteria to multiply beneath it. 

When you combine sweat with friction on the skin, the result is a condition known as acne mechanica. It can occur in those without a pre-existing acne diagnosis. It’s also common in patients confined to bed or chair rest, or where a prosthetic limb presses against the skin.

Acne mechanica can develop in athletes and those who regularly engage in sports. Equipment such as helmets, bike shorts, hats, tight gym wear or headbands create additional pressure on the skin, causing tender lesions filled with trapped sweat that can burst when rubbed. 

Where do sweat pimples occur? 

Sweat pimples occur in the areas where you perspire the most. You have more sweat glands on your forehead, in your armpits and in the groin area, where the body needs to control temperature most. 

However, sweat pimples can also develop anywhere your skin comes into regular contact with external objects such as backpacks, clothing, hat rims and belts.

Tight gym clothes are a main culprit because they trap sweat close to the skin on the back, chest or thighs, clogging pores more readily.

Places you are more likely to experience sweat pimples include:

• The face
• The neck
• The armpits
• Beneath the breasts
• Between skin folds 
• The groin area 

Are you predisposed to sweat pimples?

Some people are more prone to developing sweat pimples than others: 

• Acne – If you suffer from acne vulgaris, your skin is more susceptible to irritation; if you also sweat excessively, you’re more likely to experience sweat pimples.
• Obesity – Moist skin folds are common in overweight people, and are the ideal environment for sweat pimples to develop and thrive.
• Gender – Men sweat more than women. Even though women have the same number of sweat glands, men produce more sweat, whether training hard or not. This is because women’s sweat glands require a higher body temperature than men’s to activate.

How to Treat Sweat Pimples

Keeping your skin cool whenever possible and wearing loose-fitting clothes is a first step in a treatment plan. Occasional instances of sweat pimples will likely resolve once your body cools down. You may also try other simple remedies:

• Gently wash the affected area with antibacterial soap, if tolerated. Ensure you don’t scrub or exfoliate the rash site. Don’t overwash as this action can dry out the skin and cause further irritation.
• Resist touching, squeezing or picking at sweat pimples. This can transfer bacteria from your hands to the site and induce further infection. 

Ingredients to look for

For recurring bouts of sweat pimples, over-the-counter products that target, soothe and resolve acne may be required. Look for lotions, body washes and moisturizing creams that include the following ingredients to achieve the best results.

Salicylic Acid

Salicylic acid is an oil-soluble hydroxy acid that can remove dead skin cells and promote faster healing of sweat pimples. It can penetrate into pores and dissolve the intercellular glue that holds skin cells together, loosening and removing dead skin cells, and dissolving blackheads. 

The result is deep cleansing and exfoliation. Salicylic acid can also reduce sebum secretion and is valued for its anti-inflammatory properties, helping to prevent cells from becoming clogged with debris and calming red, irritated skin.

Benzoyl Peroxide

Benzoyl peroxide has strong acne-fighting properties to remove excess skin oils and dead skin cells; it also kills bacteria. This can be an effective treatment for sweat pimples that have developed mild pustules. However, It’s more drying than salicylic acid, so it may cause greater skin irritation.

Benzoyl peroxide is a free radical that can effectively target bacteria, as well as sebaceous gland and hair follicle inflammation. It works by breaking down keratin, promoting sebum drainage, and preventing new pimples from forming.

Retinoids

Retinoids are powerful anti-aging and anti-acne treatments that clear blocked pores and increase skin cell turnover. They also inhibit the immune system’s response to sweat pimples, which reduces the size of the breakout.

Mild retinoid products such as retinol, are available over the counter, but for persistent sweat pimples you may need a stronger formulation available through a prescription from your dermatologist. Side effects include sun sensitivity, redness, irritation and flaking; apply sunscreen after use.

Tips to Prevent Sweat Pimples

The key to avoiding sweat pimples is to pay particular attention to hygiene—before and after exercising—to maintain clean pores.  If you are prone to developing sweat pimples, avoid intense heat and humidity whenever possible.

• Remove makeup before your workout (or other scenarios in which you normally sweat) to keep pores open
• Shower immediately after exercising or excessive sweating
• Change into fresh, clean clothes to avoid trapping dirt, oil, and sweat close to the skin
• Use oil-free moisturizing products and cleansers to avoid clogging pores further 
• Keep any clothing, bedding and towels that contact your skin scrupulously clean
• Drink plenty of water to hydrate skin and to maintain a cool body temperature
• During the hottest times of the day, seek cool spaces with low humidity 

Conditions Similar to Sweat Pimples

Other conditions caused by excessive sweating appear similar to sweat pimples. They are often confused with a group of heat rashes medically termed miliaria, that range from mild to severe.

Miliaria

Caused by sweat duct blockages, the miliara group of skin conditions often appear as clusters of red bumps filled with white or clear fluid. Affected areas include the neck, upper torso, groin, waistline, armpits and skin folds.

There are three types of miliaria:

• Miliaria crystallina features superficial white or clear marks filled with sweat caused by a temporary obstruction of eccrine sweat ducts; they don’t become inflamed or itchy 
• Miliaria rubra (prickly heat or sweat rash) is caused by trapped sweat, which triggers a tiny, inflamed papules
• Miliaria profunda is a rare condition that occurs during exposure to intense heat; painful, deep red or white nodules develop. 

How to differentiate between miliaria and sweat pimples: 

• Miliaria does not develop around hair follicles 
• Miliaria sufferers can develop fever and heat stress if a large surface area of skin is affected.

Blocked hair follicles

Blocked hair follicles can also appear similar to sweat pimples but are a far more serious, chronic condition. When painful pimple-like abscesses form under the skin, become infected and scar, it’s called hidradenitis suppurativa (HS) or acne inversa. 

As with sweat pimples, HS develops where skin rubs together. Experts still don’t know what causes it, except it is understood to be an autoimmune reaction.

Takeaway

Sweat pimples are a common skin condition caused by exposure to heat, excessive sweating or friction against the skin. They create discomfort but rarely have lasting effects. 

Some people are more prone to developing sweat pimples, including acne sufferers, those who sweat profusely, and wear restrictive clothing. Athletes,long-term hospital patients and overweight individuals are also more susceptible.

Fortunately, sweat pimples can be prevented by wearing loose clothing, removing makeup before exercising and showering afterward. To treat sweat pimples, apply benzoyl peroxide, salicylic acid or retinol to the affected area to clean the pores and help prevent future breakouts.