Acne on Legs: Causes, Treatment, Similar Conditions and More

• Acne can develop on the legs for the same reasons it does elsewhere on the body
• Acne that is caused by friction and pressure is called acne mechanica
• Legs are particularly vulnerable to acne mechanica due to tight-fitting jeans, tights and leggings
• Other inflammatory skin conditions and infections can mimic the signs of leg acne such as folliculitis or keratosis pilaris

Acne develops due to an accumulation of sebum, dead skin cells and debris within hair follicles which causes whiteheads and blackheads. When Cutibacterium acnes bacteria accumulates, this results in inflamed pus-filled lesions. These pimples most often develop in areas rich in sebaceous glands such as the face, chest, upper back and shoulders; however, acne on the legs is also common.

Do You Have Acne on Your Legs? 

Whiteheads and blackheads are hard plugs of debris that form within hair follicles; they will appear white or off-white, or have a darkened tip. These pimples represent noninflammatory acne and as such, are not red, swollen or painful. 

In order of severity, inflamed lesions can take the form of papules, pustules and cysts, progressing from tender, solid red bumps, to painful, inflamed pus-filled boils. If left untreated the infection can spread and worsen. 

Acne on the legs can be mild, moderate or severe; it can be inflamed or noninflamed or a combination of both.

Common Causes  

There are a number of established causes for acne including hormonal fluctuations, genetics, stress, diet and medication.

What is common among all these causes is that they all influence sebaceous gland activity by stimulating these glands to overproduce, leading to excess oiliness and new or worsening acne breakouts. 

Acne on the legs can also be brought on by a combination of heat, pressure and friction; when this is the case, the acne is called acne mechanica. In addition to pimples, common symptoms include redness, irritation and sensitivity.

As with other areas of the body, acne mechanica varies in appearance from comedones (blackheads and whiteheads) to inflamed lesions depending on the severity and the stage of its progression.

Tight-fitting clothes—jeans, tights, leggings and undergarments—can cause irritation by constantly rubbing against skin. So too can synthetic materials as they contain dyes and chemicals; they also don’t absorb perspiration, leaving it to accumulate on your legs.

Tight clothing also traps heat, oil and debris creating an ideal environment for bacteria to thrive in. The result is the formation of comedones and if left untreated, inflamed pimples. 

Treatments for Leg Acne

The first step is to remove the source of friction; exchange form-fitting pants for those that are looser, made of cotton and allow the skin to breath. Change your clothes often to keep debris, dead skin cells, oils and perspiration away from your skin. 

Acne treatment will be contingent on whether you have inflamed or noninflamed lesions or a combination. Both types can benefit from the following prescribed and over-the-counter treatments.

Antibiotics

Topical antibiotics may be prescribed for mild-to-severe inflamed lesions to kill acne-causing bacteria and reduce inflammation. This alleviates redness, swelling, irritation and pain and helps lesions heal faster.

Topical antibiotics can also have a mild comedolytic effect, making this medication appropriate for both inflammatory and noninflammatory acne.

Two commonly prescribed topicals are erythromycin and clindamycin; these are available in solutions, lotions, gels and saturated pads.

Due to the increasing threat of bacterial resistance, antibiotics are commonly used alongside other agents, such as benzoyl peroxide, another potent agent; in addition, combining both brings enhanced results. 

Benzoyl peroxide 

Benzoyl peroxide is a mainstay treatment in acne therapy as it is an antibacterial that can deeply penetrate to unclog pores and slough off dead skin cells and debris.  

This agent is particularly effective for inflammatory acne due to its efficacy in killing acne-causing bacteria to alleviate swelling and redness, and to help heal lesions. However, it has also been shown to moderately reduce noninflammatory acne lesions and inhibit bacterial growth to prevent mild acne from progressing to inflamed acne.

Benzoyl peroxide is available OTC in multiple forms including cleansers, body washes, foams, gels, toners, lotions and creams. You can also obtain a prescription-strength product from your dermatologist.  

In cases of leg acne, benzoyl peroxide products can be used all over or as a spot treatment to target a specific area.

Glycolic acid

Glycolic acid is a gentle alpha-hydroxy acid (AHA) that has many qualities to treat and prevent acne on the legs. 

This chemical exfoliant has a very small molecular size, which enables easy penetration of the skin barrier. As a keratolytic, it can dissolve the bonds that hold dead skin cells together and exfoliate the top layer of skin to clear away excess oils, flakiness, grime and debris.

As a humectant it can help draw in and retain moisture to repair and strengthen the skin barrier. This is especially vital for acne-prone skin as acne products tend to have a drying effect.   

Lastly, this acid has been shown to have antibacterial activity to keep bacteria levels in check. 

Salicylic acid 

Salicylic acid is an oil-soluble, beta hydroxy acid (BHA) that can help with inflamed lesions but is most effective against comedones. This is because it can penetrate pores to effectively break down and dissolve the sebum and dead skin cells that cause comedones.

Like glycolic acid, salicylic acid is also a keratolytic; it’s also valued for its ability to regulate sebum production and kill bacteria. 

Both glycolic and salicylic acid perform the same functions but the former may be a better choice for dry and sensitive skin; the latter is the more powerful of the two and is best for oily skin as it can regulate oil production.

Similar Conditions

Other inflammatory skin conditions and infections can easily be confused for acne as they may share similar symptoms.

Eczema

Atopic dermatitis, or eczema, is chronic skin disease that results from a combination of genetic and environmental factors and is usually triggered by an allergic reaction or very dry skin. 

Symptoms include a blotchy red rash that can be raised and bumpy in appearance. Unlike acne on the legs, eczema can be intensely itchy which leads to scratching and increased risk of infection. When infected, fluid-filled blisters develop, weep and crust over.

Eczema can develop anywhere on the legs but typically does so behind the knees where the skin flexes.

Folliculitis

Folliculitis is a common skin condition that develops when hair follicles become damaged or blocked and then become vulnerable to a staph infection, usually Staphylococcus aureus or when exposed to Pseudomonas aeruginosa bacteria which thrives in hot tubs and whirlpools. 

Improper hair removal techniques, including waxing and shaving, or ingrown hairs can damage hair follicles and enable bacteria to enter and multiply. As with acne mechanica, it can also result from steady friction against the legs. 

Folliculitis looks like acne – pimple-like red bumps or white fluid-filled pustules. This condition differs from acne in that it causes greater discomfort in terms of itchiness and pain.

Hives    

Hives develop when the body’s immune system releases histamine in response to a perceived threat (such as insect stings or bites, specific foods, medication, pollen or pet dander) causing an allergic reaction. 

Hives are raised, red bumps (wheals) that may present with swelling and could easily be mistaken for acne. However this condition differs in that hives can be intensely itchy and may cause burning and stinging. As well, wheals typically fade within 2–8 hours, unlike acne lesions.

Keratosis pilaris

Keratosis pilaris is a genetic disorder that is characterized by a buildup of keratin, a protein that  protects the outer layer of skin. This buildup blocks pores and results in the formation of patches of dry rough skin and small bumps, similar to goosebumps. These bumps are painless and usually skin-colored.

While keratosis pilaris may look similar to acne and is a result of blocked pores, it does not cause itching, discomfort or inflammation. Like acne mechanica, it can develop on the legs and especially the thighs.

Takeaway

Leg acne develops for the same reason it does elsewhere on the body – due to an accumulation of excess oil, dead skin cells and debris to cause comedonal acne and if left untreated, inflammatory acne. 

Acne on the legs is also common due to the combination of heat, perspiration, friction and pressure that can result from too-tight clothing. This skin condition is called acne mechanica.

Treatment options include antibiotics to kill the bacteria and reduce the uncomfortable symptoms of swelling, redness and irritation. Antibiotics can also help heal active lesions.

Benzoyl peroxide is commonly used as a sole treatment and alongside antibiotics to better treat inflammatory acne. Both glycolic and salicylic acid slough off dead skin cells and penetrate pores to clear away pore-clogging debris and exfoliate the outer layer of skin.

Other skin conditions and infections can resemble acne such as eczema folliculitis, hives, eczema and keratosis pilaris. If you are unsure as to what is causing lesions or irritation on your legs, see your dermatologist for an assessment of your skin.