Closed Comedones: What They Are and How to Treat Them

• Commonly known as whiteheads, closed comedones are mild acne lesions caused by a buildup of oil and dead skin.
• There are many factors that contribute to the formation of whiteheads including hormones, diet and certain medications.
• Over-the-counter (OTC) topical treatments, such as benzoyl peroxide, are typically effective enough to prevent and treat whiteheads. 

Closed comedones, or whiteheads, are small bumps that usually develop in areas where pores are largest and most densely concentrated such as the face, shoulders and neck. They are common, mild, noninflammatory acne lesions that can affect people of all ages and skin types.

What Are Closed Comedones?

A closed comedo forms when a pore becomes blocked by dead skin cells or other debris. Sebum, a naturally occurring oily substance that moisturizes skin, normally reaches the skin’s surface through pores. 

With the pores blocked by debris, sebum builds up and hardens, attracting a bacteria known as Propionibacterium acnes. The skin may respond to this influx of bacteria by growing over the plug and creating an airtight pocket of skin filled with P. acnes, known as a closed comedo. 

Types of closed comedones and how to identify them

A typical closed comedo is a whitehead, a small raised mound on the skin’s surface with a slightly white center. Some closed comedones do not form a visible white area and are simply small, raised areas of skin. 

As closed comedones are sealed off from the environment by a thin skin layer, this prevents the interior plug and bacteria from oxidizing, allowing them to maintain a white appearance. Comedones may be classified as microcomedones (up to 1 mm) or macrocomedones (larger than 1 mm).

Closed comedones should not be confused with pustules, which are sometimes incorrectly referred to as whiteheads. 

Pustules are inflammatory acne lesions that are typically larger than closed comedones. They contain a white or yellowish pus that can easily be mistaken for the white coloration of closed comedones. Pustules are often surrounded by a red patch of skin.   

A word about milia

Another form of skin lesion, milia, is often confused with comedones. They can be identified by their small size—about the size of a grain of sand—and hard texture. While milia can be removed with a comedone extractor, they are not considered comedones.

Closed comedones vs. open comedones

Both closed and open comedones form in much the same way. Following a clogged pore, sebum is unable to reach the surface of the skin and builds up, attracting bacteria. 

Where the two types of comedones differ is in the body’s response. A closed comedo is formed when skin grows over a plug; when skin does not envelop the blockage, it is referred to as an open comedo. Open comedones, also known as blackheads, are exposed to the air, which oxidizes the clog and darkens its color. 

What Causes Closed Comedones?

There are a number of factors that can contribute to the formation of closed comedones. These include causes that can easily be controlled such as habits and diet, as well as factors that can be difficult to change such as hormonal balance.

Some elements that can cause closed comedones and that can easily be avoided include:

• Rupturing a follicle by picking a pimple
• Overapplication of moisturizers
• Overzealous washing
• Humid environments 
• Contact with certain chemicals, including propylene glycol, isopropyl myristate and dyes present in makeup
• A diet high in dairy, fats and sugar 
• A diet lacking linoleate, the salt form of linoleic acid which is typically found in vegetable oils 
• Smoking

Factors that can be difficult or impossible to avoid include:

• Having a high level of the hormone dihydrotestosterone (DHT)
• Hormonal fluctuations prior to menstruation
• The production of inflammatory proteins called cytokines by cells inside a pore

Topical Treatments for Closed Comedones

While a variety of treatments are available to combat closed comedones—from prescription oral medications and antibiotics to comedone extraction for persistent whiteheads—in most cases, OTC topicals can eliminate closed comedones. These topical treatments are available as gels, creams, lotions and washes.

Retinoids

Retinoids include prescription strength ingredients such as tretinoin, adapalene, tazarotene, and isotretinoin, and OTC retinol-based products. These ingredients are typically found in topical creams and gels, however, tretinoin and isotretinoin are also available as oral treatments.

While retinoids can help treat existing whiteheads, their main use is to prevent future outbreaks. Retinoids regulate the skin’s natural exfoliation rate and increase the skin’s production of collagen. This reduces the amount of dead skin cells that linger on the skin, reducing the likelihood of blackheads forming. Retinoids also tightens pores, further reducing this likelihood.

Glycolic acid

Glycolic acid is a type of alpha-hydroxy acid (AHA) that chemically exfoliates the skin and prevents dead skin cells from sticking together. This helps to prevent clogged pores and averts acne lesions.

Glycolic acid can be found in a variety of products including cleansers, toners, masks and peels. At-home glycolic acid products, that typically fall in the 8–15% strength range, can be used daily. If redness and skin irritation do occur, use can be reduced to every other day. 

Benzoyl peroxide

Benzoyl peroxide is a common treatment for mild acne that reduces skin surface bacteria and yeasts, in addition to skin inflammation. This works to both soothe existing acne and prevents further comedones from forming. 

Benzoyl peroxide is available in several forms, including gels, creams, lotions and washes. It is sometimes combined with other medications to bolster its effectiveness. 

Azelaic acid

Azelaic acid is a naturally occurring acid made by a type of yeast present on the skin. It reduces the growth of bacteria within hair follicles, reestablishes normal growth of skin cells that line follicles and reduces inflammation. 

Azelaic acid is often combined with oral antibiotics or hormone therapy to treat mild and moderate acne, including comedones. It is usually available in cream form.

Salicylic acid

Salicylic acid works by breaking down keratin. It is sometimes prescribed by dermatologists because it can reduce the rate at which cells within the hair follicles shed, in turn preventing them from clogging. 

Many salicylic acid preparations are available OTC, but some are only available by prescription. It is available in many forms including gels, lotions, creams and shampoos.

A word about medication

In most cases it is best to try OTC topical treatments for closed comedones before resorting to prescription medications.

When OTC options are unable to treat closed comedones, hormonal therapy may help to regulate the body’s hormonal balance and reduce the formation of closed comedones. Some hormones, such as estrogen, are known to suppress the production of sebum, which can help to minimize the appearance of closed comedones. This is particularly helpful for menstruating women that experience a rapid fluctuation in hormone levels.

Isotretinoin can also be effective in combating moderate to severe acne. However, this drug should only be prescribed as a last resort due to its potential side effects which include suicidal thoughts, depression and stroke.  

DIY At-Home Closed Comedone Treatments

While many OTC whitehead treatments are recommended by dermatologists for use at home, they rarely recommend natural products. The safety and efficacy of at-home remedies for closed comedones varies and many such treatments lack proper research.

Some of the most common natural treatments, such as tea tree oil and witch hazel, can be found in products that contain more traditional and effective ingredients such as salicylic acid and benzoyl peroxide. In some cases, combining these ingredients may improve the efficacy of these products. 

Closed Comedone Extraction and Other Professional Treatments

In addition to recommending or prescribing topical treatments to treat closed comedones, in rare cases dermatologists may perform a procedure to remove particularly troublesome closed comedones. 

Closed comedone extraction, involves creating incisions with a needle or blade while using the fingers to pull the skin tight. A sterile tool is then used to squeeze out any fluid. Closed comedone extraction can be effective when performed by a skilled dermatologist, however it is not a permanent solution as comedones may form again. 

This procedure is usually performed only when other treatments prove ineffective as it can cause pain and discomfort. In severe cases it can also lead to scarring.

While microdermabrasion and chemical peels may be effective for the purpose of improving skin quality, they are not an effective way to permanently remove comedones. 

Tips to Prevent Closed Comedones

In addition to avoiding common comedone causes, applying topical ointments and taking any oral medications prescribed by your dermatologist, there are additional steps you can take to prevent closed comedones from forming:

• Use oil-free makeup to minimize pore clogging
• Wash affected areas twice a day with a mild or medicated cleanser
• Exfoliate affected areas twice a week to remove dead skin
• Wash hair regularly to avoid the spread of oil and debris to the face

Speak with your dermatologist to learn more about preventing closed comedones and other types of acne.

Takeaway

Closed comedones are a mild form of acne that form when sebum and dead skin cells build up and clog pores. There are many factors that can contribute to the formation of closed comedones, from overactivity of hormones to smoking and dietary factors.

OTC topical treatments are usually effective in treating and preventing closed comedones. However, when closed comedones are accompanied by more severe forms of acne, treatment may require both oral and topical medication.