Skin Health Acne An Overview of Comedones and Comedonal Acne By Heather L. Brannon, MD Heather L. Brannon, MD Heather L. Brannon, MD, is a family practice physician in Mauldin, South Carolina. She has been in practice for over 20 years. Learn about our editorial process Updated on March 25, 2022 Medically reviewed by Leah Ansell, MD Medically reviewed by Leah Ansell, MD LinkedIn Leah Ansell, MD, is a board-certified dermatologist and an assistant professor of dermatology at Columbia University. Learn about our Medical Expert Board Print Table of Contents View All Table of Contents Symptoms Types of Comedones Causes Prevention Treatment Comedones are small flesh-colored, white, or dark bumps on your skin. They are a type of acne blemish, caused by plugs of oil and dead skin that become stuck in the openings (follicles) that enclose the roots of your hair. A single bump is called a comedo. Comedonal acne is a common type of acne that consists of comedones rather than inflamed pimples. Verywell / JR Bee Symptoms Comedonal acne doesn't look like typical "acne". Many people with comedonal acne don't realize those bumps and blemishes are, in fact, a type of acne. Comedonal acne causes few, if any, inflammatory breakouts. Instead, symptoms of acne include: Skin that looks and feels bumpy Blackheads Milia The bumps of comedonal acne aren't red like a typical pimple; instead, they're whitish or skin-colored. These bumps and blackheads are a type of non-inflamed acne blemishes called comedones. You may know comedones by the more common term pore blockage. Comedonal acne can range from mild (with just a few occasional blemishes) to more severe with many blemishes happening over large areas of skin. It can develop on your face, back, neck, shoulders, and chest. Comedones can appear on their own, or alongside inflamed acne. Overview of the Types and Stages of Acne Types of Comedones Comedones are caused by two things: skin-cell growth and increased oil production. A comedo forms when dead skin cells and oil form a plug that blocks your hair follicle. There are a number of types of comedones. Open Comedones An open comedo is what is commonly call a blackhead. It occurs when the plug of oil becomes trapped within the hair follicle near the pore opening. The top of the plug is at the surface of the skin and is exposed to air. The dark brown top of a blackhead isn't dirt trapped within the pore, but rather oil that has oxidized and darkened. The air oxidizes the oil and darkens it, similar to what happens when an apple is cut and left exposed to air. The top of the plug takes on the dark brown color typical of blackheads. If you were to gently extract the blackhead, you can see the dark top portion of the plug is dark while the lower portion that was not exposed to air is creamy white to yellow. These blackheads typically form on the sides and bridge of the nose, the chin, on the shoulders, and back. Closed Comedones Closed comedones develop when the pore opening is obstructed and the plug of oil and skin cells is not exposed to air. The hair follicle is completely blocked. The plug doesn't turn black, instead a whitish or flesh-colored a bump appears on the skin. The bump isn't red, nor inflamed, and it doesn't hurt. These whiteheads most often appear on the forehead, chin, and cheeks. What Are Closed Comedones? 1:31 Click Play to Learn More About Closed Comedones Microcomedones Microcomedones are the smallest of all acne blemishes. These comedones, invisible to the naked eye, are the "seeds" of the growth of visible comedones. Every inflamed pimple, every blackhead, begins as a microcomedo. Macrocomedones Macrocomedones are open (more common) or closed comedones that are larger than average. They typically range in size from 1 millimeter (0.04 inches) to 3 millimeters (0.12 inches ) in diameter. Giant Comedones These are huge blackheads, from several millimeters to 2 centimeters (0.78 inches) in diameter. They typically occur singly and in older adults. Solar Comedones Also called senile comedones, these lesions are caused by excessive sun exposure over time. They may be small or large, open or closed. Solar comedones most often occur in people aged 60 to 80 years, but they can occur in people in their 40s with extreme sun exposure. Types of Non-Inflamed Acne Blemishes Causes All comedones begin as a plug of sebum, or skin oil, and dead skin cells that become trapped in the follicle. This plug blocks the follicle opening. The sebaceous glands continue to pump oil into the pore, and as it fills with oil it pushes up on the skin's surface. This is what creates the bump that you can feel and see. Comedones aren't typically painful, just annoying. You can think of them as pre-pimples because all inflamed pimples get their start as a comedo. Like most types of acne, comedonal acne is especially common during the preteen and teen years. However, it can occur to anyone at nearly any age, adulthood included. Comedonal acne can be a harbinger of inflammatory acne vulgaris to come, especially when it appears during puberty. Comedones don't always progress to inflamed pimples, though, and can stay as a non-inflamed blocked pore just under the skin's surface. Comedonal acne tends to run in families. If your parents or siblings had it, you're more likely to have it too. People with oily skin are more prone to comedonal acne as well. What Makes Acne Worse Many things can make acne progress and worsen. They include: Changing hormone levels during puberty, or in females the week before their periods How the Menstrual Cycle Affects Acne Skin pressure or friction from, for example, tight collars, backpacks, helmets, or other sporting equipment (causing a specific type of acne called acne mechanica) Oily cosmetic products such as moisturizers and hair pomades Air pollution High humidity Squeezing pimples or picking at them Scrubbing skin too hard Preventing Comedones In many cases, minor comedones can be prevented (or at the least reduced). There are a few steps you can take to keep pore blockages away: Wash any acne-prone skin areas only twice a day. Additional washing may irritate your skin.Use oil-free and noncomedogenic skin products for washing, moisturizing, and makeup as these are less likely to clog your pores.Keep all your makeup brushes and applicators clean.Gently remove all makeup before you go to bed.Don’t let perspiration and oil stay on your skin. Take a shower after a workout or other strenuous physical activity. Some people are prone to developing comedones, even with exceptional skincare. In this case, over-the-counter acne products or prescription medications are needed to keep comedones from forming. Treatment Just like other types of acne, comedonal breakouts aren't caused by a lack of hygiene. Scrubbing your skin or washing your face more often isn't going to be enough to clear up your skin. While a consistent daily skincare routine is an important component to healthy skin, know that good skincare alone probably won't clear your skin. There are plenty of treatments that will, though, which are available both over the counter and by prescription. Some common treatments for comedonal acne include: Salicylic acid Benzoyl peroxide Differin (adapalene) Topical retinoids Azelaic acid If your acne is mild, you may be able to treat it with over-the-counter (OTC) treatments. For more severe and persistent acne, it's a good idea to see your healthcare provider to discuss treatment options. With any treatment, it can take up to 12 weeks to see an improvement. Stick with it, even if you don't notice any immediate signs that it's working. Talk to a dermatologist if you're not seeing good results after three months of treatment. OTC and Prescription Treatments for Comedonal Acne A Word From Verywell As with all types of acne, it's best to treat comedonal acne as soon as possible. For minor blemishes, OTC products are often enough to do the trick. More severe, widespread, or long-lasting cases can be treated effectively with prescription medications. It will take time to notice the benefits of new treatments, so be patient and talk to your healthcare provider if you have any concerns or questions. Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Gollnick HP, Zouboulis CC. Not all acne is acne vulgaris. Dtsch Arztebl Int. 2014 Apr 25;111(17):301-12. doi:10.3238/arztebl.2014.0301 Microcomedones. National Center for Biotechnology Information, U.S. National Library of Medicine. 2016. Oge' LK, Broussard A, Marshall MD. Acne Vulgaris: Diagnosis and Treatment. Am Fam Physician. 2019 Oct 15;100(8):475-484. Saurat JH. Strategic Targets in Acne: The Comedone Switch in Question. Dermatology. 2015;231(2):105-11. doi:10.1159/000382031 By Heather L. Brannon, MD Heather L. Brannon, MD, is a family practice physician in Mauldin, South Carolina. She has been in practice for over 20 years. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit