---
title: "Comedone — Glossary | School of Dermatology"
description: "Understand what comedones (blackheads and whiteheads) are, how they form, and which skincare ingredients effectively treat and prevent them."
lang: en
json-ld: |
  [
    {
      "@context": "https://schema.org",
      "@type": "DefinedTerm",
      "name": "Comedone",
      "description": "A comedone is a basic acne lesion formed when a hair follicle becomes clogged with dead skin cells, sebum, and sometimes bacteria. There are two types: open comedones (blackheads), where the clogged pore remains open and the trapped material oxidizes, turning dark, and closed comedones (whiteheads), where the pore opening is covered by a thin layer of skin, creating a small, flesh-colored or white bump. Comedones are considered non-inflammatory acne but can progress to inflammatory lesions (papules, pustules, or cysts) if bacteria colonize the clogged pore. Ingredients like salicylic acid, retinoids, and AHAs are effective at preventing and treating comedones by promoting cell turnover and keeping pores clear. Regular, gentle exfoliation is key to managing comedonal acne.",
      "url": "https://schoolofdermatology.com/glossary/comedone",
      "inDefinedTermSet": {
        "@type": "DefinedTermSet",
        "name": "School of Dermatology Skincare Glossary",
        "url": "https://schoolofdermatology.com/glossary"
      }
    },
    {
      "@context": "https://schema.org",
      "@type": "BreadcrumbList",
      "itemListElement": [
        {
          "@type": "ListItem",
          "position": 1,
          "name": "Home",
          "item": "https://schoolofdermatology.com"
        },
        {
          "@type": "ListItem",
          "position": 2,
          "name": "Glossary",
          "item": "https://schoolofdermatology.com/glossary"
        },
        {
          "@type": "ListItem",
          "position": 3,
          "name": "Comedone",
          "item": "https://schoolofdermatology.com/glossary/comedone"
        }
      ]
    }
  ]
---

[![School of Dermatology](/assets/logo-AGZDufdq.svg)](/)

Articles

[Skin Types](/skin-types)

Tools

[Glossary](/glossary)

[Home](/)/ [Glossary](/glossary)/ Comedone 

Glossary 

# Comedone

KOM-eh-dohn 

## Definition

A comedone is a basic acne lesion formed when a hair follicle becomes clogged with dead skin cells, sebum, and sometimes bacteria. There are two types: open comedones (blackheads), where the clogged pore remains open and the trapped material oxidizes, turning dark, and closed comedones (whiteheads), where the pore opening is covered by a thin layer of skin, creating a small, flesh-colored or white bump. Comedones are considered non-inflammatory acne but can progress to inflammatory lesions (papules, pustules, or cysts) if bacteria colonize the clogged pore. Ingredients like salicylic acid, retinoids, and AHAs are effective at preventing and treating comedones by promoting cell turnover and keeping pores clear. Regular, gentle exfoliation is key to managing comedonal acne.

## Related Terms

[Comedogenic](/glossary/comedogenic)[Whiteheads](/glossary/whiteheads)[BHA (Beta Hydroxy Acid)](/glossary/bha-beta-hydroxy-acid)[Retinoid](/glossary/retinoid)[Sebum](/glossary/sebum)

Was this definition helpful?

In This Entry

[Definition](#definition)[Related Terms](#related-terms)

More "C" Terms

[Ceramides](/glossary/ceramides)[Chemical Exfoliant](/glossary/chemical-exfoliant)[Collagen](/glossary/collagen)[Comedogenic](/glossary/comedogenic)[Contact Dermatitis](/glossary/contact-dermatitis)[Cystic Acne](/glossary/cystic-acne)

#### Ingredients

-   [Browse All](/topics/ingredients)

#### Treatments

-   [Browse All](/topics/treatments)

#### Skin Concerns

-   [Browse All](/topics/skin-concerns)

#### Light Therapy

-   [Browse All](/topics/light-therapy)

#### Skin Care

-   [Browse All](/topics/skin-care)

#### Hair Care

-   [Browse All](/topics/hair-care)

#### Resources

-   [Skincare Glossary](/glossary)
-   [All Articles](/articles)
-   [Contact Us](/contact)

© 2026 School of Dermatology. All rights reserved. For educational purposes only.

[Privacy Policy](/privacy-policy)[Terms of Service](/terms-of-service)[Disclaimer](/disclaimer)

![](https://bat.bing.com/action/0?ti=343074860&Ver=2&mid=bc8e8a6a-9d23-4b9a-8a34-79e6b48af4ae&bo=1&sid=02cf7f30abc711f1881cb7280e8610ef&vid=02cfa770abc711f18904e709822395dc&vids=1&msclkid=N&pi=918639831&lg=en-US&sw=800&sh=600&sc=24&nwd=1&tl=Comedone%20%E2%80%94%20Glossary%20%7C%20School%20of%20Dermatology&p=https%3A%2F%2Fderm-school-hub.lovable.app%2Fglossary%2Fcomedone&r=&lt=1290&evt=pageLoad&sv=2&cdb=AQAQ&rn=781553)

![](https://bat.bing.com/action/0?ti=343220809&Ver=2&mid=0a1a94d2-15e3-415d-a8fa-3adfbb45a080&bo=1&sid=02cf7f30abc711f1881cb7280e8610ef&vid=02cfa770abc711f18904e709822395dc&vids=0&msclkid=N&pi=918639831&lg=en-US&sw=800&sh=600&sc=24&nwd=1&tl=Comedone%20%E2%80%94%20Glossary%20%7C%20School%20of%20Dermatology&p=https%3A%2F%2Fderm-school-hub.lovable.app%2Fglossary%2Fcomedone&r=&lt=1290&evt=pageLoad&sv=2&cdb=AQAQ&rn=974356)