Comedone
Pronunciation: KOM-eh-dohn
A plugged hair follicle unit in the skin, presenting as either an open (blackhead) or closed (whitehead) lesion, characteristic of acne vulgaris.
Full Definition
A comedone is the primary lesion of acne vulgaris, formed when a hair follicle becomes obstructed with sebum, dead keratinocytes, and sometimes bacteria. An open comedone, or blackhead, has a dilated follicular opening that oxidises and darkens at the surface. A closed comedone, or whitehead, has a sealed opening and appears as a small, flesh-colored papule. Editors working on dermatology content must note the correct plural 'comedones' (not 'comedos') and distinguish the singular from the adjectival form 'comedonal.'
Usage
Usage note: Always use 'comedones' as the plural in clinical and editorial contexts. Avoid 'comedo' in patient-facing copy unless the house style specifies it.
In Context
- "The investigator recorded the total comedone count at baseline and at weeks 8 and 16." — Clinical trial report
- "Topical retinoids are first-line agents for comedonal acne and microcomedone formation." — Treatment guideline