Acne vulgaris and rosacea
- Lesion
Acne starts in blocked oil glands in teenagers. Rosacea is facial flushing and pimples in adults, without blackheads.
What it is
Acne vulgaris is a disease of the pilosebaceous unit, nearly universal in adolescence, caused by four interacting factors: follicular hyperkeratinisation, androgen-driven sebum production, colonisation by Cutibacterium acnes and inflammation. Rosacea is a chronic disorder of facial vessels and follicles in adults, with flushing, persistent redness, papules and pustules, and in advanced cases tissue overgrowth of the nose (rhinophyma).
Step by step
- Androgens enlarge sebaceous glands and increase sebum.
- Follicular keratinocytes adhere abnormally and plug the infundibulum: microcomedone.
- C. acnes thrives in the trapped sebum and releases lipases and pro-inflammatory molecules.
- Innate immune activation recruits neutrophils and lymphocytes.
- The follicle ruptures, sebum and keratin leak into the dermis: inflammatory nodule and scarring.
Acne vs rosacea
| Feature | Acne vulgaris | Rosacea |
|---|---|---|
| Age | Adolescents, young adults | Middle-aged adults |
| Comedones | Present (primary lesion) | Absent |
| Flushing | No | Yes, triggered by heat, alcohol, spicy food |
| Distribution | Face, chest, back | Central face |
| Late changes | Scars | Telangiectasias, rhinophyma |
Clinical notes
- Retinoids act on keratinisation and sebum; antibiotics reduce C. acnes and inflammation.
- Severe nodulocystic acne scars and can affect mental health.
Test yourself
Think of the answer, then tap the question to see it.
What are the four factors in acne pathogenesis?
Follicular hyperkeratinisation, increased sebum (androgens), C. acnes colonisation and inflammation.
Which clinical feature separates rosacea from acne?
Rosacea lacks comedones and shows flushing and telangiectasia of the central face.
What is rhinophyma?
Sebaceous hyperplasia, fibrosis and vessel dilation of the nose in advanced rosacea.
Elsewhere in DurgiPedia
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Acne (MedlinePlus, US National Library of Medicine, 2025); Rosacea (MedlinePlus, US National Library of Medicine, 2025).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.