Acne vulgaris vs Rosacea and folliculitis
How to tell Acne vulgaris and Rosacea and folliculitis apart when a board question makes them look alike.
Acne has comedones; rosacea has flushing/telangiectasia without comedones; folliculitis is follicle-centered pustules.
Side by side
Acne vulgaris causes comedones, inflammatory papules, pustules, nodules, and scarring on sebaceous areas, often in adolescents.
Rosacea causes centrofacial flushing, telangiectasia, papules/pustules without comedones, and ocular symptoms; folliculitis causes follicle-centered pustules from infection or irritation.
Follicular plugging, sebum, Cutibacterium acnes, and inflammation drive acne lesions.
Rosacea involves vascular/neuroimmune facial inflammation; folliculitis is inflammation or infection centered on hair follicles.
Open and closed comedones support acne vulgaris.
Telangiectatic flushing without comedones supports rosacea; follicle-centered pustules support folliculitis.
The trap
Papules and pustules overlap, so comedones, flushing, telangiectasia, and follicular centering separate them.
The repair move
For acne-like eruptions, look for comedones first, then flushing or follicular centering.
Try a free question
CoreA 17-year-old boy has 1 year of pimples on the forehead, cheeks, and chin. Exam shows open and closed comedones, inflammatory papules and pustules, and a few cystic nodules. The lesions are centered on hair follicles. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Acne vulgaris. Acne vulgaris is a multifactorial pilosebaceous disorder with comedones (open and closed), inflammatory papules and pustules, and sometimes nodules/cysts; pathogenesis involves follicular hyperkeratosis, Cutibacterium (Propionibacterium) acnes, sebum overproduction, and inflammation; treatment escalates from topical retinoids and benzoyl peroxide to oral antibiotics and isotretinoin.
Why the other choices are tempting
- B. Rosacea has flushing, telangiectasias, papules and pustules, and rhinophyma WITHOUT comedones.
- C. Folliculitis is bacterial follicular pustules without comedones (often Staphylococcus aureus).
- D. Perioral dermatitis is small papules around the mouth often after topical corticosteroid use.
- E. Pseudofolliculitis barbae is ingrown facial hairs in shaved beard area.
Flashcards
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What lesion supports acne vulgaris?
Open or closed comedones support acne vulgaris and argue against rosacea or simple folliculitis.
What feature argues against acne and toward rosacea?
Facial flushing with telangiectasia and no comedones supports rosacea rather than acne vulgaris.
Quick answers
What is the fastest way to tell Acne vulgaris from Rosacea and folliculitis?
Acne has comedones; rosacea has flushing/telangiectasia without comedones; folliculitis is follicle-centered pustules.
What is the key clue for Acne vulgaris?
Acne vulgaris causes comedones, inflammatory papules, pustules, nodules, and scarring on sebaceous areas, often in adolescents.
What is the key clue for Rosacea and folliculitis?
Rosacea causes centrofacial flushing, telangiectasia, papules/pustules without comedones, and ocular symptoms; folliculitis causes follicle-centered pustules from infection or irritation.
What is the common trap with Acne vulgaris vs Rosacea and folliculitis?
Papules and pustules overlap, so comedones, flushing, telangiectasia, and follicular centering separate them.