Acne and rosacea are the two most common facial inflammatory conditions — and among the most commonly confused. The single most important distinguishing feature is the presence or absence of comedones. Comedones are present in acne. They are absent in rosacea. This one finding changes the entire treatment approach.
CLINICAL PRINTABLE
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A one-page Acne / Rosacea clinical reference is on the way.
- Acne vulgaris: comedones (open/closed), inflammatory papules, pustules, nodules, and cysts. Primarily affects face, chest, and back. Driven by follicular plugging, sebum overproduction, Cutibacterium acnes colonization, and inflammation.
- Acne severity: mild (comedones + few papules/pustules), moderate (multiple papules/pustules ± nodules), severe (nodules, cysts, scarring risk). Severity guides treatment intensity.
- Rosacea: central facial erythema, telangiectasias, flushing, papules and pustules WITHOUT comedones. Four subtypes: erythematotelangiectatic, papulopustular, phymatous, ocular.
- Rosacea triggers: heat, sun, spicy food, alcohol, exercise, emotional stress, hot beverages, certain skincare products. Identifying and avoiding triggers is a core management strategy.
- Key distinguishing feature: comedones are present in acne, absent in rosacea. This single finding guides the diagnosis when the presentation is ambiguous.
Perioral dermatitis
Papules and pustules around the mouth and nose — often triggered or worsened by topical corticosteroids. Treat by stopping the steroid; may flare initially.
Seborrheic dermatitis
Greasy, yellowish scale on the nasolabial folds, eyebrows, and scalp. Responds to antifungal agents, not acne treatment.
Folliculitis
Pustules centered on hair follicles, often on the trunk or extremities. May be bacterial (S. aureus) or fungal (Malassezia). Culture guides treatment.
Lupus malar rash
Butterfly-shaped erythema across the cheeks and nose, sparing the nasolabial folds. Associated with systemic symptoms and positive ANA.
Acne — Mild (comedonal/few inflammatory)
Topical retinoid (tretinoin, adapalene) as the cornerstone — normalizes follicular keratinization and prevents new comedone formation. Add benzoyl peroxide for antimicrobial effect. Avoid topical antibiotic monotherapy due to resistance.
Acne — Moderate (multiple papules/pustules)
Topical retinoid plus benzoyl peroxide plus topical antibiotic (clindamycin or erythromycin — always combined with BP to reduce resistance). Oral antibiotics (doxycycline or minocycline) for moderate-severe or truncal acne.
Acne — Severe (nodular/cystic, scarring)
Oral isotretinoin for severe nodular acne or acne causing scarring. Requires iPLEDGE enrollment due to teratogenicity. Monthly monitoring: CBC, LFTs, lipids, pregnancy test. Course typically 4–6 months.
Acne — Hormonal (adult female, perimenstrual flares)
Combined oral contraceptives (FDA-approved: norgestimate/EE, norethindrone/EE, drospirenone/EE) or spironolactone 50–100 mg daily. Spironolactone is highly effective for hormonal acne in adult women.
Rosacea — Erythematotelangiectatic subtype
Trigger avoidance is the foundation. Topical brimonidine or oxymetazoline for acute flushing/erythema. Laser/IPL for persistent telangiectasias. Gentle skincare and broad-spectrum SPF 30+ daily.
Rosacea — Papulopustular subtype
Topical metronidazole, azelaic acid, or ivermectin cream as first-line. Oral doxycycline 40 mg (sub-antimicrobial dose) for moderate-severe papulopustular rosacea. Avoid topical steroids — they worsen rosacea.
Rosacea — Ocular subtype
Lid hygiene, warm compresses, artificial tears. Oral doxycycline for moderate-severe ocular rosacea. Ophthalmology referral for corneal involvement.
- Acne: topical retinoids take 8–12 weeks for visible improvement — counsel patients to continue through the initial purging phase (weeks 2–6) when acne may temporarily worsen.
- Oral antibiotics for acne: reassess at 3 months. If no improvement, reconsider diagnosis, adherence, and resistance. Do not continue oral antibiotics indefinitely — transition to topical maintenance.
- Isotretinoin: cumulative dose of 120–150 mg/kg determines course length. Expect initial flare in first 4–6 weeks. Dryness, cheilitis, and photosensitivity are expected side effects.
- Rosacea: topical agents reduce papules and pustules over 8–12 weeks. Erythema and flushing are harder to treat — trigger avoidance and laser are more effective than topical agents for vascular features.
- Dermatology referral for severe nodular/cystic acne (isotretinoin initiation), acne with significant scarring, treatment-resistant acne, or diagnostic uncertainty.
- Rosacea with phymatous changes (rhinophyma) requires dermatology or plastic surgery referral for surgical or laser debulking.
- Ocular rosacea with corneal involvement: urgent ophthalmology referral to prevent corneal scarring and vision loss.
- Acne fulminans: sudden-onset severe ulcerative acne with systemic symptoms (fever, arthralgia) — urgent dermatology referral. Oral corticosteroids before isotretinoin.
APPLY IT
A 22-year-old woman has inflammatory papules and pustules on her cheeks and chin, worse before her period. No comedones. Her skin is red and she flushes easily with wine and spicy food. This is rosacea, not acne — the absence of comedones and the flushing pattern are the key findings. Treating with benzoyl peroxide and topical antibiotics will not address the underlying vascular reactivity.
CHANGE ONE DETAIL
Change one detail — the same patient has blackheads and whiteheads along with the papules, and the flushing is absent. Now this is acne. The treatment shifts to topical retinoid plus benzoyl peroxide. The comedones are the distinguishing feature.
Bottom Line
Comedones are present in acne, absent in rosacea. Topical steroids worsen rosacea. Retinoids are the cornerstone of acne; trigger avoidance is the cornerstone of rosacea.
EVIDENCE & REFERENCES
- Zaenglein AL, et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol. 2016;74(5):945-973. doi:10.1016/j.jaad.2015.12.037
- Thiboutot DM, et al. New insights into the management of acne: an update from the Global Alliance to Improve Outcomes in Acne group. J Am Acad Dermatol. 2009;60(5 Suppl):S1-50. doi:10.1016/j.jaad.2009.01.019
- Gallo RL, et al. Standard classification and pathophysiology of rosacea: The 2017 update by the National Rosacea Society Expert Committee. J Am Acad Dermatol. 2018;78(1):148-155. doi:10.1016/j.jaad.2017.08.037