Skin & Subcutaneous Tissue

Rosacea: subtypes and management

Clinical Overview and When to Suspect Rosacea

— Peak onset age 30–50; female predominance overall but phymatous subtype strongly male.

— Highest prevalence in Fitzpatrick I–II ("Celtic" skin), but underdiagnosed in skin of color where erythema is masked — look for warmth, burning, papulopustules, and granulomatous papules.

— Family history in ~30%; associations with migraine, IBD, anxiety, and cardiovascular risk markers.

— Dysregulated innate immunity (cathelicidin LL-37, kallikrein-5 overexpression).

— Neurovascular hyperreactivity → flushing triggered by TRPV1/TRPA1 stimuli.

— Demodex folliculorum overgrowth and Bacillus oleronius antigen contribute to papulopustular inflammation.

— Adult with recurrent "blushing," burning with sunlight, alcohol, spicy food, hot beverages, or temperature extremes.

— Centrofacial papules/pustules without comedones (key vs acne).

— Gritty, burning eyes plus facial redness (ocular rosacea — often missed).

— Progressive nasal disfigurement in an older man (rhinophyma).

— Diagnostic features (either suffices): persistent centrofacial erythema with periodic intensification OR phymatous changes.

— Major features (≥2 needed if no diagnostic feature): flushing, papules/pustules, telangiectasia, ocular manifestations.

Definition: Chronic, relapsing inflammatory facial dermatosis centered on the central face (cheeks, nose, chin, forehead, glabella) characterized by some combination of transient/persistent erythema, telangiectasia, inflammatory papulopustules, phymatous change, and ocular involvement.

Epidemiology:

Pathophysiology highlights:

When to suspect on Step 3 stems:

Diagnostic framework (2017 ROSCO phenotype-based criteria):

Board pearl: Rosacea is a clinical diagnosis — biopsy, cultures, and labs are reserved for atypical cases or to rule out lupus, sarcoid, or carcinoid. A 35-year-old with central-face flushing, telangiectasia, and pustules but no comedones is rosacea, not acne — choose topical metronidazole or ivermectin, not benzoyl peroxide as first move.

Presentation Patterns and Key History

— Erythematotelangiectatic (ETR): Persistent central erythema, prominent telangiectasias, flushing, burning/stinging with topicals; minimal papules.

— Papulopustular (PPR): Erythema plus inflammatory papules and pustules on cheeks/forehead/chin; resembles acne but no comedones.

— Phymatous: Thickened, fibrotic, sebaceous skin — rhinophyma most common; also gnatho-, oto-, meto-, blepharophyma. Predominantly men >50.

— Ocular: Lid margin telangiectasia, blepharitis, meibomian gland dysfunction, recurrent chalazia, conjunctival injection, gritty/foreign-body sensation, photophobia; can precede skin findings in 20%.

— Triggers: sun (UV most common), heat, cold wind, hot beverages, spicy food, alcohol (red wine), exercise, stress, menopause, niacin, topical steroids, vasodilators (CCBs, nitrates).

— Skincare exposures: astringents, retinoids, alpha-hydroxy acids, fluorinated steroids (steroid-induced rosacea — classic boards scenario after chronic facial corticosteroid use).

— Duration/progression: transient → fixed erythema → telangiectasia → papulopustules → phymatous remodeling.

— Eye symptoms: ask every patient — "burning, dryness, blurry vision, recurrent styes?"

— Psychosocial impact: embarrassment, social avoidance, depression — screen with PHQ-2.

— Malar rash sparing nasolabial folds + photosensitivity + arthralgias → SLE.

— Flushing with diarrhea, wheezing, right-heart murmur → carcinoid.

— Episodic flushing with HTN, palpitations, headache → pheochromocytoma.

— Comedones present → acne vulgaris.

Four classical subtypes (now treated as overlapping phenotypes):

Targeted history questions (high-yield for Step 3):

Red-flag features that argue AGAINST rosacea:

Key distinction: Steroid-induced rosacea/perioral dermatitis is precipitated by topical or inhaled corticosteroids — management is to taper and stop the steroid (rebound flare expected) and bridge with topical pimecrolimus or oral tetracycline. Continuing the steroid worsens disease long-term — a frequent Step 3 trap.

Physical Exam Findings

— Persistent erythema with flushing episodes lasting >10 minutes.

— Fine, branching telangiectasias on cheeks and nasal alae.

— Skin often dry, rough, with stinging on product application.

— Small (2–3 mm) dome-shaped erythematous papules and pinpoint pustules.

— No comedones (open/closed)— pathognomonic distinction from acne.

— Background erythema and edema; can have lymphedema in chronic disease (Morbihan disease — solid facial swelling).

— Thickened skin with patulous follicles ("orange peel"), nodularity, lobulation.

— Rhinophyma: bulbous nasal tip; rule out underlying basal cell carcinoma in atypical lesions.

— Lid margin: telangiectasia, irregularity, collarettes, inspissated meibomian glands → express with cotton-tip applicator.

— Conjunctiva: bulbar injection, papillary reaction.

— Cornea: punctate epithelial erosions on fluorescein staining; in severe disease, peripheral neovascularization, ulceration, perforation.

— Tear breakup time <10 seconds suggests evaporative dry eye from meibomian dysfunction.

— BP and HR during flush — sustained hypertension or tachycardia suggests pheochromocytoma.

— Cardiac auscultation for tricuspid regurgitation murmur (carcinoid).

— Skin elsewhere: photosensitive rash on chest/arms argues for lupus.

Distribution: Centrofacial — cheeks, nose, chin, central forehead, glabella. Spares periocular and perioral skin (helpful vs seborrheic dermatitis and perioral dermatitis).

Erythematotelangiectatic findings:

Papulopustular findings:

Phymatous findings:

Ocular exam (often neglected — high yield):

Granulomatous variant: Firm, monomorphic yellow-brown or red papules on cheeks/perioral area; biopsy shows non-caseating granulomas — distinguish from sarcoidosis and lupus miliaris disseminatus faciei.

Hemodynamic/systemic check (rule out mimics):

Board pearl: No comedones + central face + telangiectasia = rosacea. The single most discriminating exam feature on Step 3 vignettes contrasting acne and rosacea in a 40-year-old is the absence of comedones plus presence of telangiectasia.

Diagnostic Workup — Initial Evaluation

— Flushing with systemic symptoms (diarrhea, wheeze, palpitations, sweats, weight loss).

— Photodistributed rash with joint or constitutional symptoms.

— Treatment-refractory or rapidly progressive disease.

— Ulceration, scarring, or asymmetric facial nodules.

— Carcinoid syndrome: 24-hour urinary 5-HIAA (avoid bananas, pineapple, walnuts, avocado, acetaminophen 24 h prior); plasma chromogranin A as adjunct.

— Pheochromocytoma: Plasma free metanephrines (preferred) or 24-hour urinary fractionated metanephrines.

— Systemic mastocytosis: Serum tryptase (>20 ng/mL); 24-hour urinary N-methylhistamine.

— SLE: ANA, anti-dsDNA, anti-Smith, complement levels, CBC, UA.

— Dermatomyositis: CK, aldolase, anti-Mi-2, anti-MDA5.

— Sarcoidosis: Chest x-ray for hilar adenopathy, serum ACE (low sensitivity), calcium.

— Photography for objective tracking of erythema and lesion counts.

— Patient-reported outcomes: Rosacea Quality of Life (RosaQoL), Clinician Erythema Assessment (CEA), Investigator Global Assessment (IGA).

— Slit-lamp by ophthalmology if vision changes, photophobia, or corneal involvement.

— Schirmer test and tear breakup time for dry eye component.

Rosacea is a clinical diagnosis — no confirmatory lab or imaging is required in typical presentations. Step 3 questions often test the discipline of not over-ordering.

When to pursue testing — atypical features:

Targeted initial workup if mimic suspected:

Skin assessment tools (not lab):

Ocular workup if symptoms present:

Pediatric and pre-menopausal women: consider TSH and AM cortisol only if flushing has autonomic features — otherwise unnecessary.

Step 3 management: A 45-year-old woman with episodic facial flushing, diarrhea, and wheezing is not rosacea — order 24-hour urinary 5-HIAA and CT abdomen for carcinoid. Conversely, a 38-year-old with isolated central facial erythema, telangiectasia, and triggers (sun, wine) needs no labs — diagnose clinically and start topical therapy. Over-testing in classic rosacea is a wrong answer.

Diagnostic Workup — Advanced or Confirmatory Studies

— Histology shows perivascular and perifollicular lymphohistiocytic infiltrate, dilated dermal vessels, sebaceous gland hyperplasia, and dermal edema; granulomatous variant shows non-caseating granulomas.

— Use to exclude cutaneous lupus (interface dermatitis, mucin), sarcoidosis ("naked" granulomas), lymphoma, or demodicosis (Demodex mites in follicles >5/cm²).

— Standardized skin surface biopsy (cyanoacrylate) or superficial scraping under mineral oil — counts >5 mites/cm² support demodicosis overlap and predict response to topical ivermectin.

— Consider when contact dermatitis is in differential (cosmetics, fragrances, preservatives) and rash is asymmetric or unusual.

— CT/MRI face only for surgical planning of severe rhinophyma or to exclude tumor in nodular asymmetric lesions.

— Abdominal imaging only when systemic flushing syndrome workup is positive.

— Meibography for gland dropout.

— Corneal topography if neovascularization or thinning suspected.

— One diagnostic feature is sufficient: fixed centrofacial erythema with periodic intensification OR phymatous change.

— Otherwise, ≥2 major features required.

— Biopsy showing follicular plugging + interface change + perifollicular lymphocytes → consider lupus, not rosacea.

— Stellate vessels + telangiectasia + ulcer on nose → biopsy to rule out basal cell carcinoma masquerading as rhinophyma — a real Step 3 pitfall in elderly men.

Skin biopsy — reserved for atypical/refractory cases:

Demodex assessment:

Patch testing:

Imaging:

Ophthalmologic specialty testing:

Confirmatory criteria (2017 ROSCO/NRS update):

Differential confirmatory cues:

Genetic/molecular workup: not indicated clinically; research links to HLA-DRA, BTNL2 SNPs.

Board pearl: In an older patient with "rhinophyma" that is asymmetric, ulcerated, or rapidly enlarging, biopsy before laser/surgical resurfacing — basal cell and squamous cell carcinomas hide within phymatous tissue and dermabrasion will seed the field. Always document a pre-procedure skin exam and consider Mohs referral if histology is positive.

Risk Stratification and Treatment Logic

— Daily broad-spectrum sunscreen SPF ≥30, mineral (zinc oxide/titanium dioxide) preferred — chemical sunscreens often sting.

— Gentle skincare: non-soap synthetic cleansers, lukewarm water, fragrance-free moisturizer with ceramides/dimethicone; avoid astringents, alcohol-based toners, scrubs, AHAs, retinoids initially.

— Trigger diary: sun, heat, alcohol (esp. red wine), spicy food, hot beverages, stress, exercise — identify and modify.

— Discontinue offending agents: topical/inhaled steroids on face, niacin, flushing-inducing drugs when feasible.

— Persistent erythema (background redness): topical brimonidine 0.33% gel (α2-agonist) daily or oxymetazoline 1% cream daily — vasoconstrictors, onset 30 min, duration ~12 h. Counsel on rebound erythema risk with brimonidine.

— Flushing (paroxysmal): trigger avoidance ± low-dose β-blocker (carvedilol, propranolol) off-label for refractory cases.

— Telangiectasia: pulsed-dye laser (PDL) or intense pulsed light (IPL) — definitive treatment; topicals don't work.

— Papules/pustules (mild–moderate): topical ivermectin 1% cream daily (first-line, addresses Demodex/inflammation) OR metronidazole 0.75–1% OR azelaic acid 15% gel.

— Papules/pustules (moderate–severe): add oral doxycycline 40 mg modified-release daily (sub-antimicrobial, anti-inflammatory).

— Phymatous (early/inflammatory): oral isotretinoin low-dose (0.3 mg/kg/day).

— Phymatous (fibrotic): electrosurgery, CO₂ laser, dermabrasion, surgical debulking.

— Ocular: lid hygiene (warm compresses, baby shampoo scrubs), artificial tears, oral doxycycline, cyclosporine 0.05% drops for refractory dry eye.

Phenotype-directed therapy (rather than subtype-locked) is the modern approach — treat each feature the patient presents with.

Universal foundational measures (all patients):

Feature-targeted first-line therapy:

Step 3 management: Match the dominant feature to the drug — not the subtype label. A patient bothered most by redness gets brimonidine/oxymetazoline + laser referral; the one with pustules gets ivermectin ± doxycycline. Ordering oral antibiotics for pure erythematotelangiectatic rosacea is a wrong answer.

Pharmacotherapy — First-Line Regimens

— Ivermectin 1% cream once daily — best evidence for papulopustular rosacea; superior to metronidazole at 16 weeks; targets Demodex and inflammation.

— Metronidazole 0.75% (BID) or 1% (daily) gel/cream — long-standing first-line; safe in pregnancy after first trimester (category B).

— Azelaic acid 15% gel BID — anti-inflammatory, normalizes keratinization; can sting/burn initially; safe in pregnancy.

— Brimonidine 0.33% gel daily — α2-agonist for erythema; risk of paradoxical rebound erythema or worsening flushing in 10–20%.

— Oxymetazoline 1% cream daily — α1-agonist; less rebound than brimonidine.

— Sodium sulfacetamide 10%/sulfur 5% — adjunct; avoid in sulfa allergy.

— Topical minocycline 1.5% foam (FDA-approved 2020) — alternative for papulopustular rosacea.

— Doxycycline 40 mg modified-release (30 mg IR + 10 mg DR) daily — sub-antimicrobial dose, anti-inflammatory, no resistance pressure — preferred first-line oral.

— Doxycycline 50–100 mg daily — traditional dose if MR unavailable; counsel on photosensitivity (compounds rosacea trigger!), esophagitis (take upright with water), GI upset.

— Minocycline 50–100 mg daily — alternative; risks: vestibular side effects, drug-induced lupus, hyperpigmentation, DRESS.

— Tetracyclines contraindicated in pregnancy, breastfeeding, children <8.

— Erythromycin or azithromycin — useful in pregnancy or tetracycline intolerance.

— Isotretinoin low-dose 0.25–0.3 mg/kg/day — refractory papulopustular or early phymatous; requires iPLEDGE enrollment, monthly pregnancy tests, lipid/LFT monitoring.

Topical agents (mainstay for mild–moderate disease):

Oral antibiotics (for moderate–severe papulopustular or ocular disease):

Second-line oral:

Duration: Topicals indefinitely; oral antibiotics typically 8–16 weeks, then taper with maintenance topical.

Board pearl: Sub-antimicrobial doxycycline 40 mg MR is the preferred oral for papulopustular rosacea because it provides anti-inflammatory benefit without selecting resistance — a value/stewardship answer Step 3 loves. After clearance, transition to topical ivermectin or metronidazole monotherapy for maintenance to avoid chronic antibiotic exposure.

Procedures and Advanced Therapies

— Pulsed-dye laser (PDL, 585–595 nm) — gold standard; 2–4 sessions every 4–6 weeks; transient purpura common.

— KTP laser (532 nm) — best for discrete fine vessels; less purpura.

— Intense pulsed light (IPL, 500–1200 nm) — broad chromophore targeting, good for diffuse erythema and telangiectasia simultaneously.

— Contraindications: recent tanning, isotretinoin within 6 months (relative — recent data more permissive), active infection, photosensitizing drugs.

— Electrosurgery/electrocautery for shave and contour.

— CO₂ or Er:YAG laser ablation — precise resurfacing of rhinophyma.

— Dermabrasion/cold-steel excision — for bulky disease.

— Cryosurgery — limited role.

— Always biopsy suspicious areas first to exclude BCC/SCC hiding in phyma.

— Lid debridement, meibomian gland expression, thermal pulsation (LipiFlow).

— Cyclosporine 0.05% or lifitegrast 5% drops for refractory dry eye.

— Punctal plugs for severe aqueous deficiency.

— Dermatology for laser, isotretinoin, Morbihan disease.

— Ophthalmology for any corneal involvement.

— Plastic/oculoplastic surgery for advanced rhinophyma or lymphedematous cheek/eyelid distortion.

Vascular laser/light therapy — definitive for telangiectasia and persistent erythema:

Phymatous rosacea procedures:

Botulinum toxin (intradermal microdroplet) — emerging for refractory flushing/erythema; off-label; 3–4 month duration.

Oral isotretinoin — for phyma-prone, treatment-resistant, or relapsing disease; 0.25–0.3 mg/kg/day is preferred over acne dosing; iPLEDGE compliance mandatory.

Ocular procedures and adjuncts:

Refractory disease referrals:

Step 3 management: A 32-year-old whose chief complaint is visible cheek telangiectasias unresponsive to topical metronidazole for 6 months — the next best step is referral for pulsed-dye laser/IPL, not switching topicals or adding oral antibiotics. Telangiectasias do not regress with pharmacotherapy; they require light-based ablation.

Special Populations — Elderly and Renal/Hepatic Impairment

— Higher rates of phymatous rosacea in men; always exclude basal cell carcinoma in nodular or ulcerated rhinophyma — biopsy any atypical lesion before resurfacing.

— Thinner, drier skin — start with the gentlest topicals (azelaic acid often tolerated better than metronidazole gel).

— Polypharmacy review: amlodipine, nitrates, niacin, sildenafil, SSRIs, and tamoxifen all worsen flushing — substitute when clinically feasible.

— Photoaging-related telangiectasias on cheeks can mimic rosacea; treatment overlaps (laser/IPL) but coexisting actinic keratoses and skin cancers must be screened.

— Falls/dizziness risk with topical brimonidine (rare systemic absorption causing hypotension) — avoid in frail elderly with autonomic instability.

— Topicals (metronidazole, ivermectin, azelaic acid, brimonidine, oxymetazoline): minimal systemic absorption — no dose adjustment.

— Doxycycline: hepatically eliminated — preferred tetracycline in renal disease; no adjustment needed even in ESRD.

— Minocycline: reduce dose with severe renal impairment (CrCl <30); accumulation increases vestibular toxicity.

— Isotretinoin: caution; monitor lipids (often worse in CKD).

— Doxycycline: use cautiously — hepatotoxicity rare but reported; avoid with active hepatitis.

— Minocycline: avoid — associated with autoimmune hepatitis and drug-induced lupus.

— Isotretinoin: contraindicated in active liver disease; check LFTs at baseline, 1 month, then every 1–3 months; also baseline lipid panel — hypertriglyceridemia common.

— Erythromycin/azithromycin: CYP3A4 — beware interactions with statins, warfarin, anticoagulants.

— Simplify regimens to once-daily; pictorial instructions.

— Avoid brimonidine if rebound erythema cannot be self-recognized.

Older adults (>65):

Renal impairment:

Hepatic impairment:

Cognitive/adherence considerations:

Board pearl: In an elderly patient on amlodipine with new-onset facial flushing and erythema, before escalating rosacea therapy, review the medication list and discuss switching to an alternative antihypertensive with the prescriber. Vasodilator-induced flushing masquerading as rosacea is a classic Step 3 polypharmacy item — and the "best next step" is medication reconciliation, not adding brimonidine.

Special Populations — Pregnancy, Lactation, and Pediatrics

— Rosacea often worsens in pregnancy from hormonal shifts and vasodilation; pyogenic granuloma-like flares occasionally.

— Safe topicals: azelaic acid (category B), metronidazole (B, generally avoided first trimester), erythromycin topical, sulfacetamide.

— Avoid: brimonidine (limited data), oxymetazoline, topical retinoids, ivermectin (limited human pregnancy data — avoid in first trimester).

— Oral options: erythromycin or azithromycin preferred; avoid all tetracyclines (tooth discoloration, bone deposition after week 15); avoid isotretinoin — category X, mandatory iPLEDGE two-form contraception, monthly pregnancy testing, 1-month post-discontinuation waiting period.

— Counsel: trigger avoidance, mineral sunscreen (chemical absorbers cross placenta — limited evidence of harm but mineral preferred).

— Topicals with minimal systemic absorption acceptable; avoid applying near nipple/breast.

— Doxycycline: short courses (<3 weeks) considered compatible by AAP; longer courses carry theoretical tooth/bone risk to infant — prefer macrolides.

— Isotretinoin contraindicated.

— Primary rosacea in children is rare; consider periorificial (perioral) dermatitis instead — papulopustular eruption sparing vermillion border, often triggered by topical or inhaled steroids.

— Granulomatous periorificial dermatitis affects prepubertal children, especially in skin of color.

— First step: discontinue all topical steroids and minimize inhaled steroid contact (rinse mouth, use spacer).

— Treatment: topical metronidazole, erythromycin, or pimecrolimus; oral erythromycin if extensive; avoid tetracyclines under age 8.

— Ocular rosacea in children presents as recurrent chalazia and keratitis — refer to pediatric ophthalmology; can scar cornea if untreated.

— Distinguish rosacea from acne — no comedones, central distribution, flushing triggers; oral doxycycline allowed after age 8 and after permanent dentition.

Pregnancy:

Lactation:

Pediatric considerations:

Adolescents:

Step 3 management: Pregnant patient with worsening papulopustular rosacea — first-line is topical azelaic acid or metronidazole, escalate to oral erythromycin if needed. The wrong answers will be doxycycline, isotretinoin, or topical ivermectin — recognize the pregnancy-safe stepladder.

Complications and Adverse Outcomes

— Phymatous progression — irreversible fibrotic remodeling, especially rhinophyma; psychosocial morbidity and airway implications in severe cases.

— Persistent telangiectasia — permanent without laser intervention.

— Solid persistent facial edema (Morbihan disease) — chronic lymphedema of forehead, glabella, cheeks, eyelids; treatment-resistant; trial isotretinoin + doxycycline + manual lymphatic drainage.

— Post-inflammatory hyperpigmentation in skin of color after papulopustular flares.

— Steroid-induced rosacea/rebound — chronic topical corticosteroid use produces atrophy, telangiectasia, and rosacea-like flare on withdrawal.

— Chronic blepharoconjunctivitis, recurrent chalazia, hordeola.

— Keratitis — punctate epithelial erosions → marginal infiltrates → peripheral neovascularization → corneal thinning → perforation.

— Episcleritis, scleritis (uncommon).

— Permanent visual loss possible if corneal scarring untreated.

— Brimonidine rebound erythema — paradoxical worsening 3–6 h after application; sometimes severe enough to discontinue.

— Doxycycline: photosensitivity (paradoxical rosacea trigger!), pill esophagitis, candidal vaginitis, intracranial hypertension (rare), C. difficile.

— Minocycline: drug-induced lupus, autoimmune hepatitis, DRESS, vestibular toxicity, blue-gray hyperpigmentation.

— Isotretinoin: teratogenicity, hypertriglyceridemia, LFT elevation, mood changes, mucocutaneous dryness, paradoxical flare in first 4 weeks.

— Laser/IPL: purpura, dyspigmentation (especially Fitzpatrick IV–VI), scarring, burns.

— Significantly elevated rates of depression and anxiety; screen with PHQ-2/GAD-2.

— Workplace and social avoidance, reduced quality of life comparable to psoriasis.

— Modestly increased cardiovascular and metabolic risk markers; migraine; inflammatory bowel disease; possibly Parkinson disease — translate to lifestyle counseling, not screening tests.

Dermatologic complications:

Ocular complications (sight-threatening if missed):

Treatment-related adverse effects:

Psychosocial complications:

Associated systemic risks (emerging data):

Board pearl: A rosacea patient who develops photophobia, blurred vision, or eye pain needs same-day ophthalmology referral — corneal melt and perforation are real outcomes of untreated ocular rosacea, and "follow up at next visit" is a wrong answer.

When to Escalate Care — Referral and Specialist Input

— Failure of 8–12 weeks of first-line topical + oral therapy.

— Phymatous changes considering procedural management.

— Severe persistent erythema or telangiectasia requiring laser/IPL.

— Diagnostic uncertainty (atypical morphology, granulomatous variant, Morbihan disease).

— Need for isotretinoin (iPLEDGE-registered prescriber required).

— Recurrent flares despite adherence.

— Vision change, photophobia, eye pain.

— Corneal infiltrate, ulceration, neovascularization.

— Episcleritis or scleritis.

— Non-urgent referral for symptomatic ocular rosacea unresponsive to lid hygiene + artificial tears + doxycycline.

— Advanced rhinophyma for surgical debulking.

— Periocular Morbihan edema affecting visual axis.

— Suspected carcinoid (5-HIAA elevated) → GI/oncology.

— Suspected pheochromocytoma (elevated metanephrines) → endocrinology + imaging.

— Mastocytosis (elevated tryptase) → hematology.

— Positive PHQ-9 or GAD-7; significant social impairment; body dysmorphic features.

— DRESS or Stevens-Johnson from minocycline/sulfonamides — admit, stop drug, supportive care, consider IV steroids/cyclosporine per severity.

— Severe rosacea fulminans (pyoderma faciale) — abrupt-onset draining nodules in young women — may require systemic corticosteroids + isotretinoin; usually managed outpatient with close dermatology follow-up.

— Corneal perforation from ocular rosacea — ophthalmologic emergency.

— Coordinate isotretinoin labs with primary care to avoid duplication.

— Communicate flushing-inducing drug substitutions (e.g., switching amlodipine to an ARB) back to the prescriber.

Dermatology referral indications:

Ophthalmology referral — urgent same-day if:

Plastic surgery / oculoplastics:

Gastroenterology / endocrinology / hematology:

Mental health:

Hospitalization (rare in rosacea itself):

Transition-of-care considerations:

CCS pearl: For a young woman with sudden onset of confluent painful pustules, nodules, and draining sinuses on the central face without systemic illness — diagnose rosacea fulminans (pyoderma faciale), start prednisone 0.5–1 mg/kg with overlapping isotretinoin initiated after 1–2 weeks, and consult dermatology. Antibiotics alone are insufficient.

Key Differentials — Same-Category (Facial Inflammatory Dermatoses)

— Comedones present (open and closed) — the cardinal distinction.

— Wider distribution including back, chest, shoulders.

— Younger patients; hormonal triggers (menstrual, PCOS).

— Treatment: benzoyl peroxide, topical retinoids, hormonal therapy — agents that worsen rosacea.

— Papulopustules and scaly papules around mouth, nose, eyes; spares vermillion border (key 2–3 mm clear zone).

— Triggered by topical/inhaled corticosteroids, fluoride toothpaste, occlusive cosmetics.

— Treatment: stop steroids, topical metronidazole/pimecrolimus, oral tetracyclines or erythromycin (in children).

— Greasy yellow scale on nasolabial folds, eyebrows, scalp, ears, chest.

— Pruritic rather than burning; responds to ketoconazole and low-potency steroids.

— Can coexist with rosacea ("seborosacea").

— Diffuse facial papulopustules with follicular prominence, often in immunocompromised hosts.

— Skin scrape >5 mites/cm²; treat with topical ivermectin or oral ivermectin.

— Asymmetric, pruritic, well-demarcated; correlates with cosmetic/skincare exposure; patch testing diagnostic.

— Monomorphic pustules; gram-negative folliculitis emerges after prolonged tetracycline use in acne/rosacea — culture and switch to isotretinoin or amoxicillin/TMP-SMX.

— Explosive onset coalescing nodules and sinuses in young women; treat with prednisone + isotretinoin.

— EGFR inhibitors (cetuximab, erlotinib), lithium, corticosteroids, iodides, B12 — monomorphic, sudden onset, no comedones.

Acne vulgaris:

Perioral (periorificial) dermatitis:

Seborrheic dermatitis:

Demodicosis:

Contact dermatitis:

Folliculitis (bacterial, gram-negative, pityrosporum):

Pyoderma faciale / rosacea fulminans:

Acneiform drug eruptions:

Key distinction: Comedones = acne; sparing of vermillion border = perioral dermatitis; greasy scale on nasolabial folds = seb derm; central face + telangiectasia + flushing = rosacea. This four-feature triage solves most Step 3 facial rash questions in seconds. Treatment crosses over (metronidazole works in rosacea and perioral dermatitis; tetracyclines in acne and rosacea), but the diagnosis must come first.

Key Differentials — Other-Category Systemic Mimics

— Malar (butterfly) rash spares nasolabial folds (rosacea involves them).

— Photosensitive; accompanied by arthralgias, oral ulcers, cytopenias, serositis.

— Workup: ANA, anti-dsDNA, anti-Smith, complement, UA.

— Heliotrope rash, Gottron papules, shawl/V-sign; proximal muscle weakness; elevated CK/aldolase.

— Anti-Mi-2, anti-MDA5 (rapidly progressive ILD).

— Episodic flushing + diarrhea + wheezing + right-heart valvular disease (TR/PS).

— Triggers: alcohol, stress, tyramine foods.

— Diagnosis: 24-h urinary 5-HIAA; CT/octreotide scan for tumor.

— Paroxysmal hypertension, palpitations, sweating, headache; flushing actually less common (pallor predominates) — but boards include it.

— Plasma free metanephrines.

— Flushing + urticaria + GI symptoms + syncope; tryptase >20.

— Plethoric face, aquagenic pruritus, splenomegaly, elevated Hgb, JAK2 V617F.

— Hot flashes with sweating, predictable with hormonal context; no fixed erythema or telangiectasia.

— Drug history — niacin, vancomycin (red man), CCBs, nitrates, sildenafil, alcohol with disulfiram or in ALDH2-deficient patients.

— Violaceous indurated plaques on nose, cheeks, ears; biopsy → non-caseating granulomas; CXR for hilar adenopathy.

— Asymmetric, ulcerated, pearly with telangiectasia within phymatous tissue — biopsy mandatory.

— Photo-distributed papules/plaques on sun-exposed sites with seasonal pattern.

Systemic lupus erythematosus (SLE):

Dermatomyositis:

Carcinoid syndrome:

Pheochromocytoma:

Systemic mastocytosis / mast cell activation:

Polycythemia vera:

Menopausal vasomotor flushing:

Niacin or medication flush:

Sarcoidosis (lupus pernio):

Basal cell carcinoma masquerading as rhinophyma:

Polymorphous light eruption / chronic actinic dermatitis:

Board pearl: When facial flushing comes with diarrhea, wheeze, or right-heart murmur, think carcinoid, not rosacea — 24-hour urinary 5-HIAA is the next best test, not topical metronidazole. Systemic features + flushing always warrant looking beyond the skin.

Long-Term Management and Maintenance

— Induction (8–16 weeks): combination topical + oral therapy tailored to dominant phenotype.

— Maintenance (indefinite): lowest-effective regimen, typically once-daily topical (ivermectin or metronidazole) plus sunscreen plus trigger avoidance — drastically reduces relapse rate (NEJM-tier evidence for ivermectin maintenance).

— Continue daily topical agent that achieved remission.

— Discontinue oral antibiotic gradually (e.g., taper doxycycline 40 mg MR to alternate days × 4 weeks, then stop).

— Maintain sunscreen SPF ≥30 mineral daily — UV is the most consistent trigger.

— Re-evaluate for laser referral once erythema/telangiectasia is the residual concern.

— Trigger diary review.

— Alcohol moderation, especially red wine.

— Heat/cold exposure mitigation (scarves, cool drinks).

— Stress reduction — CBT, mindfulness reduces flare frequency.

— Mediterranean dietary pattern (lower in spicy/cinnamaldehyde-rich foods that activate TRPA1) anecdotally helpful; emerging evidence for gut–skin axis.

— Synthetic detergent cleanser, ceramide moisturizer, mineral sunscreen — the "three-product rule" for rosacea-prone skin.

— Reintroduce active ingredients (low-strength niacinamide, azelaic acid) cautiously once stable.

— Daily warm compress + lid scrubs.

— Omega-3 supplementation 2 g/day — modest benefit for meibomian gland dysfunction.

— Artificial tears as needed.

— Avoid chronic full-dose tetracyclines; use sub-antimicrobial doxycycline 40 mg MR if oral therapy needed long-term.

— Document microbiome rationale in the chart.

Treatment paradigm: induction → maintenance:

Discharge / chronic care plan after acute flare control:

Lifestyle anchors (every visit):

Skincare maintenance:

Ocular maintenance:

Antibiotic stewardship:

Step 3 management: After clearing papulopustular rosacea with doxycycline 40 mg MR + topical ivermectin × 12 weeks, the next best step is to discontinue doxycycline and continue daily topical ivermectin as maintenance, not continue antibiotics indefinitely. Long-term antibiotic continuation is a wrong answer; topical maintenance is the right one.

Follow-Up, Monitoring, and Counseling

— Initial: 6–8 weeks after starting therapy to assess response and tolerability.

— Stable: every 3–6 months in the first year, then annually with PCP if maintained on topical monotherapy.

— Isotretinoin patients: monthly visits for iPLEDGE — pregnancy test (women of reproductive potential), lipid panel, LFTs, depression screening.

— Long-term tetracycline (>3 months): check LFTs every 3–6 months for minocycline; doxycycline rarely requires labs but assess GI/photosensitivity at each visit.

— Investigator Global Assessment (IGA) — clear, almost clear, mild, moderate, severe.

— Clinician Erythema Assessment (CEA) for redness.

— Lesion counts (papules + pustules).

— Patient-Reported Outcome (PRO) — RosaQoL score.

— Standardized photography under consistent lighting.

— Annual eye exam for known rosacea patients; sooner if symptomatic.

— Schirmer/tear breakup if dry eye reported.

— Set expectations: rosacea is chronic and relapsing, not curable — sustained remission is realistic.

— Adherence improves with simplified once-daily regimens — emphasize topical ivermectin or metronidazole maintenance.

— Sunscreen daily is the single highest-yield behavior.

— Avoid abrasive cosmetics, alcohol-based toners, fragranced products.

— Photosensitivity warning for tetracyclines — counteract by double-down on sunscreen.

— Mental health: normalize psychosocial impact; refer if PHQ-9 ≥10.

— Per USPSTF: BP at each visit, lipid screening per ASCVD risk calculator, diabetes screening per age/BMI — rosacea patients carry modestly elevated metabolic risk markers and benefit from primary prevention attention.

— Generic topical metronidazole is inexpensive; ivermectin and oxymetazoline cost more — prior auth often needed.

— Laser/IPL are typically not covered (cosmetic) — counsel on out-of-pocket cost before referral.

Follow-up cadence:

Outcome measures to track:

Ocular monitoring:

Counseling priorities:

Cardiometabolic comorbidity screening:

Insurance/value considerations:

Board pearl: Counsel every tetracycline-treated patient about photosensitivity AND esophagitis — take with full glass of water, remain upright 30 minutes, and use sunscreen — failure to counsel is a documentation/patient-safety wrong answer on Step 3 communication items.

Ethical, Legal, and Patient Safety Considerations

— Document teratogenicity counseling, two forms of contraception for 1 month before, during, and 1 month after therapy.

— Monthly pregnancy testing and registry attestation; failure to enroll constitutes regulatory violation.

— Discuss mood/depression risks — screen with PHQ-9 each visit; document patient acknowledgment.

— Discuss inflammatory bowel disease association (controversial but disclose).

— Risks: dyspigmentation (especially Fitzpatrick IV–VI), scarring, burns, transient purpura, need for multiple sessions, cosmetic (often not insured).

— Document realistic outcome expectations and that telangiectasias may recur.

— Document warning against chronic facial corticosteroid use; provide written instructions; offer pimecrolimus/tacrolimus as steroid-sparing alternatives for inflammatory dermatoses near the face.

— Steroid-induced rosacea is a preventable iatrogenic harm — a recurring patient safety theme.

— Document rationale for sub-antimicrobial dosing to minimize resistance and microbiome disruption.

— Avoid prolonged full-dose tetracyclines for cosmetic-only flares.

— When patient moves between PCP and dermatology, ensure medication reconciliation — duplicate antibiotic prescriptions and missed iPLEDGE lab orders are documented Step 3 safety pitfalls.

— Communicate substitutions (e.g., amlodipine → ARB) clearly back to the originating prescriber to avoid "ping-pong" re-prescribing.

— Erythema is harder to detect on Fitzpatrick IV–VI — rely on warmth, burning, telangiectasia patterns, and patient-reported flushing. Underdiagnosis is a recognized disparity.

— Counsel about hyperpigmentation risk with laser and post-inflammatory marks.

— Screen for depression/anxiety; refer for CBT — untreated mental health comorbidity is an ethical lapse, not optional.

— Cooks, welders, foundry workers, and outdoor laborers face exacerbating exposures; document occupational counseling and consider workplace accommodation letters.

Informed consent — isotretinoin and iPLEDGE:

Informed consent — laser/IPL:

Topical steroid stewardship:

Antibiotic stewardship and value-based care:

Transition-of-care risks:

Cultural humility and skin of color:

Mental health and body image:

Mandatory reporting / occupational:

Step 3 management: A 28-year-old woman started on isotretinoin for refractory rosacea calls reporting a missed period — the best next step is to stop isotretinoin immediately, order a urine + quantitative serum β-hCG, and report through iPLEDGE. Continuing the drug or waiting until the next monthly visit is both unethical and a regulatory violation.

High-Yield Associations and Rapid-Fire Clinical Facts

No comedones — distinguishes rosacea from acne.

Spares periocular and perioral skin — distinguishes from seb derm and perioral dermatitis.

Malar rash sparing nasolabial folds — SLE, not rosacea.

Triggers mnemonic "HEAT SCARS": Hot drinks, Exercise, Alcohol, Temperature extremes, Sun, Cosmetics/Corticosteroids, Anger/stress, Red wine, Spicy food.

First-line topical for papulopustular rosacea — ivermectin 1% (best evidence) or metronidazole.

First-line oral — doxycycline 40 mg modified-release daily (sub-antimicrobial).

Erythema-targeted topicals — brimonidine (rebound risk) or oxymetazoline.

Telangiectasia treatment — pulsed-dye laser or IPL (no topical works).

Rhinophyma treatment — surgical/CO₂ laser ablation; biopsy first to exclude BCC.

Ocular rosacea first-line — lid hygiene + warm compresses + artificial tears + oral doxycycline; ophthalmology if corneal involvement.

Demodex association — explains ivermectin efficacy; consider in immunocompromised hosts.

Steroid-induced rosacea — stop the steroid; bridge with pimecrolimus or tetracycline; expect rebound.

Pregnancy-safe — azelaic acid, metronidazole, erythromycin (oral); avoid tetracyclines and isotretinoin.

Rosacea fulminans (pyoderma faciale) — explosive central face nodules in young women; prednisone + isotretinoin.

Morbihan disease — chronic solid facial edema; refractory; trial isotretinoin + doxycycline + lymphatic drainage.

iPLEDGE — mandatory for isotretinoin; two forms of contraception, monthly pregnancy testing.

Drug-induced lupus — minocycline classic offender; ANA + anti-histone antibodies.

Carcinoid red flags — flushing + diarrhea + wheezing + right-heart murmur → 24-h urinary 5-HIAA.

Pheochromocytoma red flags — paroxysmal HTN + palpitations + headache + sweating → plasma metanephrines.

Comorbidities — depression, anxiety, migraine, IBD, modestly increased CV risk.

Sunscreen — daily mineral SPF ≥30 is the single highest-yield long-term intervention.

Board pearl: When in doubt on a facial rash question, search the stem for (1) comedones, (2) vermillion sparing, (3) greasy scale, (4) systemic flushing triggers — these four anchors solve 90% of Step 3 facial dermatosis vignettes in under 20 seconds.

Board Question Stem Patterns

— 38-year-old woman, central facial erythema, papules and pustules on cheeks, no comedones, triggered by red wine. → Topical ivermectin or metronidazole, NOT benzoyl peroxide or topical retinoid.

— Persistent visible cheek vessels after 6 months of topical metronidazole. → Refer for pulsed-dye laser/IPL, not switch antibiotics.

— Facial flushing + recurrent chalazia + gritty eyes. → Lid hygiene + warm compresses + oral doxycycline; ophthalmology if vision changes.

— Patient applies hydrocortisone/clobetasol cream to face for "eczema" for months → worsening papules and telangiectasia. → Stop the steroid; bridge with pimecrolimus or topical metronidazole; expect rebound flare.

— Older man with asymmetric ulcerated nodule within rhinophyma. → Biopsy before laser/surgery — rule out BCC/SCC.

— Flushing + diarrhea + wheezing + right-heart murmur. → 24-hour urinary 5-HIAA (carcinoid), not topical brimonidine.

— Pregnant woman with worsening papulopustular rosacea. → Topical azelaic acid or metronidazole; oral erythromycin if needed; avoid doxycycline and isotretinoin.

— Elderly man with new facial flushing on amlodipine. → Switch antihypertensive (e.g., to ARB) before adding rosacea therapy.

— Patient using brimonidine reports worsening redness 4 hours after application. → Discontinue brimonidine; trial oxymetazoline or address underlying inflammation.

— Young woman, abrupt-onset confluent nodules and pustules without systemic illness. → Prednisone + initiate isotretinoin after 1–2 weeks; dermatology referral.

— Patient cleared on doxycycline + topical ivermectin × 12 weeks. → Discontinue doxycycline, continue topical ivermectin as maintenance — not lifelong antibiotic.

— Isotretinoin patient missed period. → Stop drug, β-hCG, iPLEDGE report.

Pattern 1 — Rosacea vs acne:

Pattern 2 — Telangiectasia management:

Pattern 3 — Ocular rosacea recognition:

Pattern 4 — Steroid-induced rosacea:

Pattern 5 — Rhinophyma + occult malignancy:

Pattern 6 — Flushing mimic:

Pattern 7 — Pregnancy:

Pattern 8 — Drug substitution:

Pattern 9 — Brimonidine rebound:

Pattern 10 — Rosacea fulminans:

Pattern 11 — Antibiotic stewardship:

Pattern 12 — iPLEDGE event:

Board pearl: Step 3 rewards the next best management step, not the diagnosis alone — anchor your answer to the dominant phenotype (erythema vs pustules vs telangiectasia vs phyma vs ocular) and the safety/stewardship layer.

One-Line Recap

Rosacea is a chronic relapsing centrofacial inflammatory dermatosis managed by phenotype-directed therapy — daily sunscreen and trigger avoidance for everyone, topical ivermectin or metronidazole for papulopustules, sub-antimicrobial doxycycline 40 mg MR for moderate–severe inflammation, brimonidine/oxymetazoline or pulsed-dye laser for erythema and telangiectasia, isotretinoin or surgical/CO₂ laser ablation for phymatous disease, and lid hygiene plus doxycycline plus prompt ophthalmology referral for ocular involvement.

Diagnostic anchor: Centrofacial erythema + flushing triggers + telangiectasia + papulopustules without comedones; biopsy/labs only for atypical or systemic mimics (lupus, carcinoid, pheo, sarcoid).

Phenotype-to-drug map: Redness → brimonidine/oxymetazoline ± laser; pustules → ivermectin/metronidazole/azelaic acid ± sub-antimicrobial doxycycline; vessels → PDL/IPL; phyma → isotretinoin or ablative surgery; eye → lid hygiene + doxycycline + ophthalmology.

Special-population fast facts: Pregnancy — azelaic acid, metronidazole, oral erythromycin; pediatric "rosacea" is usually periorificial dermatitis (stop steroids, topical metronidazole); elderly rhinophyma — biopsy before resurfacing to exclude BCC.

Safety/stewardship layer: Stop facial corticosteroids; counsel on doxycycline photosensitivity and esophagitis; use sub-antimicrobial dosing; iPLEDGE for isotretinoin; screen for depression and ocular involvement; daily SPF ≥30 mineral sunscreen is the single highest-yield long-term intervention; refer same-day to ophthalmology for any vision change, pain, or corneal sign.