Rosacea — USMLE Step 2 CK Guide 2026

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This is a clinician-written, evidence-based summary aligned to the USMLE Step 2 CK Content Outline. It is intended for medical students preparing for USMLE Step 2 CK. Management reflects current ACC/AHA, USPSTF, and APA guidelines. Always cross-reference with UpToDate, institutional protocols, and clinical judgment.

Key points

Rosacea causes centrofacial flushing, persistent erythema, telangiectasias, and inflammatory papules/pustules
Comedones are absent; their presence suggests acne vulgaris
Triggers: heat, sunlight, alcohol, spicy foods, hot drinks, exercise, emotional stress, topical steroids
Papulopustular rosacea: topical metronidazole, azelaic acid, ivermectin; oral doxycycline for moderate-severe disease
Ocular rosacea can threaten vision; eye pain, photophobia, or visual change needs ophthalmology

Overview

Rosacea is a chronic inflammatory facial dermatosis involving neurovascular dysregulation, innate immune activation, and sometimes Demodex-associated inflammation. Modern classification emphasizes phenotypes: persistent centrofacial erythema, phymatous changes, papules/pustules, flushing, telangiectasias, and ocular features. It is not acne, although papulopustular rosacea is commonly mistaken for acne. Topical corticosteroids can worsen or induce rosacea-like dermatitis.

Epidemiology

Rosacea is most common in adults aged 30-60 and is often recognized in fair-skinned patients, although it occurs in all skin types and may be underdiagnosed in darker skin. Risk factors include family history, sun exposure, heat sensitivity, and triggers that provoke flushing. Phymatous rosacea, especially rhinophyma, is more common in men. Ocular rosacea may precede, accompany, or follow skin disease.

Clinical Features

Symptoms

Recurrent facial flushing and burning/stinging sensitivity

Acne-like bumps on cheeks, nose, chin, or forehead without blackheads/whiteheads

Gritty, dry, red, irritated eyes or recurrent styes

Eye pain, photophobia, corneal symptoms, or vision change

Flares after alcohol, spicy foods, hot beverages, heat, sun, or stress

Signs

Persistent centrofacial erythema with telangiectasias

Papules and pustules on central face with no comedones

Phymatous thickening, classically rhinophyma of nose

Blepharitis, conjunctival injection, meibomian gland dysfunction

Perioral papules sparing vermilion border may suggest perioral dermatitis instead

Investigations

First-line

Clinical diagnosisBased on persistent centrofacial erythema, flushing, telangiectasia, papules/pustules without comedones, phymatous or ocular features

Trigger and medication reviewAsk about topical steroids, alcohol, heat, sun, spicy food, hot drinks, irritating skincare, and photosensitizing drugs

Second-line

Rule out mimicsAcne vulgaris (comedones), lupus (photosensitive malar rash with systemic signs), seborrheic dermatitis, perioral dermatitis, carcinoid flushing if systemic symptoms

Ocular evaluationAssess eye symptoms; refer for moderate-severe ocular signs or any vision-threatening symptoms

Specialist

Biopsy or labsRarely needed; consider ANA/systemic workup if lupus or dermatomyositis features are present

Management

American Acne & Rosacea Society and AAD dermatology care principles

General measures

Identify and avoid personal triggers; daily broad-spectrum sunscreen and gentle skincare
Avoid topical corticosteroids on face unless specifically indicated for another diagnosis
Green-tinted cosmetics and vascular laser/light therapies can reduce visible erythema/telangiectasias

Papulopustular rosacea

Topical metronidazole, azelaic acid, or ivermectin are first-line options
Oral doxycycline, often subantimicrobial anti-inflammatory dosing, for moderate-severe inflammatory disease
Avoid chronic high-dose antibiotics when topical/maintenance options can control disease

Erythematotelangiectatic disease

Topical brimonidine or oxymetazoline can temporarily reduce persistent erythema through vasoconstriction
Laser or intense pulsed light for telangiectasias and persistent erythema when available

Ocular and phymatous rosacea

Ocular: lid hygiene, artificial tears, oral doxycycline when needed, ophthalmology for keratitis or visual symptoms
Rhinophyma/phymatous disease: dermatology; procedural reshaping with laser, electrosurgery, dermabrasion, or surgery may be needed

Complications

Ocular disease: Blepharitis, conjunctivitis, keratitis, corneal ulceration, vision loss
Rhinophyma: Disfiguring nasal sebaceous overgrowth
Steroid-induced rosacea: Rebound flares and periorificial dermatitis after facial steroid use
Psychosocial burden: Embarrassment, reduced quality of life, social avoidance
Misdiagnosis: Acne therapies alone may miss triggers and vascular/ocular components

USMLE Step 2 CK Exam Tips

1Rosacea = central face flushing + telangiectasias + papules/pustules with NO comedones
2Acne has comedones; rosacea does not
3Alcohol/spicy food/heat triggers point toward rosacea
4First-line papulopustular treatment: topical metronidazole, azelaic acid, or ivermectin
5Moderate-severe rosacea: oral doxycycline
6Eye symptoms in rosacea are not benign; ocular rosacea can threaten vision
7Rhinophyma is phymatous rosacea and is classically nasal enlargement in men

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