What is the diagnosis and treatment for a chronic, raised facial rash on both cheeks, without blisters or vesicles, that has persisted for 1 year?

Chronic Bilateral Malar Rash Without Vesicles: Diagnosis and Management

The most likely diagnosis is rosacea (erythematotelangiectatic or papulopustular subtype), and first-line treatment should be topical metronidazole or azelaic acid applied once to twice daily, combined with trigger avoidance and photoprotection. 1, 2

Differential Diagnosis

The clinical presentation of a chronic, raised facial rash on both cheeks without blisters or vesicles, persisting for 1 year, most strongly suggests:

Primary Consideration: Rosacea

• Rosacea characteristically affects the central face (cheeks, nose, chin, forehead) with persistent erythema, telangiectasia, and inflammatory papules without vesicles 1, 2
• The bilateral malar distribution and chronicity (1 year) are classic for rosacea, which is a chronic progressive condition of flare-ups and remissions 3
• Peak onset occurs in the 40s-50s, affecting up to 10% of the population, more common in fair-skinned individuals 4
• The raised nature without vesicles distinguishes this from vesicular conditions 1

Alternative Considerations to Rule Out:

• Atopic eczema: Would typically present with itchiness in skin creases, general dry skin, and often has onset in early childhood rather than chronic adult presentation 5
• Contact dermatitis: Would require exposure history to specific allergens or irritants, and patch testing would be indicated if suspected 5
• Seborrheic dermatitis: Usually involves scaling and affects seborrheic areas including nasolabial folds and eyebrows 6

Diagnostic Approach

Key clinical features to document:

• Presence of persistent erythema (essential component of rosacea) 4, 2
• History of flushing episodes lasting less than 5 minutes, possibly spreading to neck and chest 1
• Presence of telangiectasia (dilated blood vessels) 1, 2
• Inflammatory papules or papulopustules without comedones (distinguishes from acne) 1, 3
• Triggers: alcohol, stress, spicy foods, temperature extremes 7
• Ocular symptoms: burning, grittiness, blepharitis (present in many rosacea patients) 1, 7

Critical pitfall: Rosacea resembles acne vulgaris but lacks comedones and has a different age distribution and central facial pattern 3

First-Line Treatment Algorithm

Step 1: Topical Therapy

For mild to moderate papulopustular rosacea with inflammatory lesions:

• Topical metronidazole 0.75-1% gel or cream applied once to twice daily 1, 2
• OR topical azelaic acid 15-20% applied twice daily 1, 2
• Both agents have comparable efficacy and are recommended as initial treatments by the German Dermatological Society 2

For persistent erythema (if this is the predominant feature):

• Topical brimonidine 0.33% gel once daily (alpha-adrenergic receptor agonist effective in reducing erythema) 1, 2
• OR topical oxymetazoline (alternative vasoconstrictor) 4, 2

Step 2: Essential Adjunctive Measures (All Patients)

• Trigger avoidance: Identify and avoid personal triggers including alcohol, spicy foods, hot beverages, temperature extremes 1, 7
• Gentle skin care: Use mild cleansing agents, avoid harsh soaps and alcohol-containing products 1
• Photoprotection: Wide-brimmed hats and broad-spectrum sunscreen (minimum SPF 30) 1
• Moisturizing regimen: Regular emollient use to support skin barrier 1

Step 3: Systemic Therapy (If Topical Therapy Fails After 8-12 Weeks)

For moderate to severe or therapy-resistant papulopustular rosacea:

• Low-dose doxycycline 40 mg once daily (subantimicrobial dose, drug of choice for systemic therapy) 1, 2
• This formulation provides anti-inflammatory effects without antimicrobial resistance concerns 1
• Alternative: Standard-dose tetracycline if low-dose doxycycline unavailable 7

Step 4: Alternative Systemic Option

For severe or refractory cases:

• Low-dose isotretinoin can be considered as an alternative systemic agent 2
• Requires dermatology consultation and monitoring 2

Special Considerations

If Ocular Symptoms Present:

• Lid hygiene measures 1, 2
• Topical cyclosporine eye drops 1
• Topical or systemic antibiotics (azithromycin, metronidazole, or ivermectin) 2
• Consider ophthalmology referral for persistent ocular involvement 1

If Telangiectasia Predominates:

• Laser or light-based therapies (intense pulsed light or pulsed dye laser) are most effective for erythematotelangiectatic type 4
• Requires dermatology referral for procedural intervention 1

Critical Pitfalls to Avoid

Do not confuse with drug-induced rash: The evidence provided discusses papulopustular eruptions from EGFR inhibitors and MEK inhibitors in cancer patients, which develop within days to weeks of starting therapy and affect 75-90% of patients 5. This is irrelevant unless the patient is on anticancer therapy.

Do not assume bacterial infection without evidence: While bacterial colonization can occur in rosacea, routine bacterial cultures are not indicated unless there is crusting, weeping, yellow discharge, or failure to respond to standard therapy 5

Patient education is essential: Emphasize the chronic nature of rosacea with flare-ups and remissions, and the need for ongoing maintenance therapy even during remission periods 6, 3