Soreness at the Corners of the Mouth: Angular Cheilitis & Other Causes

Soreness, cracking, or inflammation at the oral commissures (angles of the mouth) is most often angular cheilitis (perlèche), but several conditions can mimic it.

Differential Diagnosis

Condition	Key Features	Typical Triggers
Angular cheilitis	Bilateral fissures, erythema, maceration	Saliva pooling, denture loss of vertical dimension, B2/B12/Fe deficiency, Candida/Staph
Herpes labialis (HSV‑1)	Vesicles → crusts; prodrome tingling; unilateral	Stress, UV, illness, immunosuppression
Aphthous ulcer	Round ulcer with yellow floor, red halo; non‑keratinized mucosa	Trauma, stress, food sensitivity, deficiencies
Contact dermatitis	Itchy, eczematous; lip balm, toothpaste (SLS), food allergens	Allergens/irritants
Seborrheic dermatitis	Greasy scales on erythema; nasolabial folds, eyebrows	Malassezia, stress
Nutritional deficiency	Glossitis, cheilitis; B2, B3, B6, B12, Fe, Zn	Malabsorption, poor diet, alcohol
Drug‑induced	Isotretinoin (dryness), diuretics, chemo	Medication side effect

Management

1. Topical antifungal + mild steroid (clotrimazole 1% + hydrocortisone 1% BID × 2 wk) for angular cheilitis.
2. Address predisposing factors: replace ill‑fitting dentures, correct deficiencies, treat infections.
3. Barrier: petrolatum or zinc oxide ointment.
4. HSV: oral valacyclovir 2 g BID × 1 day (episodic) or daily suppression.
5. Aphthae: topical corticosteroid (triamcinolone paste), sucralfate slurry.

When to Refer

• Persistent >2 weeks despite treatment
• Unilateral, indurated, ulcerated lesion (rule out SCC)
• Immunocompromised patient
• Systemic symptoms