Understanding Dark Spots at Lip Corners: Causes & Solutions

Dark spots at the oral commissures (corners of the mouth) have several causes:

1. Post‑inflammatory hyperpigmentation (PIH): After angular cheilitis, eczema, licking dermatitis.
2. Melasma: Hormonal (pregnancy, OCP), sun exposure; symmetric.
3. Chronic irritation: Ill‑fitting dentures, habitual lip licking, wind/cold exposure.
4. Fungal/bacterial overgrowth: Candida/Staph → angular cheilitis → pigmentation.
5. Nutritional deficiencies: Iron, zinc, B₂ (riboflavin), B₆, B₁₂.
6. Medication side effects: Chemo, minocycline, antimalarials.
7. Malignancy (rare): Melanoma, squamous cell carcinoma—if changing, ulcerated, bleeding.

Management

• Treat underlying cause (antifungal/antibiotic for cheilitis, replace dentures, correct deficiencies).
• Topical lightening agents: hydroquinone 2–4%, azelaic acid, niacinamide, kojic acid (lip‑safe formulations).
• Sun protection: Lip balm SPF 30+.
• Dermatology referral if uncertain, refractory, or suspicious for malignancy.