Actinic Cheilitis

Definition

• Chronic sun-induced lip damage, primarily affecting the lower lip

• Considered a form of actinic keratosis on the lip, with potential association to actinic prurigo (rare)

• Common in fair-skinned individuals, especially in tropical/subtropical climates where UV exposure is high

• Three times more common in males, particularly those with significant outdoor occupational exposure (e.g. farmers, construction workers)

Aetiology & Risk Factors

• Chronic UV exposure is the main cause; cumulative sun damage over time leads to cellular dysplasia in the lip epithelium

• The lower lip is at higher risk because:

  • It typically has thinner mucosal epithelium

  • It often receives more direct sun exposure than the upper lip

• Additional risk factors:

  • Smoking: Increases carcinogenic potential

  • Alcohol use: Synergistic effect with UV and smoking

  • Immunosuppression (e.g. organ transplant recipients, long-term corticosteroid use)

Clinical Features

1. Early Signs

   • Dryness

   • Thinning of the lip epithelium

   • Fragility, with easy cracking or scaling

2. Later Signs

   • Thickened, scaly papules and plaques

   • Erythema, fissuring

   • Leukokeratosis (white patchy changes)

   • Crusting or ulceration in advanced cases

3. Complications

   • Actinic cheilitis is pre-malignant, with a risk of progression to squamous cell carcinoma (SCC) of the lip if untreated.

   • Risk factors for malignant transformation include smoking, alcohol misuse, high sun exposure, and immunosuppression.

Diagnosis

• Usually a clinical diagnosis based on the characteristic appearance of chronically sun-damaged lower lip.

• Biopsy is indicated if:

  • Lesions persist despite appropriate treatment

  • There is suspicion of SCC (e.g. ulceration, induration, rapid growth, or non-healing areas)

Management

Management aims to prevent progression to SCC and improve patient comfort. A combination of preventive measures, topical treatments, and procedural therapies may be used depending on severity.

1. Lifestyle & Preventive Measures

   • Smoking cessation: Reduces carcinogenic risk.

   • Daily sun protection:

     • Use lip balms with SPF 30+ (reapply every 2 hours and after eating/drinking).

     • Wear wide-brimmed hats that shade the lips.

     • Limit direct sun exposure, especially during peak UV times (10 a.m. – 4 p.m.).

2. Topical Therapies (mild to moderate actinic cheilitis)

   • 5-Fluorouracil (5-FU) cream:

     • Common first-line topical agent for actinic keratoses and actinic cheilitis.

     • Can cause local irritation and erythema; advise patients about expected reaction.

   • Imiquimod cream:

     • Immune response modifier; used for actinic keratoses, basal cell carcinoma in situ, and actinic cheilitis.

     • Can be irritating; treatment schedules vary.

   • Topical retinoids (e.g. tretinoin):

     • May help reverse some dysplastic changes and reduce hyperkeratosis.

   • Photodynamic therapy (PDT):

     • Particularly useful for widespread field changes; involves application of a photosensitiser followed by exposure to a specific light source.

3. Physical Therapies (for severe or refractory cases)

   • Cryotherapy:

     • Liquid nitrogen application; effective for focal thickened lesions.

     • Can be repeated if necessary.

   • Electrocautery:

     • Burns off hyperkeratotic lesions but can be uncomfortable and requires local anaesthesia.

4. Surgical Options

   • Laser ablation:

     • Er:YAG or CO2 laser can remove dysplastic tissue; useful for broad areas.

   • Vermilionectomy (lip shave procedure):

     • Surgical removal of the superficial lip layer (vermilion border); reserved for advanced disease, extensive lesions, or suspected malignant transformation.

     • Allows pathological assessment of excised tissue.

Prognosis & Prevention

• Good prognosis if detected and treated early. Complete resolution of dysplastic areas is possible, especially with topical therapies and strict sun protection.

• Ongoing UV protection is crucial to prevent recurrence and reduce the risk of progression to SCC.

• Regular follow-up is important in cases of severe or recurrent actinic cheilitis, particularly in immunocompromised patients.