What type of dermatitis is associated with lip licking?

Lip-Licking Dermatitis: Diagnosis and Management

Lip-licking dermatitis is a form of irritant contact dermatitis caused by the repetitive habit of licking the lips, which damages the skin barrier and leads to inflammation around the mouth. 1

Clinical Presentation

• Dry, cracked lips with erythema and scaling extending beyond the vermilion border
• Well-demarcated border around the perioral area corresponding to where saliva contacts the skin
• Symptoms include discomfort, burning, and itching
• Chronic cases may show lichenification, cracks, and fissures

Pathophysiology

Lip-licking dermatitis occurs through a cyclical process:

1. Initial lip dryness triggers licking behavior
2. Saliva temporarily moistens lips but quickly evaporates
3. Enzymes in saliva (amylase, lipase) break down skin barrier
4. Evaporation causes further dryness
5. Repeated licking creates an irritant contact dermatitis 1, 2

Treatment Approach

First-Line Treatment

• Apply bland, fragrance-free lip balm with UV protection multiple times daily, especially before bed 1
• 1% hydrocortisone cream/ointment applied 3-4 times daily to affected areas 3
• Gentle cleansing with mild, fragrance-free cleansers
• Avoid potential irritants including flavored lip products, spicy foods, and citrus

For Moderate to Severe Cases

• Medium-potency topical corticosteroids for short courses (5-7 days) 3
• Evaluate for secondary bacterial or fungal infection if not improving
• Tacrolimus 0.1% ointment for lichenified or chronic cases 3

For Extensive or Severe Cases

• If the dermatitis involves >20% of skin area, systemic steroids may be required 2
• Oral prednisone should be tapered over 2-3 weeks to prevent rebound dermatitis 2

Prevention Strategies

• Maintain adequate hydration
• Apply barrier emollients before potential exposures to irritants 3
• Use fragrance-free, dye-free moisturizers in tubes 3
• Protect lips from harsh weather conditions with physical barriers 1
• Break the habit of lip licking through conscious awareness and behavioral modification

Differential Diagnosis

• Allergic contact dermatitis (from lip products)
• Atopic dermatitis with perioral involvement 4
• Angular cheilitis
• Perioral dermatitis
• Exfoliative cheilitis

When to Refer

• Failure to respond to appropriate first-line treatment
• Recurrent episodes despite preventive measures
• Uncertainty about diagnosis
• Suspicion of allergic component requiring patch testing 3

Common Pitfalls

• Mistaking lip-licking dermatitis for other conditions like perioral dermatitis or seborrheic dermatitis
• Using flavored lip balms that may encourage further licking
• Failing to address the underlying behavioral component
• Using topical antihistamines which can cause contact sensitization 3
• Discontinuing topical steroids too quickly, leading to rebound inflammation

Lip-licking dermatitis is a common but often overlooked condition that can significantly impact quality of life. Breaking the cycle of lip licking while restoring the skin barrier is essential for successful management.