Solar cheilitis

What is solar cheilitis?

Solar cheilitis is a term used to describe benign or pre-malignant changes on the lip due to chronic sun exposure. It is also often called actinic cheilitis, and sometimes, actinic cheilitis with histological atypia.

The word cheilitis means an inflammatory condition of the lips. Solar cheilitis affects the vermilion, i.e. the red part of the lip.

What are the symptoms of solar cheilitis?

Solar cheilitis most commonly results in the following features:

• Dry lips
• Thinned skin of the lips
• Scaly patches

Less common features of solar cheilitis include:

• Swelling of the lip
• Redness and soreness
• Ulceration and crusting
• Loss of demarcation between the vermilion border of the lip and its adjacent skin
• Prominent folds and lip lines
• White thickened patches (leukokeratosis)
• Discoloured skin with pale or yellow areas

Well-defined scaly areas on the lips in solar cheilitis may be solar keratoses or Bowen disease (squamous cell carcinoma in situ).

Invasive squamous cell carcinoma should be suspected if a persistent ulcer or lump develops.

Actinic cheilitis

What is the cause of solar cheilitis?

Solar cheilitis is due to damage to cellular DNA by chronic sun exposure. Smoking may contribute; cheilitis tends to be more severe in smokers.

Investigations

In most cases, no specific investigations are required in solar cheilitis. A skin biopsy may be taken if skin cancer or an inflammatory skin disease is suspected.

The pathologist may report premalignant changes in the cells of the epidermis (outer layer of the skin) and sun-related changes such as elastosis in the underlying dermis (connective tissue layer).

Management

Treatment options include:

• Cryotherapy
• 5-fluorouracil cream
• Imiquimod cream
• Topical retinoids
• Photodynamic therapy

Limiting sun exposure, wearing a hat with a good brim, and using a lip balm containg sunscreen are recommended. Men can consider growing a moustache. Smoking should be stopped.