Actinic cheilitis: when is dryness of the lower lip sun damage?

Actinic cheilitis is the lip's counterpart of actinic keratosis (a scaly patch caused by the sun) seen on the skin. DermNet defines it as the change long-term sunlight causes on the lip, and attributes it to the lower lip being exposed to ultraviolet (UV) light over many years. The lip is more vulnerable than the skin around it: the layer covering the red part of the lip is thinner and less pigmented, which means its natural protection against the sun is weak. Because the lower lip both sticks out and catches the sun at a steeper angle, it is the side affected in most cases; DermNet gives this proportion as 90%.

Who it is more common in is clear. DermNet lists adults with fair skin, those living in tropical or sunny regions and those who work outdoors, and writes that the condition is three times more common in men than in women. Cleveland Clinic adds to this list people over 65, those living near the equator or at high altitude, and those with skin pigmentation disorders. Farmers, fishermen, construction and road workers, and people who have done outdoor sport for years are the groups who come across this picture more often.

The appearance is insidious, because it forms slowly over the years and the person takes it for the normal state of their own lip. In a systematic review bringing together 728 patients from 13 studies, the commonest findings were dryness (99%), blurring of the line between the red part of the lip and the skin (82%), scaling (69%) and thinning of the tissue (69%). DermNet adds swelling, redness, burning, cracks, crusts, white thickened areas and more prominent lip lines. Cleveland Clinic also writes that some people describe burning, numbness and tenderness in the lip.

The most useful clue that tells actinic cheilitis apart from ordinary dry lips is the border line and how long it has lasted. On a healthy lip there is a sharp border, as if drawn, between the red part and the skin; with actinic cheilitis this border fades, and the red part looks as though it is blending into the skin. Dryness due to winter wind or lip licking, on the other hand, improves with a moisturiser within weeks. The American Academy of Dermatology (AAD) recommends seeing a dermatologist if your lips have not improved within 2–3 weeks despite your own care, and lists actinic cheilitis among the precancerous conditions that should come to mind in this situation.

The answer to why it is regarded as precancerous lies inside the tissue. DermNet writes that actinic cheilitis is a condition that prepares the ground for lip cancer, that is, squamous cell carcinoma. Cleveland Clinic gives the rate of progression as 6 to 10% of cases. In the review above, which brought together patients who had had a biopsy, mild cell abnormality (dysplasia) was found in the tissue in 34.2%, moderate in 27.5% and severe in 14.9%, and the rate of turning into cancer came out at 14%. This second rate needs reading with care: because the studies in the review were made up of patients examined by biopsy, this rate is not the risk for everyone with actinic cheilitis.

There are particular signs and factors that increase the risk. In the same review, crusts, sores and red areas were found to be linked to lip cancer. DermNet lists smoking, human papillomavirus (HPV), heavy alcohol use and suppression of the immune system (for example, medicines after an organ transplant) as factors that make progression to cancer easier. It also states separately that stopping smoking reduces the cancer risk in smokers. That is why two lips with the same appearance may need different follow-up frequencies depending on the person's history.

The good side of the picture is that actinic cheilitis is a condition that can be noticed early and treated. DermNet writes that it can improve with effective sun protection and treatment, but that continued sun exposure and leaving it untreated increase the risk of squamous cell carcinoma. In practice there are two separate questions: Is there a spot on this lip right now that raises a suspicion of cancer? Or does the whole lip carry widespread sun damage? The answer to the first question is a biopsy; the answer to the second is treatment and regular follow-up.

The first list describes the typical picture that suggests actinic cheilitis; the second list describes the signs that suggest a more serious change and need an examination without waiting. Examination and, if needed, a biopsy make the definite distinction.

The sequence below moves from the observation you can make at home to the doctor's assessment.

1. 1

   Compare your two lips in the mirror

   In daylight, look at your lower lip side by side with your upper lip. Is the border line sharp or blurred? Is there scaling, a white or red area, a crust or a sore? Take a photo; it is useful for comparing a few weeks later.

2. 2

   Stop the irritants and wait 2–3 weeks

   Stop licking your lips, cut out menthol, camphor, eucalyptus and flavoured products, and use a non-irritating lip protector with SPF 30 or above. The AAD recommends seeing a dermatologist if there is no improvement in 2–3 weeks despite this care. If there is a sore, a crust or a hard spot, do not apply this waiting period.

3. 3

   Examination: a dentist or a dermatologist

   DermNet writes that actinic cheilitis is often recognised by examination. The doctor asks about your sun exposure, your work, your smoking and your immune status, and also examines the lip by touch. A dentist can look at the lip at a routine check-up too and refer you to the appropriate specialist.

4. 4

   A biopsy if needed

   If cancer or another lip inflammation is suspected, a small tissue sample is taken from the most suspicious spot. The biopsy shows the degree of cell abnormality (dysplasia) and determines the scope of treatment.

5. 5

   Differential diagnosis

   Conditions that can look similar include allergic or irritant lip inflammation, lichen planus, discoid lupus and cracks at the corners of the mouth. A multicentre study by the International Dermoscopy Society showed that examination with magnification (dermoscopy) gives clues, but that there is no single imaging finding that definitely separates these conditions. When a definite distinction is needed, a biopsy is done.

6. 6

   Treatment and follow-up plan

   Cream, freezing, laser or surgery is chosen according to the findings and the biopsy result. Cleveland Clinic recommends check-ups every 6 to 12 months after treatment and a yearly skin examination.

There is no single treatment for actinic cheilitis proven to be best for everyone. A systematic review published in 2026 writes that the most effective treatment still cannot be determined, because comparative studies are few and most have a high risk of bias. The choice is made according to the biopsy result, how widespread the damage is and your own preference.

The following are the wrong decisions commonly seen with this picture, and what they cost.

The duration and the healing vary with the treatment chosen; the plan given by the doctor treating you takes priority. What they have in common is that follow-up and sun protection carry on after treatment.

1. During treatment

   With creams and photodynamic therapy, redness, crusting, burning and tenderness of the lip are an expected reaction. This reaction shows that the treatment is targeting the damaged cells; if it is severe, your doctor can adjust the application.

2. The first period after laser or surgery

   There is crusting and tenderness until the lip surface has renewed itself. In the 2021 review, side effects were generally mild. During this period, keeping the lip moist and protecting it from the sun matter.

3. The first check-up

   The doctor looks at whether the lip has cleared completely. In the 2026 review, the results of comparative studies were assessed at 3 and 6 months; if an area remains, further treatment is planned.

4. The long term

   Cleveland Clinic recommends a lip check-up every 6 to 12 months and a dermatological skin examination once a year. On a lip whose sun exposure continues, it can come back; in the 2025 meta-analysis, recurrence rates varied with the treatment.

We do not give a single figure, because with actinic cheilitis the route divides according to the examination and the biopsy result. The items that determine it:

The need for a biopsy

If there is a suspicious spot, taking a tissue sample and a pathology examination become part of the plan.

The treatment chosen

Creams applied at home, photodynamic therapy, laser and surgery need different equipment, time and numbers of sessions.

How widespread the damage is

A single area and damage covering the whole lip need treatment of a different scope.

Follow-up

Regular check-ups after treatment and, if needed, further applications are part of the process.