What is Actinic Keratosis?
Actinic Keratosis, also known as a solar keratosis, is a pre-cancerous form of Squamous Cell Carcinoma of the skin arising from the flat (squamous) cells in the uppermost layers of the skin known as the epidermis.
They usually present as scaly or crusted areas on the surface of the skin.
You will often see the plural, “Actinic Keratoses,” because they are often multiple and are the most common lesions treated at the My Skin Clinic.
Often Actinic Keratoses are so small that they can only be detected by expert examination. Patients may have many times more invisible (subclinical) lesions than those that appear on the surface.
Studies state that up to 20% can progress to become Squamous Cell Carcinoma or other skin cancers
When treated early the vast majority of Actinic Keratosis are not serious and their significance lies in their potential to transform, and in cases of heavy encrustation, to cause cosmetic impact that in severe cases can be significant.
Actinic Keratosis Risk Factors
Anyone with a history of sun exposure can develop Actinic Keratosis. However groups of people at greater risk include:
- Fair Skin Types
- people who are at highest risk have fair skin, freckles, blond or red hair, and blue, green, or grey eyes. They have a tendency to burn rather than tan.
- Prior Actinic Keratoses
- People who have had prior AK diagnosis or an increased number of unusual moles.
- Prior Skin Cancer
- People who have had one Actinic Keratosis are at risk for developing others, in the same area or elsewhere on the body. If you’ve had a Actinic Keratosis you have a 10 times higher risk of developing another skin cancer of any type and so routine reviews are advised on a 6 monthly basis.
- Family History
- The tendency to develop Actinic Keratosis may also be inherited. People genetic disorders like Xeroderma Pigmentosa - which causes photosensitivity.
- Older People
- Actinic Keratoses is common in people over the age of 50. The number of Actinic Keratoses increases dramatically with age, with an untreated individual in their 70’s likely to have 35 times the number of Actinic Keratoses vs when they were in their 50's. Some experts believe almost everyone over 80 has Actinic Keratoses.
- Weak Immune Systems
- Patient with immunosuppression from any cause: HIV, immunosuppression after transplants etc.
- Occupational
- Workers in occupations that require long hours outdoors or people who have an exposure to cytotoxics such as aniline dyes in the printing industry.
- Recreational
- People who pursue outdoor recreation activities for hours at a time.
Where Are Actinic Keratosis Found?
Actinic Keratoses most often appear on the bald scalp, face, ears, lips, back of the hands and forearms, shoulders, neck or any other areas of the body frequently exposed to the sun.
They most commonly occur on the face and the back of the hands.
Another form of Actinic Keratosis, actinic cheilitis, develops on the lips and may also evolve into squamous cell carcinoma.
Actinic Keratoses are usually multiple and commonly occur in areas known as ‘fields’. The localised nature of this pre-cancerous change is known as ‘field change’ and includes visible and invisible (subclinical) Actinic Keratoses.
Why Actinic Keratosis Is a Concern?
Although the vast majority of Actinic Keratoses remain benign, some studies report that up to twenty percent can progress and become Squamous Cell Carcinoma.
This percentage does not sound very large, but it is significant. With Squamous Cell Carcinomas, 40-60 percent begin as untreated Actinic Keratoses and may invade surrounding tissues or spread to other areas of the body (metastasise). About 2 to 10 percent of these Squamous Cell Carcinomas spread which can be life-threatening.
The more Actinic Keratoses you have, the greater the chance that one or more may turn into Squamous Cell Carcinoma. In fact, some researchers regard Actinic Keratoses as an early highly localised form of Squamous Cell Carcinoma.
What Causes Actinic Keratosis?
95% of Actinic Keratosis in Australia are the result from skin damage caused by
- Cumulative long-term sun exposure
- Intermittent overexposure to ultraviolet (UV) radiation from the sun (typically leading to sunburn)
Cloudy days aren’t safe, because 70-80 percent of solar ultraviolet (UV) rays can pass through clouds. These harmful rays can also bounce off sand, snow and other reflective surfaces, heightening UV exposure. This is especially the case at higher altitudes.
The ultraviolet radiation given off by the lamps in a tanning salon can be even more dangerous than the sun, so our Doctors warn against using sunbeds.
Most Actinic Keratoses occur on parts of the body exposed to the sun — especially the face, ears, neck, scalp, shoulders, and back, but many can be found in areas that are only burned or exposed occasionally - such as the abdomen or upper thighs
It is often not possible to pinpoint a precise, single cause for a specific Actinic Keratosis. Some Actinic Keratoses can also result from less common causes such as:
- contact with arsenic,
- exposure to ionising radiation such as X-rays (used in radiotherapy)
- open sores that resist healing,
- chronic inflammatory skin conditions, and
- as complications of burns and scars.
- Also, individuals whose immune defenses are weakened by cancer chemotherapy, AIDS, organ transplantation or excessive UV exposure are less able to fight off the effects of the radiation and thus more likely to develop Actinic Keratoses.
When an Actinic Keratosis is suspected to be an early Squamous Cell Carcinoma, your Doctor may take tissue for biopsy. This is done by doing a punch biopsy, or shaving off the top of the lesion with a scalpel, or scraping it off with a curette. Local anesthesia is required. Bleeding is usually stopped with a styptic agent or by placing light sutures to counter the small amount of bleeding that may ensue.
Stages of Actinic Keratosis
In the beginning, Actinic Keratoses are so small that they can only be detected by expert examination. Over time they enlarge to a size where the patient becomes aware of them by touch and feel as if you were running your finger over sandpaper. As they progress they may become large enough to be seen with the naked eye.
Most often, Actinic Keratoses develop slowly and reach a size between 2mm to 4mm. Early on, they may disappear only to reappear later.
Though less than 20 percent of Actinic Keratoses transform into Squamous Cell Carcinoma there is no way to know which will transform. Fortunately there are a number of highly effective treatments for them.
What Are the Symptoms of Actinic Keratosis?
If you have Actinic Keratoses, it indicates you have chronic sun damage and could be at higher risk of any kind of skin cancer – not just Squamous Cell Carcinoma. A key factor used to identify an Actinic Keratosis is any ongoing crusting change persists beyond a few weeks in a lesion on the skin.
If you observe two or more of the signs below, you should consult the My Skin Clinic immediately.
- A pigment change
- as well as freckles, “age spots,” skin that is red is an indicator, but some will be light or dark tan.
- A Sore
with a crusted surface that crusts, only to heal up again. A persistent, non–healing sore is a very common sign of early Actinic Keratosis. In rare instances, Actinic Keratoses can even bleed
- A shiny area
that itches or produces a pricking feeling or sensation of tenderness
- A pink growth
with a slightly elevated rolled edge. The growth slowly enlarges, tiny blood vessels may develop on the surface.
Actinic Keratosis Warning Signs
At the My Skin Clinic we use the adage ‘The faster an Actinic Keratosis grows the faster it needs to go’.
Faster changing or growing Actinic Keratosis need your attention because it may be a precursor to or actually be a Squamous Cell Carcinoma. Any rapidly changing skin growth, should prompt an immediate visit to a My Skin Clinic.
Actinic Keratosis Screening
Diagnosis and management of Actinic Keratosis is best performed via a Full Body Scan. In the first incidence, this process includes
- Digitally Mapping a patient's entire body for any suspicious skin damage or lesion
- Followed by a detailed Dermoscopic examination by a trained skin cancer doctor.
- Recording and combining all images and skin metrics (size, shape, colour, and other attributes) into the patient record
Our expert Doctors at My Skin Clinic will then clearly identify and diagnose any skin disease.
Having a digital molemap or a baseline of all your skin’s moles skin for all family members with Actinic Keratosis, those with a large number of moles, or have been diagnosed with melanoma is recommended. Any changes can be more easily spotted and understood.
Untreated Actinic Keratosis
Actinic Keratoses respond well to early treatment. If untreated the consequences could include disfigurement from the Actinic Keratoses or their treatment, and up to and including death if transformation into Squamous Cell Carcinoma occurs and this is not treated early enough.
In 2016 it is estimated that there were 560 deaths in Australia from non-melanoma skin cancers. It is not possible to identify how many of these are Actinic Keratosis as this data is not separately recorded.
Actinic Keratosis Treatment Options
Almost all Actinic Keratoses (AKs) can be eliminated if treated early, before they become skin cancers.
Various treatment options are available, and selection criteria involve the particular lesion/s growth characteristics and the patient’s age and health. Some of these strategies may increase sun sensitivity, so be sure to follow the instructions given by the My Skin Clinic before commencing them and be especially diligent about using sun protection during the treatment period.