The scalp, often forgotten in our sun protection routine, is nevertheless an area vulnerable to the harmful effects of UV rays. One of the major concerns in capillary dermatology is the actinic keratosis of the scalp, a pre-cancerous condition that can develop discreetly. Discover everything you need to know about actinic keratosis of the scalp : its signs, risks and solutions.
What is actinic keratosis of the scalp?
Actinic keratosis, also known as solar keratosis, is a skin condition considered precancerousIt is caused mainly by prolonged and repeated exposure to the sun's ultraviolet (UV) rays. It manifests itself as rough, often scaly lesions that can vary from flesh-coloured to a more pronounced red. These lesions can sometimes be accompanied by itching or sensitivity to touch, or even lead to hair loss in women in particular.
When actinic keratosis develops on the scalp, it is often seen in individuals with thinning hair or who are bald. The reason is simple: the scalp, when exposed to direct sunlight without protection (such as that provided naturally by the hair or by head coverings), is likely to accumulate UV damage over a long period.
Although actinic keratosis of the scalp may seem harmless, it is crucial to diagnose and treat it early. Left untreated, it can progress to a type of skin cancer known as squamous cell carcinoma. Early recognition and management are therefore essential to prevent complications.
Why is the scalp particularly vulnerable to actinic keratosis?
The scalp is particularly vulnerable to actinic keratosis for a number of reasons. The scalp is an area of the body which, when exposed, receives direct ultraviolet rays from the sun. In people with thinning or bald hair, this exposure is even more pronounced.
Many people do not apply sun cream to their scalp or wear a hat during prolonged exposure to the sun. Unlike other parts of the body, the scalp is often forgotten when it comes to sun protection.
The skin of the scalp is also different from that of other parts of the body. The sebaceous glands are more active, which can affect the way this area reacts to prolonged exposure to the sun.
The damage caused by UV rays is cumulative. Repeated and prolonged exposure to the sun without adequate protection can lead to an accumulation of damage over several years, making the skin of the scalp increasingly vulnerable to conditions such as actinic keratosis.
The combination of direct exposure, lack of protection and lack of awareness makes the scalp a prime target for actinic keratosis.
How can you recognise the symptoms of actinic keratosis on the scalp?
Actinic keratosis is a type of chronic condition particularly affecting people over the age of 60. Recognising the symptoms is crucial to early and effective treatment. There are several signs to look out for :
- The appearance of lesions: lesions caused by actinic keratosis are generally rough to the touch. They may be flat or slightly raised and often have a scaly or scaly surface.
- The colour of the lesions: lesions can vary in colour from pale pink to brownish red. They may also have a flesh-coloured appearance, which can sometimes make them more difficult to distinguish.
- Lesion size: although most lesions are small (less than a centimetre), they can increase in size over time.
- Sensations: some people experience itching, tingling or sensitivity in the affected area. However, not all actinic keratoses are necessarily symptomatic.
- Location of lesions: on the scalp, they are more frequently observed on the areas most exposed to the sun, in particular the top of the head or the forehead for people with a receding hairline.
If you notice one or more of these characteristics on your scalp or that of a loved one, it is strongly recommended that you make an appointment with a healthcare professional for an accurate diagnosis. Although actinic keratosis is precancerous, with early intervention the treatment outlook is generally very good.
Actinic keratosis and seborrhoeic keratosis: what are the differences?
Actinic keratosis and seborrhoeic keratosis are two skin conditions that may appear similar at first glance, but they are caused by different mechanisms and have distinct clinical implications.
Actinic keratosis is mainly caused by prolonged and repeated exposure to UV rays from the sun or tanning beds. By contrast, seborrhoeic keratosis, the exact origin of which is less clear, is often linked to genetic, hormonal or age-related factors. Seborrhoeic keratosis lesions are generally raised, with a warty appearance and a surface that may appear "oily". They may be brown, black, yellowish or flesh-coloured. Unlike actinic keratosis, they can develop anywhere on the body, including in areas not exposed to the sun. Although benign and not associated with cancer, they can be removed for cosmetic reasons or if they cause irritation.
What are the risks associated with actinic keratosis if it is left untreated?
Actinic keratosis is considered to be a precancerous lesion, and leaving it untreated can lead to a number of complications. The most worrying risk associated with untreated actinic keratosis is its possible transformation into squamous cell carcinoma (SCC), a type of skin cancer. Although not all actinic keratoses develop into cancer, a certain percentage do, hence the importance of early treatment.
If left untreated, actinic keratosis can cause itching, tingling or a burning sensation. In some cases, lesions may also bleed, particularly if they are scratched or rubbed. If left untreated, actinic keratosis can also encourage the development of other lesions on the skin, increasing the affected area and the associated risks.
How is actinic keratosis of the scalp diagnosed?
Diagnosis of actinic keratosis of the scalp involves several stages, mainly clinical, but sometimes supplemented by histological analysis.
It all starts with a clinical examination. This involves assessing the lesions on the scalp, noting their size, shape, colour and texture. To better visualise the skin structures and help distinguish actinic keratosis from other skin conditions, the scalp is often examined using a dermatoscope.
If the diagnosis is uncertain, a biopsy may be performed. This procedure confirms the presence of abnormal cells typical of actinic keratosis and excludes other conditions, such as squamous cell carcinoma.
Once the diagnosis has been confirmed, the healthcare professional will discuss treatment options tailored to the severity and extent of the lesions. It is essential to seek medical advice as soon as actinic keratosis is suspected. Early diagnosis and treatment are crucial in preventing possible complications.
How can actinic keratosis of the scalp be prevented?
The main way to prevent actinic keratosis of the scalp is to protect yourself from ultraviolet rays, which are the main cause of the condition.
- Regularly apply a sunscreen to the scalp, especially if you are bald or have thinning hair. Opt for a broad-spectrum sunscreen with a sun protection factor (SPF) of at least 30, with 50 being preferable.
- Wearing a wide-brimmed hat when going outdoors is an excellent way of protecting the scalp from direct UV rays. Make sure the hat is made of a dense material that doesn't let light through.
- It is advisable to avoid the sun during the hours when it is most intense, generally between 10am and 4pm. If this is not possible, seek shade or use a parasol.
- Check your scalp regularly for any suspicious changes or lesions.
Prevention also applies to the face and body:
- Wear sunglasses offering 100% protection against UVA and UVB rays to protect the delicate area around the eyes.
- Wear long clothing or sun protection to protect your skin from UV rays.
- Check your skin regularly for new moles or changes in the appearance of existing ones. Pay particular attention to areas that are frequently exposed to the sun.
By following these preventive measures, you can considerably reduce the risk of developing actinic keratosis of the scalp. The key is consistent sun protection and vigilance in the face of potential skin changes.
Jean-François Cabos is the creator of a unique hair care method based on the research he coordinated, which led to the publication of the book Hair, Roots of Life with Hélène Clauderer published by Robert Laffont (Collection "Réponses/ Santé").
