Actinitic keratosis: causes, symptoms, diagnosis, treatment

Actinic keratosis (syn.: senile keratosis, solar keratosis) develops as a result of prolonged exposure of exposed skin areas to ultraviolet rays, usually in people over 50 years of age. It is a precancerous skin condition and is characterized by the formation of dry, rough, flat or slightly raised spots or plates on the skin, which can be multi-colored (from red to brown) and often range in size from a few millimeters to several centimeters.

Actinic keratoses are a warning sign of possible skin cancers, including skin cancer. Although not all actinic keratoses will necessarily develop into cancer, they require attention and treatment to prevent potential complications.

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Causes actinic keratosis

Actinic keratosis usually develops from long-term and repeated exposure of the skin to ultraviolet (UV) rays from the sun. The main causes include:

1. Long-term sun exposure: Frequent and prolonged sun exposure without protection from UV rays can lead to cumulative skin damage.
2. Repeated sunburn: It is especially important to avoid sunburn.
3. Skin changes with age: As we age, the skin loses its natural ability to protect itself from UV rays, making older people more susceptible to developing actinic keratosis.
4. Genetic predisposition: Heredity may play a role in the development of this condition. If family members have had similar growths, you may be at increased risk.
5. Fair Skin Type: People with fair skin and less melanin in their skin are more susceptible to damage from UV rays and therefore more likely to develop actinic keratosis.
6. Other risk factors: Risk factors also include prolonged sun exposure in hot climates, frequent use of tanning beds, and radiation treatments.

Avoiding long-term and intense exposure to UV rays and properly protecting your skin when in the sun are important preventive measures for this disease.

Pathogenesis

Pathomorphology. The leading changes in the epidermis are foci of disorganization of epithelial cells with atypia of the nuclei of the Maligian layer. The following variants of actinic keratosis are distinguished: hypertrophic, atrophic and bowenoid, lichenoid variant.

In the hypertrophic variant, hyperkeratosis with foci of parakeratosis predominates. Slight papillomatosis is noted. The epidermis is unevenly thickened with proliferation of epidermal processes into the dermis. Epithelial cells lose polarity, polymorphism and atypia are observed among them. Sometimes thickening of the granular layer and perinuclear edema are noted.

The atrophic variant is characterized by epidermal atrophy, atypia of the basal layer cells, which can proliferate into the dermis in the form of tubular structures. Often, cracks and lacunae are found under the basal layer, which resembles Darier's disease.

The Bowenoid variant does not differ histologically from Bowen's disease. The lichenoid variant differs very little clinically and histologically from lichen planus. It is characterized only by epithelial cell atypia.

In all variants of actinic keratosis, basophilic destruction of collagen and a dense inflammatory infiltrate consisting mainly of lymphocytes are observed in the dermis.

Histogenetically, actinic keratosis is associated with the epidermis. Differential diagnosis is made with keratotic papilloma, seborrheic keratosis, Bowen's disease.

Symptoms actinic keratosis

The lesions are mostly located on the face and back of the hands, less often in the lower third of the forearms, and are sharply defined, dry, erythematous, slightly infiltrated spots or plaques of small size, covered with tightly adhering yellowish-brown scales, after removal of which pinpoint bleeding appears. The adjacent areas of the skin under the influence of prolonged exposure to sunlight are often atrophic with telangiectasia and dyschromia. Actinic keratosis can transform into squamous cell carcinoma, and basalioma develops less often.

Diagnostics actinic keratosis

Diagnosis is usually based on a visual examination of the skin lesions by a physician, usually a dermatologist. The physician will perform the following steps to make a diagnosis:

1. Visual examination: The doctor will evaluate the skin and look for spots, warts, or plaques that may be signs of actinic keratosis. He or she may also note their color, size, shape, and texture.
2. Dermoscopy: To examine skin lesions in more detail, your doctor may use a dermatoscope, which magnifies the image and allows you to more accurately identify signs of actinic keratosis.
3. Biopsy: In some cases, your doctor may decide to perform a biopsy to confirm the diagnosis or rule out skin cancer. In a biopsy, a small sample of tissue is removed for testing in a lab.
4. Photography: Sometimes your doctor may take photographs of actinic keratoses to document and monitor progress.

When diagnosed, it is important to consider that this is a precancerous skin condition and steps must be taken to treat and control it. In addition, actinic keratosis may be an indicator of an increased risk of developing skin cancer, so it is important to have regular dermatological examinations and follow skin cancer prevention measures such as sun protection and avoiding sunburn.

Differential diagnosis

Differential diagnosis involves identifying and distinguishing this precancerous skin condition from other dermatological diseases. It is important to conduct an accurate diagnostic examination to choose the right treatment. Here are some conditions and diseases that may require differential diagnosis of actinic keratosis:

1. Basal cell carcinoma (BCC): Basal cell carcinoma is the most common type of skin cancer. In its early stages, it can resemble AK, so it is important to perform a biopsy for an accurate diagnosis.
2. Squamous cell carcinoma: This is a more aggressive type of skin cancer that can mimic actinic keratosis. A biopsy and additional testing can help differentiate the two.
3. Seborrheic keratoses: Seborrheic keratoses can have a similar appearance to AK, but they are usually located differently and are not related to sun exposure.
4. Keratoacanthoma: This is a fast-growing skin tumor that may resemble AK. A biopsy can differentiate the two.
5. Post-infectious and post-traumatic skin changes: Certain skin conditions may have a similar appearance to AK, especially after exposure to infection or trauma. In this case, it is important to pay attention to the medical history and conduct additional tests if necessary.
6. Lichen planus (lichen planus): This is a chronic dermatological condition that may have similar features to AK. Diagnosis may also require a biopsy.
7. Black spots or melanocytic nevi: Harmless moles and skin spots can look like AK, but they have different characteristics.

To accurately diagnose actinic keratosis and rule out other conditions, you should consult a qualified dermatologist. A biopsy and additional laboratory tests may be necessary for a definitive diagnosis.

Treatment actinic keratosis

Treatment of actinic keratosis (solar keratosis) may involve various methods, and the choice of a particular method depends on the characteristics of the skin lesions, their number and location, as well as the individual characteristics of the patient. The main treatment methods are listed below:

1. Cryotherapy (freezing): This treatment involves using liquid nitrogen to freeze and destroy tumors. Frozen growths often die and flake off within a few weeks.
2. Using creams: Special creams and ointments containing acids, such as 5-fluorouracil or imiquimod, are used to treat the growth. These medications are applied to the affected areas of skin and can help shrink the growth.
3. Laser therapy: Laser removal can be an effective method. The laser beam is used to target the keratoses to specific areas.
4. Surgical removal: If tumors are large or deeply embedded in the skin, they may be surgically removed.
5. Photodynamic therapy: This method involves applying a photosensitizing drug to the skin and then irradiating the lesions with a laser or other light source, which causes them to be destroyed.
6. Electrocoagulation: This method uses an electric current to remove actinic keratoses.
7. Liquid nitrogen skin treatment (cryosurgery): The doctor applies liquid nitrogen directly to the skin to destroy tumors.
8. Medications: In some cases, topical medications such as retinoids are used to help reduce the size and number of growths.

When treating, it is important to follow your doctor's recommendations, have regular check-ups, and take good care of your skin. It is also important to take skin cancer prevention measures, such as sun protection and regular dermatological examinations.

Prevention

Prevention of actinic keratosis involves protecting the skin from the sun's ultraviolet (UV) rays and minimizing exposure to other risk factors. Here are some recommendations for prevention:

1. Use sunscreen: Apply sunscreen regularly to your skin. Use products with broad spectrum UVA/UVB protection and a high SPF (sun protection factor).
2. Limit time in the sun: Try to avoid prolonged sun exposure, especially during peak sun hours (10:00 a.m. to 4:00 p.m.). Try to stay in the shade and wear protective clothing, including a wide-brimmed hat and sunglasses.
3. Avoid sunburn: Avoid sunburn as it can increase the risk of developing actinic keratosis and skin cancer.
4. Use sun protection in your daily life: In addition to sunscreens, you can use sunscreens, clothing and accessories that have UV protection.
5. Skin self-examination: Regularly examine your skin for new or changing growths. If you notice any suspicious changes, see a doctor immediately.
6. Avoid tanning beds: Using tanning beds increases the risk of developing actinic keratosis and skin cancer. It is recommended to avoid visiting tanning beds.
7. Maintain a healthy lifestyle: Maintain a healthy lifestyle, including eating a healthy diet, not smoking, and drinking alcohol in moderation. These factors can help promote healthy skin.
8. Regular dermatological examinations: Visit a dermatologist regularly to monitor the condition of your skin and detect new growths.

Prevention is an important step in reducing the risk of developing precancerous skin conditions and skin cancer. Following the steps above will help protect your skin from the harmful effects of UV rays and keep it healthy.

Forecast

The prognosis of actinic keratosis (solar keratosis) varies depending on various factors such as the size, number, and location of the lesions, as well as the response to treatment and prevention. It is important to understand that these lesions are a precancerous skin condition, and their prognosis is related to the risk of developing skin cancer, especially squamous cell carcinoma.

The forecast may be as follows:

1. Development of skin cancer: The main danger of these tumors is their ability to progress to squamous cell carcinoma of the skin. However, not all actinic keratoses develop into cancer, and the risk of this depends on many factors.
2. Effective treatment: Timely consultation with a doctor and effective treatment of neoplasms can help prevent its progression and the development of skin cancer.
3. Prevention: Taking preventive measures, such as sun protection and regular dermatological examinations, can reduce the risk of these growths returning and developing skin cancer.
4. Individual characteristics: The prognosis also depends on the individual characteristics of the patient, including his or her genetic predisposition to skin cancer and the ability to heal skin lesions.
5. Following your doctor's advice: It is important to follow your doctor's advice, take prescribed treatments, and have regular medical checkups.

General recommendations for patients include regular follow-up and monitoring by a dermatologist, preventive measures such as sun protection, and effective treatment. Early detection and treatment play an important role in preventing the development of skin cancer and improving the prognosis.

Some classic books and authors in the field of oncology that may be helpful

1. "Cancer: Principles & Practice of Oncology" (Book on the principles and practice of oncology) - Authors: Vincent T. DeVita Jr., Theodore S. Lawrence, Steven A. Rosenberg, et al.
2. "The Emperor of All Maladies: A Biography of Cancer" - By Siddhartha Mukherjee
3. "Oxford Textbook of Oncology" - Authors: David J. Kerr, Daniel G. Haller, Cornelis JH van de Velde and others.
4. "Principles and Practice of Gynecologic Oncology" - Authors: Dennis S. Chi, Andrew Berchuck, Robert L. Coleman, et al.
5. "The Biology of Cancer" - Author: Robert A. Weinberg
6. "Clinical Oncology" - Authors: Martin D. Abeloff, James O. Armitage, John E. Niederhuber, et al.
7. "Oncology: An Evidence-Based Approach" - Authors: Alfred E. Chang, Patricia A. Ganz, Daniel F. Hayes, et al.

References

• Chissov, V. I. Oncology: National Guide. Brief edition / edited by V. I. Chissov, M. I. Davydov - Moscow: GEOTAR-Media, 2017.
• Butov, Yu. S. Dermatovenereology. National leadership. Brief edition / ed. Yu. S. Butova, Yu. K. Skripkina, O. L. Ivanova. - Moscow: GEOTAR-Media, 2020.