Actinic Keratosis

Definition

Definition of Actinic Keratosis
Actinic keratosis (also called "solar keratosis" and "senile keratosis") is a premalignant condition of thick, scaly, or crusty patches of skin. It is more common in fair-skinned people. It is associated with those who are frequently exposed to the sun, as it is usually accompanied by solar damage. Since some of these pre-cancers progress to squamous cell carcinoma, they should be treated. Untreated lesions have up to twenty percent risk of progression to squamous cell carcinoma.

When skin is exposed to the sun constantly, thick, scaly, or crusty bumps appear. The scaly or crusty part of the bump is dry and rough. The growths start out as flat scaly areas, and later grow into a tough, wart-like area.

Symptoms

Symptoms of Actinic Keratosis

1. Painless skin lump
2. Discolored skin lump
3. Flesh-colored skin lump

Causes

Causes of Actinic Keratosis
Years of sun exposure cause AKs to develop. All AKs, including actinic cheilitis, develop in the skin cells called the “keratinocytes,” which are the tough-walled cells that make up 90% of the epidermis, the outermost layer of skin, and give the skin its texture. Years of sun exposure cause these cells to change in size, shape, and the way they are organized. Cellular damage can even extend to the dermis, the layer of skin beneath the epidermis.

Diagnosis

Diagnosis of Actinic Keratosis
Doctors can usually identify AK by doing a thorough examination. A biopsy may be necessary when the keratosis is large and/or thick, to make sure that the bump is a keratosis and not a skin cancer. Seborrheic keratoses are other bumps that appear in groups like the actinic keratosis but are not caused by sun exposure, and are not related to skin cancers. Seborrheic keratoses may be mistaken for an actinic keratosis.

Prognosis

Prognosis of Actinic Keratosis
Consult with your doctor.

Treatment

Treatment of Actinic Keratosis
Various modalities are employed in the treatment of actinic keratosis:

1. Diclofenac sodium 3% gel, a nonsteroidal anti-inflammatory drug. Recommended duration of therapy is 60 to 90 days.
2. Cryosurgery, e.g. with liquid nitrogen, by "freezing off" the AKs
3. 5-fluorouracil (a chemotherapy agent): a cream that contains this medication causes AKs to become red and inflamed before they fall off
4. Photodynamic therapy: this new therapy involves injecting a chemical into the bloodstream, which makes AKs more sensitive to any form of light.
5. Laser, notably CO2 and Er:YAG lasers. A Laser resurfacing technique is often used with diffuse AKs.
6. Electrocautery: burning off AKs with electricity
7. Immune Response Modifier: topical treatment with imiquimod (Aldara), an immune enhancing agent

Prevention

Prevention of Actinic Keratosis
Preventive measures recommended for AK are similar to those for skin cancer:

1. Not staying in the sun for long periods of time without protection (e.g., sunscreen, clothing, hats).
2. Frequently applying powerful sunscreens with SPF ratings greater than 30 and that also block both UVA and UVB light.
3. Wearing sun protective clothing such as hats, long-sleeved shirts, long skirts, or trousers.
4. Avoiding sun exposure during noon hours is very helpful because ultraviolet light is the most powerful at that time.