Between 5% to 10% of these lesions will develop into squamous cell carcinoma, a potentially invasive type of skin cancer.
Actinic keratosis (AK), also known as solar keratosis, is a precancerous growth that forms on skin damaged by prolonged exposure to ultraviolet (UV) light.
AK is the most common precancerous growth on the skin, affecting about 58 million Americans, according to the Skin Cancer Foundation.1
Between 5% to 10% of these lesions will develop into squamous cell carcinoma (SCC), a potentially invasive type of skin cancer. Because the damage caused by UV light is cumulative, an individual with 1 keratosis is likely to get more over time, which increases the overall risk of developing an SCC. Therefore, it is best to identify and treat them early on.1
This disease affects about 58 million Americans in the United States and was first described by Dubreuillh more than 100 years ago.2 The annual cost of treating skin cancers in the United States is estimated at $8 billion, which includes treatment options for patients with melanoma cancer and nonmelanoma.3 The lesions may present themselves in patients as young as 20 years of age but most commonly are noticeable in patients older than 50 years of age.4
AK lesions are commonly found on areas of the body with the most sun exposure, such as the arms, ears, face, scalp, and shoulders. In addition, individuals with compromised immune systems, fair complexions, a history of sunburns, and light hair are at particular risk. An AK lesion can be identified through its appearance, which presents as small brown, pink, or red discolorations on the skin. Because these lesions are often rough and scaly in texture, they can also be identified through touch. Affected areas can also be accompanied by a burning, itching, or stinging sensation.1
A suspected AK lesion should be examined by a board-certified dermatologist as soon as possible, especially those found on the head and neck, as skin cancers in those areas tend to be more aggressive. Once diagnosed, patients have a variety of treatment options available, depending on the location, number of lesions, and other patient factors, such as age and overall health.1
Surgical intervention is often used in cases of isolated lesions to remove the affected area and allow for new skin to grow. These procedures include chemical peels, cryosurgery, curettage and desiccation, and laser surgery to burn, freeze, or otherwise debride the damaged cells. A variety of topical treatments are available to patients with numerous or widespread keratoses and may be used to treat lesions that are not yet visible on the skin. 5-fluorouracil (Carac, Efudex, Fluoroplex), Diclofenac (Solaraze), hydraulic acid, Imiquimod (Aldara, Zyclara), and Ingenol mebutate (Picato) are some medications approved to treat AK lesions. Another option for widespread keratoses is photodynamic therapy in which blue or red light is used following the application of a light-sensitizing topical agent to destroy the keratoses. However, this treatment option is often reserved for patients with recurrent AK lesions post-treatment.1
The FDA recently approved Tirbanibulin (Klisyri; Almirall, S.A.) for the topical treatment of AK on the face and scalp. This prescription drug is available as a 1% ointment and comes in single-dose packets intended to be used once daily for 5 consecutive days. Common adverse effects include application site itch, pain and skin reactions. Additionally, patients should avoid applying near the eye areas, as it may cause irritation upon exposure.5,6
Saro Arakelians, PharmD, is vice president of pharmacy operations at a pharmacy in the Los Angeles, California, area. Ngoctran Tran is a PharmD candidate at the University of Southern California School of Pharmacy in Los Angeles.