Prevalence and factors associated with actinic keratosis in 1346 patients attending at a public dermatology service: a cross-sectional study.

Background: Actinic keratosis is a common preneoplastic dermatosis and is the third most common reason for dermatological consultations. Identifying the associated factors, diagnosis, and early treatment of actinic keratosis are crucial for reducing the risk of developing skin cancer and costs to the healthcare system.

Objective: To evaluate the prevalence and factors associated with actinic keratosis in individuals treated at a public dermatology service.

Design and setting: A cross-sectional observational study was conducted with 1346 patients treated by a public dermatology service.

Methods: The demographic and dermatological characteristics of patients were recorded. The presence of actinic keratosis was determined by clinical dermatological identification.

Results: Most participants were elderly, white, and exposed to the sun without protection or during occupational activity. The evolution time of cutaneous lesions was <1 year in 46.8% of participants. Actinic keratosis was the most common skin lesion, being present in 29.3% of participants. The main approach adopted was cryotherapy. Keratosis was associated with white skin color, elderly age, personal and family history of skin cancer, exposure to the sun without protection at work, and limb involvement. When the associated factors were analyzed using a regression model, skin color and affected body segments were the main predictors of actinic keratosis.

Conclusions: The prevalence of actinic keratosis was 29.3%, being higher in people with fair skin, more than two affected segments, skin lesions on the limbs, older age, and unprotected sun exposure. These indicators are important for supporting decision-making and contributing to improving public policies.