Actinic keratosis is considered precancerous and is often thought of as the beginning stages of squamous cell carcinoma. Around 10 % of all actinic keratosis will develop into skin cancer, however most squamous cell carcinomas begin as actinic keratosis that have been left untreated. Individuals who develop one of these sores are likely to develop others.
Developing actinic keratosis is a clear sign of sun damage that should not be taken lightly. You should seek treatment from a dermatologist, exercise more caution exposing skin to the sunlight, and practice regular self-inspections to identify any new growths as soon as possible.