Actinic keratosis (AK), sometimes referred to as solar keratosis or sun spots, is a precancerous skin condition resulting from abnormal keratinocyte proliferation and differentiation due to prolonged sun exposure. Other risk factors include a weakened immune system and certain genetic diseases. AK lesions typically present as red, scaling papules or plaques on a sun-exposed area and often occur as multiple lesions. The surrounding areas may show evidence of sun damage, with broken blood vessels, yellowish discoloration, and blotchy pigmentation. Lesions can progress to thickened, hypertrophic areas.
AK is the initial lesion in a disease continuum that progresses to invasive squamous cell carcinoma (SCC). In one study, 97% of SCCs were associated with AK. Thus, an AK patient can face a lifetime of treatment.
The main types of treatments for AK are:
• Topical therapy
• Liquid nitrogen/cryotherapy
• Photodynamic therapy
Sometimes a combination of these therapies is used. The choice of treatment may vary with the location, the type and extent of lesions, experience with previous treatments, presence of subclinical lesions, patient preference, and changes in a lesion that may indicate malignancy.