What skin condition is indicated by a flattened papule with a dry scale, commonly found on the forehead of a retired farmer?

Actinic keratosis is characterized by a flattened papule with a dry scale, and it commonly appears on sun-exposed areas of the skin, such as the forehead. This condition often arises in individuals who have had significant sun exposure, which is typical for a retired farmer who may have spent many years outdoors.

Actinic keratosis is indicative of precancerous changes in the skin due to ultraviolet (UV) light damage. The scaly, rough texture of the lesion distinguishes it from other skin conditions. There often is a risk that untreated actinic keratosis can progress to squamous cell carcinoma, highlighting the importance of monitoring and potentially treating these lesions.

In contrast, seborrheic keratosis usually presents as a well-defined, raised, and often pigmented lesion that might have a "stuck-on" appearance. Basal cell carcinoma tends to appear as a pearly nodule or sore that doesn't heal, and melanoma usually manifests as an irregularly shaped, multicolored mole or lesion that can change over time. Each of these conditions has distinct characteristics that differentiate them from actinic keratosis.