Current therapies for actinic keratosis.

Actinic keratosis (AK) is a very common skin disease caused by chronic sun damage, which in 75% of cases arises on chronically sun-exposed areas, such as face, scalp, neck, hands, and forearms. AKs must be considered an early squamous cell carcinoma (SCC) for their probable progression into invasive SCC. For this reason, all AK should be treated, and clinical follow-up is recommended.

Dermatoscopic features of Koebner phenomenon in lichen planus on light and dark skin.

The Koebner phenomenon is well described and well known in clinical practice. Sometimes it can take on a linear appearance, the diagnosis of which can be facilitated by the use of dermatoscopy. In this case, we present a comparison between a linear Koebner phenomenon on light and dark skin, reporting the salient dermatoscopic characteristics and relating them to histopathology.