Fig 1.

Reaction to ingenol mebutate. Field cancerization of the skin was addressed with three cycles of ingenol mebutate (IM). Here, the third cycle of IM is depicted in an area larger than the registered 25 cm². The first day after applying 150 μg IM gel showed a pronounced local reaction with erythema, erosions, and hemorrhagic, yellowish crusting of occiput and vertex (A), with erythema and erosions of the left temporal fossa triangularis and the left ear (B), as well of the right temporal fossa (C). Five weeks after stopping the third cycle of 150 μg IM gel the erythema and erosions had improved significantly on occiput and vertex (D), with slight erythema with no erosions of the left temporal fossa triangularis and the left ear (E) and atrophied macula with slight erythema and a central superficial erosion of the right temporal fossa (F). Twenty five weeks after stopping the third cycle of 150 μg IM gel, a whitish macule remained on the vertex with sporadic crusts (G), with complete clinical remission of AK of left temporal fossa triangularis and the left ear (H), and atrophied macula of right temporal fossa triangularis (I) without erythema in all treated areas.