Dermoscopic features of actinic keratosis.

Actinic keratosis (AK) is a keratinocytic neoplasm that typically develops on sun-damaged skin of elderly individuals. Only a few reports so far have described the dermoscopic diagnostic features of AK, mainly focusing on facial non-pigmented AKs. A typical feature of facial non-pigmented AK is a composite pattern named "strawberry pattern", characterized by a background erythema/red pseudonetwork consisting of unfocused, large vessels located between the hair follicles, associated with prominent follicular openings surrounded by a white halo. Dermoscopic characteristics of pigmented AK on the face include multiple slate-gray to dark-brown dots and globules around the follicular ostia, annular-granular pattern and brown to gray pseudonetwork. Recognizing specific dermoscopic features of AK can be useful in guiding the clinician in the differential diagnosis of AK with melanocytic skin lesions such as LM and non-melanocytic lesions. Histopathologic examination should be performed whenever clinical and/or dermoscopic differential diagnosis is inconclusive.