Diffuse actinic keratinocyte dysplasia (Q43976)

Diffuse actinic dysplasia develops after repeated exposure of skin to ultraviolet radiation, usually over decades, and results from cumulative DNA damage within the nuclei of epidermal keratinocytes. It is characterised initially by subtle diffuse skin changes including mottling, erythema, telangiectasia and irregular fine scaling. It is seen most commonly on the unprotected scalp skin of bald men. Histologically there are early signs of dysplasia in the basal epidermis. As damage accumulates the clinical changes become more pronounced with the formation of discrete actinic keratoses, from which intraepidermal or invasive squamous cell carcinoma may develop.