What is a cutaneous horn?

Question
I am a 32 years old woman and I have noticed a weird growth exactly like hair (thickness around 4 to 5 hairs put together) on my left arm. It is sharp. What is this and is it a common problem?
Expert Answer
J
What you have is a 'cutaneous horn'. A cutaneous horn, also known as cornu cutaneum, refers to a specific appearance of a skin lesion in which a cone-shaped protuberance arises on the skin caused by overgrowth of the most superficial layer of skin (epidermis). A cutaneous horn is not a particular lesion but is a reaction pattern of the skin, mostly a wart. Removal or excision is the best treatment.