The main pathological changes in the skin are: hyperkeratosis and abnormal proliferation of the epidermal stratum corneum and stratum spinosum cells, resulting in hypertrophy and hyperplasia of the epidermal layer, and the appearance of slightly raised warts. If you don’t treat your warts, you’ll be infected with other people; they’re usually found on the exposed parts of the face and can cause skin lesions, which can seriously affect your appearance.