WartsWarts are epidermal growths associated with human papilloma virus (HPV) infection. Histologically they are characterized by- hyperkeratosis (hypertrophy of the horny layer) - acanthosis (hypertrophy of the spinous layer) - papillomatosis -  Koilocytes (large keratinocytes with eccenteric nuclei) are seen Different morphologic types of warts occur on different parts of body.Verruca vulgaris (or common wart) - fingers and toes Verruca plantaris (plantar warts) - soles & palms Verruca plana (flat warts) - face, legs & hands Condylomata acuminata (veneral warts) - moist areas around the vulva, arms & scrotumTreatment-  - warts can be removed by a number of chemicals, including formalin, podophyllum etc. - surgical excision or curettage with electrodessication can also be used. - treatment of extensive areas of skin requires surgical excision under general anaesthesia.Recurrences are common Some warts are risk factors for squamous cell carcinomaCorns & Callosities Corns and callosities both are hyperkeratosis due to chronic excessive pressure or friction on the skin (for eg. callosities on the hands of gardeners and labourers)