Hi! my friend has developed some small things on his head (skull) they look like dry warts. what is the cause n how can it be treated.

See a physician: Warts are caused by the HPV virus. There are many medications and alternative treatments that work. They also can be removed by a Dermatologist if needed. But before you consider self treatment be sure to have the involved area examined by a physician to be sure you are not dealing with a precancerous actinic keratosis or squamous cell cancer.