The back of the head is a little itchy, in this case may be localized folliculitis, may also be sebaceous cysts. In this case keep the local clean and dry, you can apply iodophor disinfection, take some oral cephalosporin antibiotics, continue to observe, avoid staying up late, regular rest and light diet, avoid spicy and stimulating food, do not smoke and drink, avoid eating hot pot and other foods. In addition, you should also look at whether there are local inflammatory diseases of the skin, dermatitis and so on can apply some drugs such as dermatoprene.