Dandruff is seborrheic dermatitis which is caused from the Three Organ problems, not dispersing of Qi and Blood by Lung Qi and Kidney Yang. The function of the Lungs are to control the skin-hair and 'the pole'(sweating gland). According to TCM, the lung sends the blood and body fluid by pumping through all of the body. The Kidney receives the Qi which is coming from the Lungs. Also, the Kidneys transform Yin(Blood,body fluid) into urine by filtering. If they lose their function, it can create dandruff and skin trouble.
From Traditional Chinese Medicine theory, it is called "Bai xien Feng" which, laterally means "white scale wind"; it usually happens on the head. Also it happens on the skin, specially elbow knee, ear and, nape.
One has dandruff in the head with itching or without itching, the state of dandruff variys by ones constitution, some will only have dandruff just on the border line of the hair, while others can have it around the ear and some people can have it on the whole body.