Thank you for your question. The medical term for a feeling of pins and needles in any part of the body is called paraesthesia. It occurs due to some disturbance to the nerve that supplies the sensation to the skin on that part of your body that you experience paraesthesia. The causes of paraesthesia depend whether it is transient (temporary) or chronic and range from pressure on the nerve that supplies the sensation to the skin on the part of your body that you experience paraesthesia to diabetes, vitamin deficiencies and neurological conditions.
Most people do experience paraesthesia from time to time. One of the most common paraesthesia occurs when someone feels his/her “hand/arm or leg sleeping” when there is pressure applied on the nerve (that supplies the arm or leg respectively) for a prolonged period of time. This is reversible and goes away when the pressure is removed.
Since the paraesthesia occurs behind your right ear, your general practitioner will likely ask you for any symptoms in the ear, nose, throat, head & neck region. If a full medical history as well as a head, neck and neurological examination fail to reveal the cause of your paraesthesia, it is best to consult a neurologist (brain doctor) who may order a series of blood tests and a scan to exclude any disturbances to the nervous system. Hope this helps!