Electrical ear acupuncture reduces histamine-induced itch (alloknesis)

In order to assess an objective measure for the outcome of ear acupuncture, we evaluated the effect of electrical ear acupuncture on areas of histamine-induced alloknesis in 32 healthy volunteers. In a first assessment 5 min after histamine application on both volar forearms, 16 subjects received right ear and 16 left ear acupuncture. Immediately before and 5 min after acupuncture, alloknesis areas on both forearms were planimetrically evaluated. A second assessment was carried out 4 weeks later with the same patients. They underwent histamine application once more, but received no acupuncture. Alloknesis areas were then compared with reference to time, assessment and therapy side. Forearms relating to ipsilateral acupuncture showed significantly reduced or even no alloknesis areas after therapy. On the contralateral sides and during the "non-acupuncture" assessment 4 weeks later, alloknesis areas were significantly enlarged compared with sides ipsilateral to right and left ear acupuncture. Hence, results verify the effects of electrical ear acupuncture by objective measures.