Effect of acupuncture on allergen-induced itch in patients with atopic eczema

Background Itch is a complex and unpleasant sensory experience that induces the urge to scratch and is a major symptom of allergic skin disease. Acupuncture has been shown to exhibit a significant positive effect on histamine-induced itch in healthy volunteers. Objective We investigated the effect of acupuncture on allergen-induced itch, and wheal and flare response in a double-blind, randomized, placebo-controlled, crossover trial. Methods A skin prick test (house dust mite or grass pollen) was applied to 30 patients with atopic eczema before (direct effect) and after (preventive effect) two experimental approaches of conditioning or control observation: acupuncture at points Quchi and Xuehai (A1, dominant side), “placebo point” acupuncture (A2, dominant side), no acupuncture (NA). Itch intensity was recorded on a visual analogue scale. After 10 min, wheal and flare size, as well as temperature, were measured at the stimulus site and the validated Eppendorf Itch Questionnaire (EIQ) was completed by the patient. Results Mean itch intensity was significantly lower in A1 (35.7±6.4) compared to NA (45.9±7.8) and A2 (40.4±5.8) with regard to the direct effect; and significantly lower in A1 (34.3±7.1) and A2 (37.8±5.6) compared to NA (44.6±6.2) with regard to the preventive effect. Mean wheal and flare size was significantly smaller in A1 (0.38±0.12 cm 2 /8.1±2.0 cm 2 ) compared to A2 (0.54±0.13 cm 2 /13.5±2.8 cm 2 ) and NA (0.78±0.28 cm 2 /15.1±4.1 cm 2 ) in the preventive approach. Skin temperature showed no significant difference between groups. Mean EIQ ratings were significantly lower in A1 compared to NA and A2 in the treatment approach; and significantly lower in A1 and A2 compared to NA in the preventive approach. Conclusions Acupuncture at the correct points reduced allergen-induced itch intensity and prevented wheal and erythema formation compared to placebo procedures in patients with atopic eczema.