Eruption as a dermatological disease is often localized, which is not fully explained by Western medicine. However, localization of eruption is interpreted in Kampo medicine according to meridian and collateral theo­ries, and here, we report two cases of successful treatment with Kampo medicine. Case 1 was of a 32-year-old woman who visited our clinic because of localized eruption around her mouth and was diagnosed with acne vulgaris. She was administered rikkunshito effectively. Case 2 was of a 37-year-old man who visited our clinic because of localized eruption in the anterior portion of the neck and was diagnosed with atopic dermatitis. He was administered shin'iseihaito effectively. Rikkunshito and shin'iseihaito are generally not adapted for dermatological diseases but were effective. After treatment we considered meridian and collateral theories. These two cases are depended on stomach meridian of foot-yangming and large intestine meridians of hand­-yangming, rikkunshito and shin'iseihaito were consisted of herbs concerning with spleen and lung meridians. Two cases were successfully treated through spleen meridian of greater yin and hand great yin lung meridian, which make exterior and interior with stomach meridian of foot-yangming and large intestine meridians of hand-yangming. Kampo medicine was effective for treating these diseases based on meridian and collateral theories.