Figure 1: An AD-like skin lesion from a conventional NC/Nga mouse (a). Conventional mice were subjected to strong or mild exercise. In the mice subjected to the strong exercise load, the skin symptoms worsened compared to the conventional mice with no exercise burden, but the symptoms were reduced in the mice with a mild exercise load. The SPF NC/Nga mice did not develop any eczematous lesions. The dermatitis score (b) for the rostral back was assessed after the final episode of treadmill running (0, none; 1, slight; 2, moderate; 3, severe). This scoring was based on the severity of erythema/haemorrhage and pilosis. (c) Mild exercise in mice increased the plasma β-endorphin levels in comparison with the no exercise mice, and strong exercise decreased the levels in comparison with the no exercise mice. Values are the means ± SD derived from 10 animals. *P<0.05 compared with the no exercise SPF or conventional NC/Nga mice.