1临床资料患者女,21岁。躯干及四肢灰褐色斑片2年余。2年前无明显诱因患者胸部出现数个蚕豆大小紫红色斑片,伴轻微瘙痒,逐渐增多并扩大,累及背部、四肢近端,以四肢屈侧明显。发病前无用药史及化学品接触史,家族中无类似病例。体检:系统检查无异常。皮肤科情况:躯干、四肢近端屈侧密集分布粟粒至蚕豆大的圆形、椭圆形暗灰褐色斑点及斑片,胸背部皮疹长轴与皮纹走行一致,边界较清,皮疹表面光滑,双上臂近端 1 Clinical data Patient, 21 years old. Torso and limbs brown patches more than 2 years. 2 years ago, there was no obvious incentive to appear in the chest several times the size of fava beans purple patches, with a slight itching, and gradually increased and expanded, involving the back, limbs proximal to the limb flexor obvious. Before the onset of drug use history and history of chemical exposure, no similar cases in the family. Physical examination: No abnormality in system examination. Dermatology: trunk, proximal flexor limbs densely distributed miliary to broad bean large round, oval dark gray brown spots and patches, chest and back rash long axis and dermatoglyphics consistent line clearer border rash surface smooth, Double upper arm proximal