Kalayciyan Aylin, Aydemir Ertugrul H, Kotogyan Agop
Department of Dermatology, Istanbul University, Cerrahpaşa Medical Faculty, Istanbul, Turkey.
Dermatology. 2007;215(2):114-7. doi: 10.1159/000104261.
The Koebner phenomenon is defined as 'the development of psoriasis at sites of traumatized skin'. The 'all-or-none principle' means that, if psoriasis occurs in one area of injury, all injured areas develop psoriasis or vice versa. The aim is to demonstrate the concordance of patients with the all-or-none principle when a standard method of trauma is employed.
Sixty-two patients with psoriasis were enrolled in the study. Demographic data and disease characteristics were recorded. The medial aspects of both forearms, devoid of lesions, were pricked using two sets of five 30-gauge needles at an angle of 30 degrees , with 2-cm intervals. On days 14 and 28, the patients' forearms were checked for the presence of a typical psoriatic plaque of white scales on an erythematous papule.
On day 28, 45 patients (72.5%) had a negative Koebner response in all prick sites whereas 1 patient (1.6%) had psoriatic papules in 10 out of 10 prick sites. The rest of the patients (n = 16, 25.8%) had between 1 and 9 papules in number.
Using standard methods of trauma, it is possible to induce psoriasis lesions as a Koebner response but this response is not always in concordance with the all-or-none principle previously described.
同形反应被定义为“在创伤皮肤部位出现银屑病”。“全或无原则”是指，如果在一个损伤区域出现银屑病，那么所有损伤区域都会出现银屑病，反之亦然。目的是在采用标准创伤方法时，证明患者是否符合全或无原则。
62例银屑病患者纳入本研究。记录人口统计学数据和疾病特征。使用两组五根30号针头，以30度角、间隔2厘米的方式针刺双侧前臂内侧无皮损处。在第14天和第28天，检查患者前臂是否出现典型的银屑病斑块，即红斑丘疹上有白色鳞屑。
在第28天，45例患者（72.5%）在所有针刺部位的同形反应均为阴性，而1例患者（1.6%）在10个针刺部位中有10个出现银屑病丘疹。其余患者（n = 16，25.8%）出现的丘疹数量在1至9个之间。
使用标准创伤方法，可以诱发银屑病皮损作为同形反应，但这种反应并不总是符合先前描述的全或无原则。
