The possibility of EB infection, initially a strong consideration, has nearly been eliminated by results of serologic tests consistent with a history of an old, but not acute, EB infection.

• EB感染在最初是一个可能性很大的原因，但现在血清学检查结果提示患者以前曾有EB感染而非EB急性感染，所以这个病因几乎可以排除。