Okuda C, Ito M, Sato Y, Oka K
Department of Dermatology, Niigata University School of Medicine, Japan.
Arch Dermatol Res. 1989;281(4):238-46. doi: 10.1007/BF00431057.
Previously, we reported a morphological change of Trichophyton violaceum in hair tissue in black dot ringworm. To investigate the morphology of Microsporum canis in human hais tissue, three cases of tinea capitis by M. canis were examined by both light and electron microscopy. The fungal elements, which were located deeplyin the keratogenous zone, showed nonseptate hyphae in the outer part of the hair cortex. With the upward development of hair tissues, some hyphae invaded the keratinized inner root sheath and were there transformed into arthrospores, which then occupied the large volume of the inner root sheath; each spore was surrounded by an electron-lucent halo. In some affected hair follicles, at the follicular isthmus level, a microabscess composed of polymorphonuclear leukocytes was often formed in the outer root sheath adjacent to the arthrospores in the keratinized inner root sheath. On the other hand, the remaining hyphae in the cortex became degenerated. Fungi did not invade the hair-germinative cells. There is a distinct relationship between the morphological change of fungi and the differentiation of hair cells in tinea capitis by M. canis as well as in that by T. violaceum, although the direction of invasion and pathological roles of fungal elements within hair tissue are significantly different between the two species of fungi.
此前，我们报道了黑点癣中毛发组织内紫色毛癣菌的形态变化。为了研究犬小孢子菌在人毛发组织中的形态，对3例犬小孢子菌所致头癣病例进行了光镜和电镜检查。真菌成分位于毛发生角质区深部，在毛皮质外层可见无隔菌丝。随着毛发组织向上生长，一些菌丝侵入角化的内根鞘，并在那里转化为关节孢子，随后占据了内根鞘的大部分空间；每个孢子被一个电子透明晕包围。在一些受感染的毛囊中，在毛囊峡部水平，在角化内根鞘中与关节孢子相邻的外根鞘内常形成由多形核白细胞组成的微脓肿。另一方面，皮质中剩余的菌丝发生退化。真菌未侵入毛发芽细胞。犬小孢子菌所致头癣以及紫色毛癣菌所致头癣中，真菌的形态变化与毛发细胞的分化之间存在明显关系，尽管两种真菌在毛发组织内的侵入方向和真菌成分的病理作用有显著差异。
