Tricophytosis Capitis

This variety is almost wholly confined to childhood and youth - very rarely, if ever, appearing in adult life. The symptom that usually first attracts attention is a small, scaly patch on the scalp, perhaps half an inch in diameter, from which the hair appears to have fallen. On closer examination, however, it is found that, instead of the hairs having fallen, they are broken off a line or two from the surface. If an attempt be made to extract a few of these short stumps with forceps, it will be found that many of them do not come out by the roots, but break off in the follicle, leaving the lower extremity of the root in situ. This fragility of the hairs is a marked feature of the disease, and brings it into contrast with favus, in which affection the hair-shafts are not notably weakened.

If one of the extracted hair-stumps be examined under the microscope, it will be found infiltrated throughout its entire extent with the minute spores of the tricophyton. This fungus, when it takes lodgment on the scalp, gains access to the hair-follicles, into which it descends until it reaches the bottom. Here it increases and invades the root, and travels up the shaft toward the surface. It produces dissociation of the fibres, and thereby weakens the hair. After the surface is reached, there is no outside pressure to counteract the pressure from within the shaft, and the latter gives way and breaks off. The original patch extends centrifugally, and new ones form, so that after a few weeks or months there may be a pretty complete involvement of a considerable portion of the scalp.


In scrofulous subjects, or those prone to suppurative action, the irritation of the fungus may cause the formation of little collections of pus on the substance of the scalp, which, opening on the surface, give a honey-combed appearance to the lesion, to which the older writers assigned the name of kerion.

When left to nature, the affection persists indefinitely, apparently as long as the hairs and hair-follicles afford sufficient pabulum for the fungus. The ultimate termination is baldness. The circular patches on the scalp may spread beyond the line of the hair and down upon the adjacent uncovered skin; and in the form of tricophytosis corporis may appear on other parts of the body.