Superficial Trichophytosis

Superficial trichophytosis is most common among schoolchildren but may be encountered at any age. It is not only a 'school' infection, as it was thought to be previously, but a 'family' infection. That is why preventive measures in this mycosis are conducted both in children's establishments (nurseries, kindergartens, schools) and in the family (home) of the sick child.

Clinical picture and course. Superficial trichophytoses of the scalp, smooth skin, and nails are distinguished.

Superficial trichophytosis of the scalp (Trichophytosis capitis) occurs as microfocal and macrofocal varieties differing from each other only in the size of the foci. There is no acute inflammation, the foci have irregular, unclear boundaries, a spherical shape, and are covered with whitish furfuraceous scales. Vesicles, pustules, and crusts may sometimes be found on the periphery of the foci. Not all the hairs in the focus are involved in the process, it is as if there is thinning of the hair (they become rare). Some are broken off very short ( 1-2 mm from the skin surface) and have the appearance of commas, hooks, question marks and are called stubs. Several foci are usually found on the skin, though in some cases there may only be one small or large focus. The patients have no subjective complaints. Adult males may have superficial trichophytosis of the beard and moustache areas (trichophytosis barbae) the clinical manifestations of which are similar to those of trichophytosis of the scalp.

Superficial trichophytosis of the smooth skin mostly occurs on the face, neck, forearms, and trunk, though it may develop on any other skin areas. The foci are clearly circumscribed and are rather elevated above the skin surface. They are round or oval with a small ridge of a macular or papular character on the periphery on which small vesicles and crusts may form. The centre of the focus is marked by resolution of the pathological process and because of that it is paler in colour and peels. The foci merge and form a quaint pattern. Mild itching may sometimes be felt. The downy hair may be involved in the process, which delays recovery. Trichophytosis of the smooth skin is mostly encountered among children.

Trichophytosis of the nails (trichophytosis unguium). The nail plates (usually the finger-nails) are involved in the process in 2-3 per cent of patients with superficial trichophytosis. The lesion first appears on the free margin of the nail (less frequently on the lunula) and spreads over the whole nail within a few months. The nail plate thickens, becomes loose and crumbles, and acquires a dirty-greyish colour. Subunguinal hyperkeratosis develops. Several nail plates are usually involved. If not treated, the process persists for years.

Chronic Trichophytosis

Etiology. The disease is caused by the same anthropophilic fungi which are responsible for superficial trichophytosis.

Pathogenesis. The disease sets in childhood at first as the superficial form which later acquires the features of chronic (black-dot) trichophytosis in girls; most boys recover spontaneously by the time of puberty. Endocrine disorders, disorders of the vegetative nervous system (acrocyanosis), etc. are important in the pathogenesis of the disease. Females account for 80 per cent of all cases. Adults with chronic trichophytosis account for at least 30 per cent of patients with trichophytosis capitis.

Clinical picture and course. Chronic trichophytosis of the scalp, the smooth skin, and the nails are distinguished.

Chronic trichophytosis of the scalp is mostly localized in the occipital and temporal areas where small pale-reddish lesions with a bluish tinge, diffuse or microfocal scaling, and atrophic bald spots are found. A very characteristic feature is involvement of the hairs, which are broken off on a level with the smooth skin and resemble comedones ( blackheads ). They are so characteristic of chronic trichophytosis of the scalp that the disease itself is often called black-dot trichophytosis.

Chronic trichophytosis of smooth skin differs markedly from the superficial form of the disease in clinical picture, localization, and course. Localization of the foci on the skin of the legs, buttocks, knees and forearms is most typical; less frequently they are found on the face and trunk. The foci have no clear-cut boundaries and are continuous with normal skin. They have a cyanotic bluish colour and are covered with scales on various areas, thus resembling foci of chronic eczema. The persistent and torpid course of chronic trichophytosis of the smooth skin is explained by the anergic immunological state of the body and the simultaneous involvement of the downy hairs in the foci, the scalp and the nails (disseminated affection). Subjective disorders are either absent or are manifested by mild itching. Chronic trichophytosis of the skin on the palms and soles is marked by lamellar scaling of the type of dry dyshidrosis, occurring against the background of hyperkeratosis, with frequent involvement of the nail plates and mild inflammation.

Involvement of the nails is encountered in one third of patients with chronic trichophytosis and is characterized by thickening of the nail plates. They become dirty-greyish and uneven and crumble and break easily. The free nail margin separates from the nail bed.

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