Tinea trichophytina, or ringworm, is a contagious, vegetable-parasitic disease due to the invasion of the cutaneous structures by the vegetable parasite, the trichophyton, or the microsporon Audouinii.
Do the clinical characters of ringworm vary according to the part affected?
Yes, often considerably; thus upon the scalp, upon the general surface, and upon the bearded region, the disease usually presents totally different appearances.
Describe the symptoms of ringworm as it occurs upon non-hairy portions of the body.
Ringworm of the general surface (tinea trichophytina corporis, tinea circinata) appears as one or more small, slightly-elevated, sharply-limited, somewhat scaly, hyperæmic spots, with, rarely, minute papules, vesico-papules, or vesicles, especially at the circumference. The patch spreads in a uniform manner peripherally, is slightly scaly, and tends to clear in the centre, assuming a ring-like appearance. When coming under observation, the patches are usually from one-half to one inch in diameter, the central portion pale or pale red, and the outer portion more or less elevated, hyperæmic and somewhat scaly. As commonly noted one, several or more patches are present. After reaching a certain size they may remain stationary, or in exceptional cases may tend to spontaneous disappearance. At times when close together, several may merge and form a large, irregular, gyrate patch.
Itching, usually slight, may or may not be present.
Exceptionally ringworm appears as a markedly inflammatory pustular circumscribed patch, formerly thought to be a distinct affection and described under the name of conglomerate pustular folliculitis. It consists of a flat carbuncular or kerion-like inflammation, somewhat elevated, and usually a dime to silver dollar in area. The most common seats are the back of the hands and the buttocks. The surface is cribriform, and a purulent secretion may be pressed out from follicular openings.
Fig. 68.
Tinea trichophytina cruris—so-called eczema marginatum—of unusually extensive development. (After Piffard.)