Definition. A common, contagious, vegetable parasitic disease, appearing on the general body surface, scalp, beard or nails and caused by the microsporon Audouinii or some variety of the trichophyton.
Symptoms. The distribution of the pathological types of ringworm is interesting and it is possible to differentiate them clinically in some cases but the value of such a distinction is slight to the physician whose aim is to cure the disease. Therefore it seems best to consider the varieties or ringworm from a regional standpoint. They are tinea circinate (ringworm of the general surface), tinea tonsurans (ringworm of the scalp), and tinea barbae ringworm of the beard). A description of two inor varieties, tinea cruris seu axillaris (ringworm of the genitocrural and axillary regions) and tinea unguium (ringworm of the nails), will be included after tinea circinata.
Tinea circinata (Trichophytosis corporis; Herpes circinatus; Ringworm of the body). The primary lesion is a pea-sized, pale red, well-defined, slightly- raised maculae which soon becomes scaly and tends to clear in the center as it spreads peripherally, developing a ring-like of annular lesion. The border is generally elevated during evolution, sharply defined and may present papules, vesicles and scales. Before full growth of the lesion is completed, the patch may vary from the size of a coin to an area as large as the palm of the hand. Coalescence of nearby patches may lead to the production of gyrate forms. Frequently, however, the patches do not clear in the center but remain scaly, with or without a well-defined border. Occasionally be border may be pustular or the whole surface may exhibit papules, vesicles or pustules. These variations are hard to recognize except with the aid of the microscope. Itching is usually slight and the patches are usually few in number, often single. The lesions may be limited to one part of the body, often several in the same region, and commonly attack such exposed surfaces as the neck, face and back of hands, without symmetry or order. Tinea circinata may appear alone or in association with the other forms of ringworm.
Tinea cruris seu axillaris (so-called eczema marginatum). When this disease attacks the crural of axillary regions, symmetry of development is often observed. The warmth, moisture and friction of the parts attacked favors the growth of the fungus and its rapid development excites marked itching and irritation and even eczematous inflammation. The patches become large from coalescence and form festooned, elevated, broad, papular or squamous borders enclosing inflamed or pigmented areas. Fresh rings or segments of circles form within the enclosure, while the original border may advance down the lateral chest wall or down the leg to the knee or up to the navel, or onto the perineum buttocks or chest.
Tinea unguium (Onychomycosis: Ringworm of the nails) is rare. The nail becomes opaque, whitish, thickened and brittle. Fortunately only two or three nails are affected but even they run a chronic course and are difficult to cure. For further details see the section on diseases of the nails.
Tinea tonsurans (Trichophytosis capitis; Herpes tonsurans; Prurigo furfurans; Tinea tondens; Ringworm of the scalp) begins as superficial, small, scaly, reddish, round or irregular patch, or if seen early enough may appear as a papular elevation about one, or more hairs. Upon enlargement, vesicles or pustules may appear at the margin but the characteristic appearance is a dime-to silver-dollar-sized patch covered with whitish, branny scales. As the the hairs become infected they lose their luster, become dry, brittle and break off. Often they become so short that they are difficult to find and in fair or fine haired people they are even harder to recognize because they become twisted or matted down with the scales. There is usually more than one lesion and two or more, coalescing, may form irregular or gyrate patches of broad dimensions. The crown and parietal regions are the favorite sites but other forms of ringworm may be present on the adjacent regions of the neck and face. The color of a larger patch may vary from a dirty or blue gray to greenish-yellow, or the early red hue may remain. The broken hairs often have a whitish look from the presence of the fungus and in the course of the disease frequently fall out spontaneously, causing temporary baldness. As the scales fall off or are removed, the hairfollicles have a puckered appearance and rarely an occasional pustules may be found in connection with the remnants of the diseased hair.
The inflammation is deep in the follicle, a pustular folliculitis or kerion exists. This is theoretically the product or mixed infection and is analogous to the process in tinea barbae. It presents a well-defined edematous of fluctuating elevation of the scalp, yellow, red or purplish in color and studded with suppurating points. The lesions may resemble carbuncles and although abscesses may form, they are not as painful prostrating or necrotic as carbuncular formations. If kerion be severe and persistent, permanent baldness will follow. Because of the suppurative process the fungus is often hard to demonstrate. Ringworm of the scalp may take on a disseminated form in which there is a thinning of hair over a considerable area, due no doubt to the diffuse but superficial invasion. A bald tinea tonsurans is a rare variation presenting a circumscribed baldness with a smooth patch similar to alopecia areata. The ringowrm fungus may be found in the stumps of the affected hairs around the border of such a patch. A small degree of itching can be felt in the most ringworms of the scalp, but there is no pain unless suppuration ensues.
Tinea barbae (trichophytosis barbae; Tinea sycosis; Sycosis parasitica; Parasitic sycosis; Herpes tonsurans barbae; Mentagra parasitica; Ringworm of the bread; Barber;’s itch0, Ringworm of the beard usually begins as tinea circinata but its subsequent course varies. If superficial, it may end without inflammation of the hair-follicles. If it pursues a deeper course, the hairs involved become dry, brittle, whitish in color, are easily removed or fall out. Papules or even deeper tender nodular indurations develop varying in size and shape, and of reddish or purplish color. Hair-pierced pustules may be present and if the suppuration is considerable, crusts will form. The degree of suppuration as well as the whole course of the disease varies greatly. The pustular, nodular or eczematous forms may predominate or commingle. While the chin and neck are commonly affected, any portion of the bearded area may be involved with varying degrees of burning, itching and tension. The nodular type is analogous to kerion of the scalp and the suppurating process destroys the hair-follicles, causing permanent loss of hair and scarring. Ringworm of the beard is essentially chronic, frequently relapses, and may last for years if untreated.
Etiology and Pathology. There is no doubt that a certain susceptibility of the skin must preexist in many individuals attacked by ringworm but the exact predisposing causes are uncertain. The disease exists in all countries although more prevalent in some places than in others. Sabouraud claims that an alkaline sweat secretion increases the chance of inoculation. The poorly fed and the well-nourished, the well-to-do and the needy, all are attacked. Age, however, exerts an influence because tinea tonsurans is almost always an affection of childhood and rarely originates after that period: tinea circinata may occur at any age but is rare after middle life; and tinea barbae belongs to the period of manhood and is most common in the early half of adult life. All forms of ringworm are contagious, directly from one person to another or indirectly by clothing, hats, caps, combs, brushes, towels or shaving utensils. Animals subjects to the disease, such as dogs, cats, rabbits, cattle or horses may transmit it to man, and then again, man may inoculate animals. Infections from these domestic animals are apt to the more active, severe and extensive.
The thorough investigations of Sabouraud and others have established the fact that ringworm is caused by two parasitic fungi, the microsporon Audouinii or small-sported fungus, and the trichophyton megalosporon or large-spored fungus. Three forms of the latter are described; endothrix, in the which the spores occur wholly within the hair and which is found, like the microsporon, chiefly in ringworm of the scalp of children, although it may occur in atypical lesions on the face and neck; actothrix, in which the spores are wholly without the hair; and endoectothrix, in which the spores are found both within and without. These last two varieties are derived directly or indirectly from domestic animals and are responsible for most cases of ringworm of the beard and body and for the deep-seated, markedly inflammatory and suppurative types. Sabouraud believes that the microsporon is essentially a human parasite. In tinea circinata the fungus is situated in and under the corneous layer, giving rise to papules, pustules and desquamation. In ringworm of the beard and scalp it usually invades both the epidermis and the hair-follicles. The growth of the parasites in the hair is much more vigorous than in the superficial layer, though found, as a rule, most abundantly in the corneous layer about the hairs when the latter are affected.