Describe the symptoms of ringworm when occurring about the thighs and s.c.r.o.t.u.m.

In adults, more especially males, the inner portion of the upper part of the thighs and s.c.r.o.t.u.m (_tinea trichophytina cruris_, so-called _eczema marginatum_) may be attacked, and here the affection, favored by heat and moisture, develops rapidly and may soon lose its ordinary clinical appearances, the inflammatory symptoms becoming especially prominent.

The whole of this region may become involved, presenting all the symptoms of a true eczema; the border, however, is sharply defined, and usually one or more outlying patches of the ordinary clinical type of the disease may be seen.

Describe the symptoms of ringworm when involving the nails.

In ringworm of the nails (_tinea trichophytina unguium_) these structures become soft or brittle, yellowish, opaque and thickened the changes taking place mainly about the free borders. Ringworm on other parts usually coexists.

Describe the symptoms of ringworm as it occurs upon the scalp.

Ringworm of the scalp (_tinea trichophytina capitis_, _tinea tonsurans_) begins usually in the same manner as that upon the general surface, but, as a rule, much more insidiously. Sooner or later, however, the hair and follicles are invaded by the fungus, and in consequence the hair falls out or becomes brittle and breaks off. The follicles, except in long-standing cases, are slightly elevated and prominent, and the patch may have a puffed or goose-flesh appearance. In addition, there is slight scaliness.

Describe the appearances of a typical patch of ringworm of the scalp.

The patch is rounded, grayish, somewhat scaly, and slightly elevated; the follicles are somewhat prominent; there is more or less alopecia, with here and there broken, gnawed-off-looking hairs, some of which may be broken off just at the outlet of the follicles and more or less surrounded by a whitish or grayish-white dust. This type is produced by the small-spore fungus--microsporon.

Does ringworm of the scalp always present typical appearances?

Not invariably. In some cases the patch or patches may become almost completely bald, and in others a tendency to the formation of pustules, with more or less crust-formation, may be seen. The affection may also appear as small scattered spots or points.

[Ill.u.s.tration: Fig. 69.

Ringworm (rather inflammatory type, and produced by the trichophyton).]

The markedly inflammatory and pustular types are produced by the large-spore fungus--trichophyton.

What is tinea kerion?

Tinea kerion (_kerion_) is a markedly inflammatory type of ringworm of the scalp involving the deeper tissues, appearing as a more or less bald, rounded, inflammatory, [oe]dematous, boggy, honeycombed tumor, discharging from the follicular openings a mucoid secretion.

Does ringworm of the scalp ever occur in adults?

No. (Extremely rare exceptions.)

[Ill.u.s.tration: Fig. 70.

Ringworm Fungus (Trichophyton) x 450. (_After Duhring._) As found in epidermic sc.r.a.pings of ringworm, showing mycelium and spores.]

Describe the symptoms of ringworm of the bearded region.

Ringworm of the bearded region (_tinea trichophytina barbae_, _tinea sycosis_, _parasitic sycosis_, _barber's itch_) begins usually in the same manner as ringworm on other parts, as one or more rounded, slightly scaly, hyperaemic patches. In rare instances the disease may persist as such, with very little tendency to involve the hairs and follicles; but, as a rule, the hairy structures are soon invaded, many of the hairs breaking off, and many falling out. From involvement of the follicles, more or less subcutaneous swelling ensues, the parts a.s.suming a distinctly _lumpy and nodular_ condition. The skin is usually considerably reddened, often having a glossy appearance, and studded with few or numerous pustules. The nodules tend, ordinarily, to break down and discharge, at one or more of the follicular openings, a glairy, glutinous, purulent material, which may dry to thick, adherent crusts.

[Ill.u.s.tration: Fig. 71.

Ringworm Fungus (Microsporon) x 500. (_After Duhring._) Short, broken-off hair of scalp invaded with ma.s.ses of free spores.]

The disease may be limited to one patch, or a large area, even to the extent of the whole bearded region, becomes involved. The upper lip is rarely invaded. Ringworm of the bearded region is due to the trichophyton.

[Ill.u.s.tration: Fig. 72.

Ringworm Fungus (Trichophyton) x 300. (_After Duhring._) Short, stout hair of beard, with the root-sheath attached, showing free spores and chains of spores.]

To what is ringworm due?

To the presence and growth in the cutaneous structures of a vegetable parasite. Although the disease is contagious, individuals differ considerably as to susceptibility. It is much more common in children than in those past the age of p.u.b.erty, ringworm of the scalp being limited to the former (rare exceptions), and tinea sycosis being a disease of the male adult.

Until recently the ringworm was thought to be due to but one fungus--the trichophyton; it is now known that there are several forms of fungi, the main forms being the small-spored (microsporon Audouini) and the large-spored (trichophyton). Of this latter there are two main subvarieties--endothrix and ectothrix. The small-spored fungus is found as the cause in the majority of scalp cases; the endothrix also commonly invades the scalp integument. The ectothrix variety is usually derived directly or indirectly from domestic animals, and is chiefly responsible for body-ringworm, and for suppurative ringworm, whether upon the bearded region or elsewhere.

What is the pathology of ringworm?

On the general surface the fungus has its seat in the epidermis, especially in the corneous layer; upon the scalp and bearded region the epidermis, hair-shaft, root and follicle are invaded. The inflammatory action may vary considerably in different cases, and at different times in the same case.

The fungus consists of mycelium and spores. In the epidermic sc.r.a.pings it is never to be found in abundance, and the mycelium predominates, while in affected hairs the spores and chains of spores are almost exclusively seen, and are usually present in great profusion.

How do you examine for the fungus?

The sc.r.a.pings or hair should be moistened with liquor pota.s.sae, and examined with a power from three hundred diameters upward.

How is ringworm of the general surface to be distinguished from eczema, psoriasis and seborrh[oe]a?

By the growth and characters of the patch, the slight scaliness, the tendency to disappear in the centre, by the history, and, if necessary, by a microscopic examination of the scales.

How is ringworm of the scalp to be distinguished from alopecia areata, favus, eczema, seborrh[oe]a, and psoriasis?

By the peculiar clinical features of ringworm on this region--the slight scaliness, broken hair and hair stumps, with a certain amount of baldness--and in doubtful cases by a microscopical examination of the hairs.

In favus, although the same condition of the hair is noted, the yellow, cup-shaped crusts, and the presence of the atrophic areas in that disease are pathognomonic.

How is ringworm of the bearded region to be distinguished from eczema and sycosis?

By the peculiar lumpiness of the parts, the brittleness of the hair, more or less hair loss, and the history.

The superficial type of ringworm sycosis--those cases in which the disease remains a surface disease--is readily distinguished, as the symptoms are essentially the same as ringworm of non-hairy parts, except that some of the hairs in the areas may become invaded and break off or fall out.

In doubtful cases recourse may be had to microscopical examination.

What is the prognosis of ringworm of these several parts?