Name the several varieties met with.

Three varieties are presented, named according to the parts involved, pediculosis capitis, pediculosis corporis, and pediculosis pubis; the parasite in each being a distinct species of pediculus.

Pediculosis Capitis.

Describe the symptoms of pediculosis capitis.

Pediculosis capitis (_pediculosis capillitii_), due to the presence of the pediculus capitis, occurs much more frequently in children than in adults. It is characterized by marked itching, and the formation of various inflammatory lesions, such as papules, pustules and excoriations--resulting from the irritation produced by the parasites and from the scratching to which the intense pruritus gives rise. In fact, an eczematous eruption of the pustular type soon results, attended with more or less crust formation. In consequence of the cutaneous irritation the neighboring lymphatic glands may become inflamed and swollen, and in rare cases suppurate. The occipital region is the part which is usually most profusely infested, more especially in young girls and women. In those of delicate skin, especially in children, scattered papules, vesico-papules, pustules, and excoriations may often be seen upon the forehead and neck. In some instances, however, especially in boys, there may be many pediculi present, with but little cutaneous disturbance, the itching being the sole symptom.

[Ill.u.s.tration: Fig. 79.

Pediculus Capitis x 25. (_After Duhring._) Female. Dorsal surface.]

In addition to the pediculi, which, as a rule, may be readily found, their _ova_, or _nits_, are always to be seen upon the shaft of the hairs, quite firmly attached.

Describe the appearance of the ova.

They are dirty-white or grayish looking, minute, pear-shaped bodies, visible to the naked eye, and fastened upon the shaft of the hairs with the small end toward the root.

[Ill.u.s.tration: Fig. 80.

Ova of the head-louse attached to a hair. Magnified. (_After Kaposi._)]

Is there any difficulty in the diagnosis of pediculosis capitis?

No. The diagnosis is readily made, as the pediculi are usually to be found without difficulty, and even when they exist in small numbers and are not readily discovered, _the presence of the ova_ will indicate the nature of the affection.

Pustular eruptions upon the scalp, especially posteriorly, should always arouse a suspicion of pediculosis. The possibility of the pediculosis being secondary to eczema must not be forgotten.

What is the treatment of pediculosis capitis?

Treatment consists in the application of some remedy destructive to the pediculi and their ova. Crude petroleum is effective, one or two thorough applications over night being usually sufficient; in order to lessen its inflammability, and also to mask its somewhat disagreeable odor, it may be mixed with an equal part of olive oil and a small quant.i.ty of balsam of Peru added.

Tincture of cocculus indicus, pure or diluted, may also be applied with good results.

When the parts are markedly eczematous, an ointment of ammoniated mercury or [beta]-naphthol, thirty to sixty grains to the ounce may be used.

Daily shampooing with soap and water, and the twice daily application of a five per cent. carbolic acid lotion, together with the use of a fine-toothed comb, is a safe and efficient method for dispensary practice; as it is, indeed, for any cla.s.s of patients.

How are the ova or their sh.e.l.ls to be removed from the hair?

By the frequent use of acid or alkaline lotions, such as dilute acetic acid and vinegar, or solutions of sodium carbonate and borax.

Pediculosis Corporis.

Describe the symptoms of pediculosis corporis.

Pediculosis corporis is dependent upon the presence of the pediculus corporis (_pediculus vestimenti_), a larger variety than that infesting the scalp. It is characterized by more or less general itching, together with various inflammatory lesions and excoriations. As the parasites are to be found chiefly in the folds and seams of the clothing, visiting the skin for the purpose of feeding, the various symptoms--the minute hemorrhagic puncta showing the points at which they have been sucking, and the consequent papules, pustules and excoriations--are, therefore, to be found most abundantly on those parts with which the clothing comes closely in contact, as, for instance, around the neck, across the shoulders, around the waist, and down the outside of the thighs. It is uncommon in children.

[Ill.u.s.tration: Fig. 81.

Pediculus Corporis x 25. (_After Duhring._) Female. Dorsal surface.]

State the diagnostic characters of pediculosis corporis.

The presence of the minute hemorrhagic puncta, the multiform character and peculiar distribution of the eruption. Careful search will almost invariably disclose one or more pediculi.

What is the treatment of pediculosis corporis?

The clothing and bed-coverings are to be thoroughly baked or boiled, the pediculi and their ova being in this manner destroyed; a thymol or carbolized boric-acid lotion may be used to relieve the cutaneous irritation.

When attention to the wearing apparel is not immediately practicable, ointments of sulphur and staphisagria, and lotions of carbolic acid, may be advised as temporary measures. The wearing of a bag of loosely woven texture containing some lump sulphur next to the skin is useful in such cases; at the temperature of the body the sulphur undergoes slow oxidation. In hairy individuals the malady is often persistent, due to the fact that ova have become attached to the hair and a new progeny soon hatched out. Continued treatment over a few weeks will usually suffice to rid the patient of their presence.

Pediculosis Pubis.

Describe the symptoms of pediculosis pubis.

Pediculosis pubis is a condition due to the presence of the pediculus pubis, or crab-louse. It is characterized by more or less itching about the genitalia, together with papules, excoriations, and other inflammatory lesions. The amount of irritation varies; it may be slight, or, on the other hand, severe. The parasite, which is the smallest of the three varieties, may be discovered upon close examination seated near the roots of the hairs, clutching the hair, with its head downward and buried in the follicle. The ova may be seen attached to the hair-shafts.

It infests adults chiefly, being in many instances probably contracted through s.e.xual intercourse.

Is the pediculus pubis found upon any other part of the body?

Yes. Although its favorite habitat is the region of the p.u.b.es, it may, in exceptional instances, also infest the axillae, the sternal region of the male, the beard, eyebrows, and even the eyelashes.

State the diagnostic characters of pediculosis pubis.

The region involved, itching, variable amount of irritation, and, above all, the presence of the pediculi and their ova.

[Ill.u.s.tration: Fig. 82.

Pediculus Pubis x 25. (_After Duhring._) Female. Dorsal surface.]

Name several applications prescribed for pediculosis pubis.