Upon the scalp, with eczema and psoriasis; upon the face, with lupus erythematosus and eczema; and upon the trunk, with psoriasis and ringworm.

As a rule, the clinical features of seborrh[oe]a are sufficiently characteristic to prevent error.

What are the differential points?

Eczema, psoriasis, and lupus erythematosus are diseases in which there are distinct _inflammatory symptoms_, such as thickening and infiltration and redness; moreover, psoriasis, and this holds true as to ringworm also, occurs in sharply-defined, circ.u.mscribed patches, and lupus erythematosus has a peculiar violaceous tint and an elevated and marginate border. A microscopic examination of the epidermic sc.r.a.pings would be of crucial value in differentiating from ringworm.

Quite frequently, especially in the interscapular and sternal regions, the segmental configuration const.i.tutes an important feature of seborrh[oe]a--of the eczema seborrhoic.u.m variety.

What is the prognosis in seborrh[oe]a?

Favorable. All types are curable, and when upon the non-hairy regions, usually readily so; upon the scalp it is often obstinate. Relapses are not uncommon.

In those cases of seborrh[oe]a capitis which have been long-continued or neglected, and attended with loss of hair, this loss may be more or less permanent, although ordinarily much can be done to promote a regrowth (see _Treatment of Alopecia_).

How would you treat seborrh[oe]a of the scalp?

By const.i.tutional (if indicated) and local remedies; the former having in view correction or modification of the predisposing factor or factors, and the latter removal of the sebaceous acc.u.mulations and the application of mildly stimulating antiseptic ointments or lotions.

What const.i.tutional remedies are commonly employed?

The various tonics, such as iron, quinine, strychnia, cod-liver oil, a.r.s.enic, the vegetable bitters, laxatives, malt and similar preparations. The line of treatment is to be based upon indications.

How do you free the scalp of the sebaceous acc.u.mulations?

In mild types of the disease shampooing with simple Castile soap (or any other good toilet soap) and hot water will suffice; in those cases in which there is considerable scale-and crust-formation the tincture of green soap (tinct. saponis viridis) is to be employed in place of the toilet soap, and in some of these latter cases it may be necessary to soften the crusts with a previous soaking with olive oil.

The frequency of the shampoo depends upon the conditions. In mild cases once in five or ten days will be sufficiently frequent to keep the parts clean, but in those cases in which there is rapid scale-or crust-production once daily or every second day may at first be demanded.

Name the most effectual applications in seborrh[oe]a capitis.

Sulphur, ammoniated mercury, salicylic acid, resorcin, and carbolic acid.

Sulphur is used in the form of an ointment, from twenty grains to one drachm in the ounce. Ammoniated mercury, in the form of an ointment, ten to sixty grains to the ounce. Salicylic acid, either alone as an ointment, ten to thirty grains to the ounce; or it may often be added with advantage, in the same proportion, to the sulphur or ammoniated mercury ointment above named. Resorcin, either as an ointment, ten to thirty grains to the ounce, or as an alcoholic or aqueous lotion, as the following:--

[Rx] Resorcini ............................ [dram]j-[dram]iss.

Ol. ricini ........................... [minim]x.x.x-f[dram]ij.

Alcoholis ............................ f[Oz]iv. M.

Carbolic acid, to the amount of ten to thirty grains, can be added to this. If an aqueous lotion is desirable, then in the above formula the oleum ricini is replaced with glycerine, and the alcohol with water; three to five minims of glycerine in each ounce is usually sufficient, as a greater quant.i.ty makes the resulting lotion sticky. Petrolatum alone, or with 10 to 30 per cent. lanolin, is usually the most satisfactory base for the ointments. In some cases of the inflammatory variety the skin is found quite irritable, and the mildest applications are at first only admissible.

How are the remedies to be applied?

A small quant.i.ty of the lotion, ointment, or oil is gently applied to the skin; when to the scalp, a lotion or oil can be conveniently applied by means of an eye-dropper. In the beginning of the treatment an application once or twice daily is ordered; later, as the disease becomes less active, once every second or third day.

How is seborrh[oe]a upon other parts to be treated?

In the same general manner as seborrh[oe]a of the scalp, except that the local applications must be somewhat weaker. The several sulphur lotions employed in the treatment of acne (_q. v._) may also be used when the disease is upon these parts. In obstinate patchy cases occasional paintings with a 20 to 50 per cent alcoholic solution of resorcin is curative; following the painting a mild salve should be used.

Comedo.

(_Synonyms:_ Blackheads; Flesh-worms.)

What is comedo?

Comedo is a disorder of the sebaceous glands, characterized by yellowish or blackish pin-point or pin-head-sized puncta or elevations corresponding to the gland-orifices.

At what age and upon what parts are comedones found?

Usually between fifteen and thirty, and upon the face and upper part of the trunk, where they may exist spa.r.s.ely or in great numbers. They are occasionally a.s.sociated with oily seborrh[oe]a, the parts presenting a greasy or soiled appearance.

Exceptionally they occur as distinct, and usually symmetrical, groups upon the forehead or the cheeks. On the upper trunk so-called double and multiple comedo have been noted--the two, three, or even four closely-contiguous blackheads are, beneath the surface, intercommunicable, the dividing duct-walls having apparently disappeared by fusion.

Describe an individual lesion.

It is pin-point to pin-head in size, dark yellowish, and usually with a central blackish point (hence the name _blackheads_). There is scarcely perceptible elevation, unless the amount of retained secretion is excessive. Upon pressure this may be ejected, the small, rounded orifice through which it is expressed giving it a thread-like shape (hence the name _flesh-worms_).

What is the usual course of comedo?

Chronic. The lesions may persist indefinitely or the condition may be somewhat variable. In many instances, either as a result of pressure or in consequence of chemical change in the sebaceous plugs or of the addition of a microbic factor, inflammation is excited and acne results.

The two conditions are, in fact, usually a.s.sociated.

[Ill.u.s.tration: Fig. 8.

Demodex Folliculorum, X 300. Ventral surface. (_After Simon._)]

To what may comedo often be ascribed?

To disorders of digestion, constipation, chlorosis, menstrual disturbance, lack of tone in the muscular fibres of the skin, the infrequent use of soap, and working in a dirty or dusty atmosphere.

A small parasite (_demodex folliculorum_, _acarus folliculorum_) is sometimes found in the sebaceous ma.s.s, but its presence is without etiological significance, as it is also found in healthy follicles. A microbacillus has been found by several observers, and credited with etiological influence.

What is the pathology of comedo?