Pathologically the first change noted in the epidermis is thought to be an acanthosis, followed by epithelial atrophy, and a hyperkeratosis, intercellular edema, and colloid degeneration of the p.r.i.c.kle cells.

Does the disease bear any resemblance to the miliary papular syphilide, psoriasis, and papular eczema?

In some instances it does, but the irregular and angular outline, the slightly-umbilicated, flattened, smooth or scaly summits, and the dull-red or violaceous color, the history and course, of lichen pla.n.u.s, will serve to differentiate.

State the prognosis.

Under proper management the eruption, although often obstinate, yields to treatment.

What treatment would you prescribe in lichen pla.n.u.s?

A general tonic plan of medication is indicated in most cases, with such remedies as iron, quinine, nux vomica, and cod-liver oil and other nutrients. In many instances a.r.s.enic exerts a special influence, and should always be tried. Mercurials in moderate dosage have also a favorable action in most cases. Locally, antipruritic and stimulating applications, such as are used in the treatment of eczema, are to be employed, alkaline baths and tarry applications deserving special mention. Liquor carbonis detergens, applied weakened with several parts water, is a valuable application. In some cases, particularly if the disease is limited, external applications alone often suffice to bring about a cure.

Pityriasis Rubra Pilaris.

(_Synonyms:_ Lichen Ruber; Lichen Ruber Ac.u.minatus.)

Describe pityriasis rubra pilaris.

Pityriasis rubra pilaris is an extremely rare disease, usually of a mildly inflammatory nature, characterized by grayish, pale-red or reddish-brown follicular papules with somewhat hard or h.o.r.n.y centres; discrete and confluent, and covering a part or the entire surface. The skin is harsh, dry and rough, feeling to the touch somewhat like the surface of a nutmeg-grater or a coa.r.s.e file. More or less scaliness is usually present in the confluent patches and on the palms and soles; in these latter regions the papules are rarely seen. The duration of the disease is variable, and relapses are common. It bears resemblance at times to keratosis pilaris, ichthyosis, dermat.i.tis exfoliativa; it is considered identical with the lichen ruber ac.u.minatus of Kaposi, and by many also with the lichen ruber of Hebra. The etiology is obscure.

Treatment, both const.i.tutional and local, is to be based upon general principles; stimulating applications, with frequent baths, such as are advised in psoriasis, are the most satisfactory. It is rebellious, and not much more than palliation can be effected in some cases, in others the outlook is more hopeful.

Lichen Scrofulosus.

Describe lichen scrofulosus.

Lichen scrofulosus is a chronic, inflammatory disease, characterized by millet-seed-sized, rounded or flat, reddish or yellowish, more or less grouped, desquamating papules. The lesions have their start about the hair-follicles, occur usually upon the trunk, tend to group and form patches, and sooner or later become covered with minute scales. As a rule, there is no itching. It is a rare disease, and but seldom met with in America; it is seen chiefly in children and young people of a scrofulous diathesis. Scarring, slight in character, may or may not follow.

What is the treatment of lichen scrofulosus?

The condition responds to tonics and anti-strumous remedies.

Eczema.

(_Synonym:_ Tetter; Salt Rheum.)

What is eczema?

An acute, subacute or chronic inflammatory disease, characterized in the beginning by the appearance of erythema, papules, vesicles or pustules, or a combination of these lesions, with a variable amount of infiltration and thickening, terminating either in discharge with the formation of crusts, in absorption, or in desquamation, and accompanied by more or less intense itching and a feeling of heat or burning.

What are the several primary types of eczema?

Erythematous, papular, vesicular and pustular; all cases begin as one or more of these types, but not infrequently lose these characters and develop into the common clinical or secondary types--eczema rubrum and eczema squamosum.

[Ill.u.s.tration: Fig. 20. Papular Eczema (leg).]

What other types are met with clinically?

Eczema rubrum, eczema squamosum, eczema fissum, eczema sclerosum and eczema verrucosum. Eczema seborrhoic.u.m is probably a closely allied disease, occupying a middle position between ordinary eczema and seborrh[oe]a.

Describe the symptoms of erythematous eczema.

Erythematous eczema (_eczema erythematosum_) begins as one or more small or large, irregularly outlined hyperaemic macules or patches, with or without slight or marked swelling, and with more or less itching or burning. At first it may be ill-defined, but it tends to spread and its features to become more p.r.o.nounced. It may be limited to a certain region, or it may be more or less general. When fully developed, the skin is harsh and dry, of a mottled, reddish or violaceous color, thickened, infiltrated and usually slightly scaly, with, at times, a tendency toward the formation of oozing areas. Punctate and linear scratch-marks may usually be seen scattered over the affected region.

[Ill.u.s.tration: Fig. 21. Eczema Rubrum.]

Its most common site is the face, but it is not infrequent upon other parts.

What course does erythematous eczema pursue?

It tends to chronicity, continuing as the erythematous form, or the skin may become considerably thickened and markedly scaly, const.i.tuting eczema squamosum; or a moist oozing surface, with more or less crusting, may take its place--eczema rubrum.

Describe the symptoms of papular eczema.

Papular eczema (_eczema papulosum_) is characterized by the appearance, usually in numbers, of discrete, aggregated or closely-crowded, reddish, pin-head-sized ac.u.minated or rounded papules. Vesicles and vesico-papules are often intermingled. The itching is commonly intense, as often attested by the presence of scratch-marks and blood crusts.

[Ill.u.s.tration: Fig. 22. Eczema Squamosum et tissum.]

It is seen most frequently upon the extremities, especially the flexor surfaces.

What course does papular eczema pursue?

The lesions tend, sooner or later, to disappear, but are usually replaced by others, the disease thus persisting for weeks or months; in places where closely crowded, a solid, thickened, scaly sheet of eruption may result--eczema squamosum.

Describe the symptoms of vesicular eczema.

Vesicular eczema (_Eczema vesiculosum_) usually appears, on one or several regions, as more or less diffused inflammatory reddened patches, upon which rapidly develop numerous closely-crowded pin-point to pin-head-sized vesicles, which tend to become confluent and form a solid sheet of eruption. The vesicles soon mature and rupture, the discharge drying to yellowish, honeycomb-like crusts. The oozing is usually more or less continuous, or the disease may decline, the crusts be cast off, to be quickly followed by a new crop of vesicles. In those cases in which the process is markedly acute, considerable swelling and [oe]dema are present. Scattered papules, vesico-papules and pustules may usually be seen upon the involved area or about the border.

The face in infants (_crusta lactea_, or _milk crust_, of older writers), the neck, flexor surfaces and the fingers are its favorite localities.