Definition And Description

The first clear and distinct description of this affection was given by Wilson (135, 3: 117) in the following language:

"Lichen planus is an eruption of pimples remarkable for their color, their figure, their structure, their habits of isolated and aggregated development, their habitat, their local and chronic character, and for the melasmic stains which they leave behind them when they disappear.

The color of the pimples is a dull crimson-red, more or less vivid, and suffused with a purplish or lilac tinge.

"In figure the papula; are flattened, smooth, and depressed on the summit, angular in outline, only slightly elevated, and of a size varying between one and three lines in diameter; .... the flatness is rendered more conspicuous by the summit of the papule being occupied by a thin, horny, semi-transparent lamina of cuticle, depressed on the surface, and marked in the centre by the aperture of a follicle which represents a sort of hilum.....

In structure the papule of Lichen planus is a hyperaemia with exudation, surrounding a follicle, and covered by a thin layer of horny, transparent cuticle; while the aperture of the follicle and its conical epidermic plug are visible in the centre of the horny plate. The horny covering is in nowise a scale; it rises and falls with the papule, and neither separates nor exfoliates.....

"Lichen planus presents two principal forms of manifestation, discrete and aggregate.....

"The habitat of the eruption is also characteristic of the identity of Lichen planus; it is pretty constantly met with on the front of the forearm, just above the wrist; in the hollow of the loins; on the lower half of the abdomen; on the hips; around the knees; particularly over the mass of the vastus internus muscle; on the forearms and calves of the legs, and in women, around the waist, and in the grooves occasioned by the garters. We have seen it also, but less frequently, on the palms of the hands and soles of the feet; and in two instances on the tongue, the buccal membrane, and the mucous lining of the fauces.

"Lichen planus is essentially chronic and local in its habits.....

In distribution it is generally symmetrical, but occasionally is limited to one side of the body; sometimes occurring on one side in the upper extremity, and on the other in the lower. It has no constitutional symptoms of its own, and frequently prevails with very little disturbance of any kind." The affection is sometimes attended with slight, rarely with severe itching, and occurs most frequently during the middle periods of life.

Diagnosis

The only affection with which Lichen planus is likely to be confounded is a papular syphilide. The resemblance, on a cursory examination, is often so striking, that a careful study of the peculiar lesions above mentioned will be rendered necessary. The pruritus which is usually present in Lichen planus serves also to distinguish it from a syphilide. The previous history must also be taken into account.

Prognosis

The prognosis of Lichen planus is good, the majority of cases recovering under a few months' treatment.

Etiology

Little, if anything, is known on the subject.

Treatment

Wilson, who has probably had a larger experience with the disease than any other dermatologist, says: "Our first object should be to regulate the functions of the economy whenever any disorder may be apparent; in the next place we should endeavor to restore the vigor of the system by tonic remedies, such as bitters, quiuine, nitro-muriaticacid, and chalybeates; and these objects being effected we may finally have recourse to the tonic - nutritive operation of arsenic." Locally, he recommends a lotion of the bichloride of mercury, two grains to the ounce of bitter almond emulsion.

T. Fox (61, 150) considers that there are four general indications for treatment: "The first is to improve the tone of the patient as regards his nervous system by proper rest and quiet, by change of air and scene, and the avoidance of fatigue, if necessary. The cure is not solely a matter of mere dosing the patient. The general tonics appropriate to the disease are quinine, cod-liver oil, the mineral acids, and perchloride of iron.

"The second indication is to alleviate internal troubles - of stomach especially - and it is necessary to do this before beginning a tonic treatment.....

"The third indication is to feed up the patient whenever there is evidence that his or her living has been bad or defective; but in order to do this it is necessary that such conditions as dyspepsia, pyrosis, or the like, be first of all removed.

"The fourth indication is to attempt to diminish the hyperaemia by astringents given internally, e.g., the perchloride of iron. But this cannot be undertaken till special influences that intensify the irritation of the skin, dyspepsia, etc., are properly negatived. I like the perchloride of iron in full doses in cases of lichen planus. With regard to arsenic I can only say that it has always made my cases worse. In some instances of lichen planus in the discrete form, where the papules have been particularly solid and there has been less hyperaemia than usual, and the patient was fairly strong, I have given alterative doses of mercurials with very great benefit indeed, in conjunction with cod-liver oil." Fox also uses internally, as anti-pruritics, aconite, chloral, carbolic acid and opiates; and externally alkaline baths, oxide of zinc, subnitrate of bismuth, oil of cade, etc.

Taylor (110, Oct., '74) reports good results from the use of oxidizing agents and alkaline diuretics.

In my own experience, which has been limited to the treatment of some six or seven cases only, the principles of treatment laid down by Wilson, have been followed with satisfactory results.