LICHEN.
Lichen urticalus being a variety of urticaria, its treatment will be that of the primary type of disease. L. simplex being but the papuhir stage of impetigo or eczema, and L. circuhnscri plus, L. circinatus, or L. serpiginosus being a variety of seborrhoea, these conditions yield to the remedies indicated by the underlying affection. L. pilaris is a variety of keratosis affecting the upper part of the follicles, and L. spinulosus is almost cer tainly of the same nature, and will yield to the treatment detailed under Keratosis and Ichthyosis. L. tropicus is prickly heat or miliaria rubra allied to strophulus or red gum, the treatment of which will be detailed under their own headings. L. luenurrrhagicus and L. lividus are the result of minute hemorrhages into the region of the hair follicles which yield to the remedies indicated by the blood condition—viz., purpura. There remain after the elimination of the above two cutaneous affections to which the name Lichen should be restricted—viz., L. planus and L. scrofulosoruni.
The treatment of L. planus is always tedious and often unsatisfactory; improved hygiene, regular hours of work, rest and sleep and dieting must be insisted upon. Mental overwork and a neurotic strain being found in a considerable percentage of cases, it is obvious that the intense pruritus must be relieved at night, otherwise a severe form of insomnia develops.
Internal treatment should never be omitted. Arsenic holds the first place as in the treatment of psoriasis, and it must be given in full doses for some months, with periodical breaks in the course of about a fortnight each, In acute cases Tartarised Antimony should be administered, and when this agent fails in making a distinct impression upon the eruption of flattened purplish-red papules Mercury in the form of gr. doses of the perchloride or biniodide should be tried, but salivation must be avoided. Phosphorus has also some power, but its best effects may be procured by doses given in the intervals during which arsenic is being suspended.
Local treatment consists in Alkaline Baths and the use of Tar prepara tions to relieve the severe itching. When the eruption is extensive the best application is one like the following: B. Liq. Carb. Detergens Liq. Plumbi Fort. 3ij.
Apo Destillatce 3xx. Misce.
By substituting Bicarbonate of Sodium for the lead in the above the lotion may be freely employed for long periods without the possibility of harm.
Chronic cases require stronger preparations, and the formula, for tarry ointments are numberless; one of the best is that found so suitable in scaly eczema, consisting of 3 drs. of Liq. Carb. Deterg., zo grs. Hyd. Ammon. Chlor., and 2 oz. Lanolin. Unna prefers Carbolic Acid to tar, and his lichen ointment consists of 3o mins. Carbolic Acid, 4 grs. Corrosive Sublimate, and 2 oz. Zinc Ointment, the different ingredients being increased or diminished according to the requirements of each case. Thus for an old but small indurated patch he has increased the perchloride to the strength of to or even 20 grs. per oz.
Salicylic Acid Ointment, i part to zo of lard, may be applied in chronic cases, and Pyrogallic Acid or Chrysarobin can be used of the same strength when the lesion is limited in extent and of long standing. A good effect in the latter class of case may be obtained by covering the indurated patch with Soft Soap or with Emp. Hydrargyri or Emp. Salicylici. Some dermatologists do not hesitate to destroy small horny areas with the galvano-cautery. X rays have proved most valuable in the treatment of old indurated patches, and are more efficacious than the cautery.
Sometimes relief to the itching follows in a surprising manner. Trichlor acetic Acid may be applied to small patches after thorough cleansing of the skin; Vaccine treatment is usually of no value. Some rare acute forms of lichen, in which the papules are sharp-pointed from involvement of the hair follicle as in Hebra's Lichen ruber acmninatus and Unna's L. nettraticus , are liable to end fatally, and should only be treated by sooth ing applications of Olive or Carron Oil. Some chronic neurotic types only respond to hydropathic treatment by Jacquet's method of forcibly projecting a douche of warm water (98° F.) against the skin on each side of the spine, followed up by a dash of cold water, and Fordyce has obtained good results from a course of sea-water baths. L. scrofuloserum is believed to be always of tuberculous nature. The internal administration of Cod Liver Oil, Creosote and Iodide of Iron with Arsenic should be combined with local applications of Salicylic Acid Ointment, 2 to 5 per cent., or Creosote Ointment (B.P.), and if these fail the X rays may be employed.