roughened and pigmented, and present an appearance quite unlike the eruption seen upon the trunk and forearms.
Lichen planus runs a variable course, some cases disappearing spontaneously and often unexpectedly after an existence of a month or two, while others will sometimes persist for many months in spite of the most approved method of treatment. The itching is often very annoying to the patient, but the general health is usually unimpaired, and, unlike lichen ruber, the disease never terminates fatally.
Fig. 53.—Lichen planus.
In the treatment of lichen planus arsenic is often of service, but in this, as in many other affections, it may do harm as well as good; and when there is much irritability of the skin alkaline remedies will be found to be of much greater service. Of the various local remedies which have been highly recommended no one seems to have any special value in all cases. A mild carbolic or salicylic acid lotion may be advantageously used in acute cases, and the same increased in strength when the patches have assumed a chronic character.