Prognosis

As a rule, the simple forms get well, with proper treatment, in two or three weeks. L. circumscriptus and agrius axe often very obstinate.

Lichen appears to be common in those of nervous temperament and in summer time. It attacks all ages, and is evoked by local and reflex irritation, by a deficiency of alkali in the system; irregularities - mental, physical, alimentative, etc.; hereditary tendency, certain occupations, e.g. cooks, bakers, grocers, bricklayers, etc.; hot climates, all seem to be causative factors of this disease.