Impetigo herpetiformis is an extremely rare disease, observed usually in pregnant women, and is characterized by the appearance of numerous isolated and closely-crowded pin-head-sized superficial pustules, which show a decided disposition to the formation of circular groups or patches. The central portion of these groups dries to crusts, while new pustules appear at the peripheral portion. They tend to coalesce, and in this manner a greater part of the whole surface may, in the course of weeks or months, become involved. Profound constitutional disturbance, usually of a septic character, precedes and accompanies the disease; in almost every instance a fatal termination sooner or later results. It is possibly a grave type of dermatitis herpetiformis. #Ecthyma.# #Give a descriptive definition of ecthyma.# Ecthyma is a disease characterized by the appearance of one, several or more discrete, finger-nail-sized, flat, usually markedly inflammatory pustules. #Describe the symptoms and course of ecthyma.# The lesions begin as small, usually pea-sized, pustules; increase somewhat in area, and when fully developed are dime-sized, or larger, somewhat flat, with a markedly inflammatory base and areola. At first yellowish they soon become, from the admixture of blood, reddish, and dry to brownish crusts, beneath which will be found superficial excoriations. The individual pustules are usually somewhat acute in their course, but new lesions may continue to appear from day to day or week to week. As a rule, not more than five to twenty are present at one time, and in most cases they are seated on the legs. More or less pigmentation, and sometimes superficial scarring, may remain to mark the site of the lesions. Itching is rarely present, but there may be more or less pain and tenderness. #What is the cause of ecthyma?# It is essentially a disease of the poorly cared-for and ill-fed; the direct exciting cause is the introduction of pyogenic microorganisms into the follicular openings. It is closely allied to impetigo contagiosa, and may in fact be regarded as a markedly inflammatory form of the latter affection. It seems much less contagious, however. It is commonly observed in male adults. #From what diseases is ecthyma to be differentiated?# From impetigo contagiosa, and the flat pustular syphiloderm. #How is it distinguished from these several diseases?# The size, shape, inflammatory action, and the depraved general condition, the distribution and lesser-contagiousness will distinguish it from impetigo contagiosa; and the absence of concomitant symptoms of syphilis, and of positive ulceration, as well as its distribution and more rapid and inflammatory course, will exclude the pustular syphiloderm. #State the prognosis.# The disease is readily curable, disappearing upon the removal of the predisposing cause and the employment of local antiseptic applications. #What treatment is to be advised?#