The _small flat-pustular syphiloderm_ (_impetigo-form syphiloderm_) consists of a more or less generalized, pea-sized, flat or raised, discrete, irregularly-grouped, or in places confluent, pustules, appearing usually in the first year of the disease. The pustules dry rapidly to yellow, greenish-yellow, or brownish, more or less adherent, thick, uneven, somewhat granular crusts, beneath which there may be superficial or deep ulceration; where the lesions are confluent a continuous sheet of crusting forms. The eruption is often scanty. It is most frequently observed about the nose, mouth, hairy parts of the face and scalp, and about the genitalia, frequently in association with papules on other parts. #Are you likely to mistake the small flat-pustular syphiloderm for any other eruption?# Scarcely; but when upon the scalp, it may bear rough resemblance to pustular eczema, but the erosion or ulceration will serve to differentiate. Moreover, concomitant symptoms of syphilis are to be looked for. #Describe the large flat-pustular eruption of syphilis.# The _large flat-pustular syphiloderm_ (_ecthyma-form syphiloderm_) consists of a more or less generalized, scattered eruption, of large pea- or dime-sized, flat pustules. They dry rapidly to crusts. The bases of the lesions are a deep-red or copper color. Two types of the eruption are met with. In one type--the superficial variety--the crust is flat, rounded or ovalish, of a yellowish-brown or dark-brown color, and seated upon a superficial erosion or ulcer. The lesions are usually numerous, and most abundant on the back, shoulders and extremities. It appears, as a rule, within the first year, and generally runs a benign course. [Illustration: Fig. 55. Rupia. (_After Tilbury Fox._)] In the other type--the deep variety--the crust is greenish or blackish, is raised and more bulky, often conical and stratified, like an oyster shell--_rupia_; beneath the crusts may be seen rounded or irregular-shaped ulcers, having a greenish-yellow, puriform secretion. It is usually a late and malignant manifestation. #How would you differentiate the large flat-pustular syphiloderm from ecthyma?# The syphilitic lesions are more numerous, are scattered, are attended with superficial or deep ulceration, and followed by more or less scar-formation. Moreover, the history, and presence or absence of other symptoms of syphilis have an important diagnostic value. [Illustration: Fig. 56. Ulcerating Tubercular Syphiloderm.] #Describe the bullous eruption of syphilis.#