This rare chronic dermatosis is usually seen upon the dorsal aspect of the hands, especially over the joints. The eruption may appear gradually and slowly or suddenly, and begins as one or more discrete nodules, as a ringed or crescentic group of nodules or a continuous nodular ring. The general appearance of the lesions may be described as smooth, glistening, whitish or ivory-like and apparently semitranslucent. The ring-like formation is solid, deeply in as well as above the surface of the skin, and varies in size from 4 to 2 inches or more in diameter, with an inclosed area of slightly atrophied skin.
Etiology and Pathology. The exact cause is unknown. It frequently first appears in the warm months and afflicts children or young adults of both sexes who have tuberculous antecedents. Histological examinations do not justify the term granuloma, for the process appears to be of deep inflammatory nature, situated around the vessels.
Prognosis and Treatment. This disease, while chronic, is benign in character and will, after a variable period, disappear spontaneously. Salicylic acid, sulphur and resorcin in ointment and lotion have been employed externally. Arsenic and Hydrocotyle may be studied.