A decided rigor or a feeling of chilliness followed by febrile action usually ushers in the cutaneous disturbance. The skin at a certain point or part, commonly where there is a lesion of continuity, becomes bright red and swollen; this spreads by peripheral extension, and in the course of several hours involves a portion or the whole region. The parts are shining red, swollen, of an elevated temperature, and sharply defined against the sound skin. After several days or a week, during which time there is usually continued mild or severe febrile action, the process begins to subside, and is followed by epidermic desquamation. In some cases vesicles and blebs may be present; in other cases the disease seriously involves the deeper parts, and is accompanied by grave constitutional symptoms. In exceptional instances sloughing takes place. A mild, transitory, limited, and often recurrent erysipelatous condition of the outlet and immediate neighborhood of one or both nostrils is met with, taking its origin from an inflammation of the hair-follicles just inside the margin of the nose; constitutional symptoms are usually wanting. Somewhat similar, doubtless, is the erysipelatous inflammation (_erysipeloid_) observed on the fingers and hands of butchers, etc., starting from a wound, apparently as a result of infection from putrid meat or fish. #What is erysipelas migrans (or erysipelas ambulans)?# A variety of erysipelas which, after a few hours or days, disappears at one region and appears at another, and so continues for one or several weeks. #What is the cause of erysipelas?# The disease is due to a specific streptococcus--the streptococcus of Fehleisen. Depression of the vital forces and local abrasions are predisposing factors. #State the diagnostic points.# The character of the onset, the shining redness and swelling, the sharply-defined border, and the accompanying febrile disturbance. #What is the prognosis in erysipelas?# In most instances the disease runs a favorable course, terminating in recovery in one to three weeks. Exceptionally, in severe cases, a fatal termination ensues. #What is the treatment of erysipelas?# _Internally_, a purge, followed by the tincture of the chloride of iron and quinia, and stimulants if needed. _Locally_, one to three per cent. carbolic-acid lotion or ointment, a saturated solution of boric acid, or a ten- to twenty-per-cent. aqueous solution or ointment of ichthyol may be employed. In some cases the spread of the disease is apparently controlled by painting the bordering healthy skin with a ring of tincture of iodine or strong solution of nitrate of silver. #Phlegmona Diffusa.# #What do you understand by phlegmona diffusa?#