In acute cases of supraglottic and epiglottic oedema the suffocative paroxysms may last several minutes, and recur at irregular intervals of a few hours with increased intensity. If not relieved, patients become wildly excited or terror-stricken; they may throw the chest forward, open the mouth, grasp the throat outside or thrust their hands into it, and make convulsive movements in their struggles for breath; with protruding eyes and flushed face they become cyanotic, the extremities cold, the pulse small and frequent; coma supervenes, and death. In chronic cases the symptoms are not so violent, though they may steadily progress to impending strangulation, but for a long time the dysphagia gives the patient much more distress than the dyspnoea. In circumscribed acute cases leading to the formation of an abscess there is usually pain in a particular spot, and often general feverishness, in addition to all the symptoms before mentioned, according to the seat of the oedema. Sometimes the suffering in laryngeal abscess at its height is very intense. Perforation into the pharynx, oesophagus, or even externally, may take place, but usually the pus points into the larynx. When the pus is evacuated either spontaneously or by incision, violent choking, coughing, and hawking may occur, but after it is evacuated all dangerous symptoms usually rapidly subside. In sanguineous infiltration the symptoms do not differ from serous or purulent oedema under the same circumstances. Hemorrhagic infusion is usually {115} sudden, and the resulting stenosis often fatal. Muscular spasm or paralysis sometimes coexists with laryngeal oedema, and greatly adds to the interference with respiration.