The patient may have been sprayed with tear gas (e.g., Mace) during a riot being dispersed by the police or may have accidentally sprayed oneself. The patient might complain of burning of the eyes, nose, mouth, and skin, as well as tearing and inability to open the eyes because of the severe stinging. There may be sneezing, coughing, runny nose, and perhaps a metallic taste with a burning sensation of the tongue possibly accompanied by nausea, vomiting, and abdominal pain. These signs and symptoms last 15 to 30 minutes after exposure. Redness and edema may be noted for 1 to 2 days after exposure to these aerosol agents.