Which clinical history findings are characteristic of smoke inhalation caused by zinc oxide?

Updated: Oct 15, 2021
  • Author: Keith A Lafferty, MD; Chief Editor: Joe Alcock, MD, MS  more...
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Individuals exposed to HC smoke may complain of nose, throat, and chest irritation. They may experience cough and some nausea. Individuals with severe exposures may present in severe respiratory distress, and such exposures can be fatal. A thorough social history offers vital clues to exposure, since respiratory distress can mimic many different disease processes (see Etiology).

Patients with fume fever typically present in a delayed fashion 4-8 hours after exposure with a pattern of symptoms including dryness of the throat, coughing, substernal chest pain or tightness, and fever. Other symptoms include hoarseness, sore throat, retching, paroxysmal coughing, rapid pulse, malaise, shortness of breath, and abdominal cramps. Respiratory symptoms generally disappear in 1-2 days with supportive care.

Milder exposures are characterized by sensations of dyspnea without any auscultatory, radiologic, or blood gas abnormalities. A patient with moderate exposure to HC may demonstrate rapid clinical improvement within 6 hours. These patients usually are sent home, only to return in 24-36 hours with rapidly worsening dyspnea and dense infiltrative processes on chest radiography. The radiographic abnormalities usually clear, but significant hypoxia may persist during the time the chest radiograph is abnormal.

Prolonged exposures or exposures to very high doses of HC may result in sudden early collapse and death. This may be due to laryngeal edema or glottal spasm. If severe exposure does not kill the individual immediately, hemorrhagic ulceration of the upper airway may occur, with paroxysmal cough and bloody secretions. Death may occur within hours secondary to an acute tracheobronchitis.

Most individuals with HC inhalation injuries progress to complete recovery. Of exposed individuals, 10-20% develop fibrotic pulmonary changes. Distinguishing between those who will recover and those who will not is difficult, since both groups make an early clinical recovery.

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