metal fume fever
- related: Occupational Lung Disease
- tags: #literature #boards
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- cause: exposure to zinc oxide from working with metal
- sx: flu like illness, starts several hours after exposure and resolves in 1-2 days
- more likely to happen after period away from job
The patient in this case has a history and symptoms most consistent with metal fume fever. Therefore, the treatment is supportive care, such as use of over-the-counter analgesics for symptom relief, removal from the exposure temporarily, and ensuring appropriate use of engineering controls such as local exhaust ventilation, along with correct use of personal protective equipment (choice B is correct).
Metal fume fever involves inhalation of metal oxides produced from the welding process, particularly with the inhalation of zinc oxide. The inhalation of these fumes may provoke a number of clinical responses characterized by a self-limiting illness composed of symptoms such as fever, cough, wheezing, chest tightness, fatigue, chills, fever, myalgias, cough, dyspnea, and occasionally a leukocytosis with a left shift. Thirst, a metallic taste, and excess salivation have also been reported. The diagnosis is based on clinical findings and an occupational history that includes cutting or annealing galvanized steel or similar metals resulting in release of oxides that stimulate a cytokine response. The symptoms typically resolve spontaneously, but over-the-counter analgesics such as acetaminophen or ibuprofen may be used for symptom relief. Without persistent exposure to these fumes, no chronic pulmonary conditions ensue; however, it is critical that individuals working in environments with these exposures use personal protective equipment correctly and that exhaust ventilation is working as designed.
In this case, there is no indication to obtain further testing such as a urine collection for zinc or heavy metals (choice A is incorrect). After obtaining a detailed work history, which would lead to the diagnosis, there is no need for additional imaging such as a chest radiograph or CT imaging of the thorax, since it is not expected to reveal any clinically significant abnormalities acutely (choice C is incorrect). Although upper airway irritation associated with chest tightness and cough may represent work-related asthma, the presence of fever and flu-like symptoms would not be characteristic of asthma; therefore, in light of his exposure history to galvanized metals, exhaled nitric oxide testing also would not be necessary (choice D is incorrect).
A similar clinical process is referred to as polymer fume fever, which involves overheating of polytetrafluoroethylene, which also occurs as a self-limited systemic illness with only minor pulmonary symptoms. Like metal fume fever, constitutional signs and symptoms typically present several hours after initial exposure. Compared with metal fume fever, polymer fume fever involves more varied clinical presentations, the severity of which depends on the specific conditions of exposure. When higher temperatures and/or longer durations of exposure with poor ventilation are involved, significant pulmonary involvement, such as consolidation of the pulmonary parenchyma on radiographic imaging, may be noted. Although a number of industrial outbreaks have implicated the smoking of contaminated cigarettes as a vehicle of exposure, household activity in which nonstick cookware is severely overheated has been reported. In these cases, cookware coatings may not reveal significant decomposition unless temperatures exceed about 660°F (349°C), making empty cookware inadvertently left on heating elements a potential source of these fumes without visual clues if not suspected.1