Metal fume fever is an occupational disease caused by inhalation of metal-containing fumes, most important element being zinc oxide. The clinical presentation comprises of constitutional symptoms developing within several hours after exposure, and in most cases, spontaneous resolution after cessation of exposure is observed. The diagnosis is based on clinical criteria and confirmation of occupational exposure.
Metal fume fever (MFF) has been recognized in the past few centuries as an important occupational disorder in the brass and welding industries (particularly in galvanized steel production), and between 1,500-2,000 workers suffer from this condition in the United States on an annual basis    . Inhalation of zinc oxide (ZnO), the principal causative agent of MFF, but also iron and copper oxide in the work setting is considered to be toxic and results in the production of various symptoms    . The clinical presentation is distinguished by the onset of a dry cough, dyspnea, fever, chills, headaches, myalgias, fatigue, malaise, and arthralgias within 3-12 hours after exposure to metal-containing fumes    . In addition, a metallic taste in the mouth, a dry throat, and excessive salivation have been reported as potential symptoms as well  . Complaints usually resolve after 24 hours, but they can persist throughout the initial week and completely disappear by the beginning of the next week   . The marked improvement of symptoms over the weekend, when workers are removed from the source of exposure, is often referred to as tachyphylaxis, which is not uncommon for metal fume fever    . The condition is self-limiting and rarely poses a significant risk for the patient, but reports have documented the development of pericarditis, pneumonitis and even aseptic meningitis in individuals who were exposed to very high amounts of metal fumes   . Furthermore, studies have implicated a potential link between occupational asthma and metal fume fever, with further research needed to confirm these claims .
Recognition of metal fume fever may significantly improve the quality of the patient's life and a comprehensive workup is necessary in order to make the diagnosis. A detailed patient history is perhaps the single most important component of the workup, as identification of the patient's occupancy, exact job description, and confirmation regarding the substances and risks the patient is exposed to is vital in raising clinical suspicion toward MFF   . Furthermore, the rapid onset and resolution of symptoms can point to an occupational disease. A complete physical examination that will document all typical signs and symptoms should follow, after which several laboratory studies may be performed. As many patients will have a high leukocyte count and an elevated erythrocyte sedimentation rate (ESR), a complete blood count (CBC) and evaluation of serum inflammatory markers are recommended tests   . In addition, serum and urine levels of zinc are often elevated . If an occupational etiology is suspected in patients with constitutional symptoms, plain radiography of the chest is mandatory, and normal findings are observed in most cases, but a diffuse patchy infiltration is seen in severe cases . Because direct tests to confirm MFF do not exist, the physician must gather all the necessary information through history taking, physical examination and laboratory studies and make the diagnosis based on his/her clinical judgment  .