Symptoms of humidifier fever are “flu-like,” lethargy, arthralgia (neuralgic pain in the joints), myalgia and fever. Sometimes headaches, polyuria (excessive urination) and weight loss occur. More severe symptoms
include shortage of breath and coughing. These systemic and respiratory symptoms occur with initial exposure; i.e., the first day of the work week.

They progressively improve during exposure and in the absence of exposure, only to recur on re-exposure. In a work setting, symptoms appear on Monday, improve during the week and weekend and recur the following Monday. This pattern clearly distinguishes humidifier fever from hypersensitivity pneumonitis.

During the height of the reaction, medical examinations reveal the presence of late inspiratory crackles during auscultation (“listening” to the chest) and impaired gas transfer in the lungs. The chest radiograph is always normal and the lung function is normal between attacks.The cause or causes of humidifier fever are not known.

Some organisms have been isolated and incriminated during outbreaks, but as yet not indisputably identified. However, immunological investigations almost always reveal the presence of precipitating antibodies to antigens extracted from the humidifiers. In bronchial provocation tests, water from the humidifier usually reproduces the symptoms and physiological changes.

Attack rates vary considerably in reported outbreaks. Age appears to be a factor and appears to be associated with the duration of exposure and the development of antibodies. Highest incidence rate is in the winter (probably due to seasonal humidifying activity).

In addition to the tolerance pattern, or the “Monday Morning Phenomenon” of humidifier fever, it is distinguished from hypersensitive pneumonitis in other ways. Humidifier fever shows no decrease in lung function or pulmonary fibrosis, there are no radiographic changes and it seems to be brought on by comparatively low levels of antigen whereas hypersensitivity pneumonitis is associated with massive antigen

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Elizabeth J. Neal said...

Welcome to Bel-Aire a home of whole sale Humidifier systems, replacement parts and accessories.

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