Chemical pneumonitis after a single exposure to bleach

We present a 43-year-old woman that presents with franc dyspnea, non-productive cough and central chest pain with 2 weeks of evolution, with no fever, that she associates with a single inhalative high-concentration exposure to bleach, during normal work. She had no pre-existing atopy or pulmonary problems. Two weeks earlier, she went to the emergency department of a private hospital, having been diagnosed with right community-acquired pneumonia, having been medicated with antibiotics and bronchodilator therapy. She returned to the emergency department a week later with aggravated symptoms, due to lack of response to the prescribed antibiotic and bronchodilators.

Laboratory tests revealed mildly elevated C-reactive protein (12 mg/dL with normal range being <3.0mg/dL) and leukocytosis (17.8x10^9 with 88% of neutrophils) and the oxygen saturation levels were 92%. On auscultation of her chest, widespread expiratory wheeze was noted.

The patient was subjected to thorax radiograph (figure 1), which revealed areas of ​​discrete hypotransparency in the uppers thirds of the hemithoraces. A computed tomography (CT) scan of the chest was also performed, revealing peribrochovascular ground glass opacities and some foci of consolidation affecting the upper and middle lobes (figure 2, 3 and 4).

Given the known history of exposure and the atypical imaging pattern for community-acquired pneumonia, a diagnosis of chemical pneumonitis was made and treatment with oxygen, bronchodilators and steroids was prescribed. Her condition improved in a few days.

Chlorine-containing bleach is commonly used as a household cleaning agent. Although it is safe for household use, it can cause damage to the eyes, skin, gastrointestinal tract, and cardiovascular system[1]. Respiratory complications that develop after acute exposure to chlorine gas include rhinitis, pneumonitis, pulmonary oedema, and acute respiratory distress syndrome [1-4]. Most of the patients who developed respiratory symptoms after exposure to inhaled domestic products normally have pre-existing lung problems or atopy[4-7].  However, in our patient, there was no pre-existing atopy or pulmonary problems.

Chemical pneumonitis is an inflammation of the lungs and has been reported after exposure to a variety of industrial chemicals and respiratory irritants. The treatment is usually supportive, although steroids have been administered during the acute phase after exposure.[5] Antibiotics are usually not helpful or needed, unless there is a secondary infection.

Reactive airways dysfunction syndrome (RADS) is a disorder characterized by asthma-like symptoms resulting from a high level of exposure to an irritant gas, smoke, fume or vapour either at the workplace, at home or in the general environment, in patients not previously diagnosed with lung disease[8-10]. The incidence of developing RADS after an inhalational exposure to a chemical product has been difficult to quantify because specific information at the time of an inhalational accident (magnitude and duration of exposure) is often not available.

The treatment of RADS is similar to that of asthma. Therapy with nasal oxygen, corticosteroids and bronchodilators are recommended [11], but the response rate to bronchodilators is less than in patients with known asthma [12].

The clinical context is of utmost importance for the radiologist to raise the final diagnosis, and therefore, avoiding the use of antibiotics. Also, inhalation of an irritant substance should be considered in a patient who presents with sudden onset of symptoms affecting the eyes, skin or respiratory tract.

It is important to take precautions when using chemical products at home as household products may not be totally safe even after going through vigorous testing and approval processes.