Like other types of asthma, it is characterized by airway inflammation, reversible airways obstruction, and bronchospasm, but it is caused by something in the workplace environment.[5] Symptoms include shortness of breath, tightness of the chest, coughing, sputum production and wheezing. Some patients may also develop upper airway symptoms such as itchy eyes, tearing, sneezing, nasal congestion and rhinorrhea.[2]