Liquid Bleach Vapors

My Ten-year-old son was exposed to liquid bleach vapors as I was trying to clean permanent marker off of his notebook.  Overnight he start having shortness of breath.  I took him to Urgent Care, they gave him a albuterol treatment and liquid prednizone and wrote out a prescription for it for three days.
He's breathing a little better but has a lot of mucus.  I would like to know does this exposure lead to permanent lung damage?  He is also Sickle Cell Trait.

[National Jewish Health]

Whether permanent damage occurs, when the lungs are exposed to a chemical irritant, depends on the intensity of the exposure, how strong and how long.  What you describe is probably the equivalent of acute bronchitis and will probably not result in permanent damage, but cough and mucus could persist for some weeks.  The treatment prescribed, including the prednisone, was quite appropriate.

In some instances, such as this, the chemical can precipitate asthma.  Fortunately, his having Sickle Cell Trait should not be a factor in the resolution of this illness.

Good luck