Many people use the term "laryngitis" to mean voice change, or hoarseness. Laryngitis is actually an inflammation (irritation and swelling) of the larynx, usually caused by some other disorder, such as Laryngopharyngeal reflux (LPR), infection, smoking, or inhaling noxious fumes.
Laryngitis may be acute (short-term) or chronic (long-term). Treatment depends upon the type of laryngitis and its cause. Bacterial infections are generally treated with antibiotics. However, antibiotics are not helpful for viral infections. Antibiotics taken for another, not necessarily related reason, may actually cause fungal infections.
Inhalers, taken for asthma or other lung disease, can have this same effect, or even cause irritation from the substances in the inhaler. Laryngitis is not a single disease, but rather a word that describes an irritated, swollen larynx. It is up to your doctor to determine the cause.
Any "laryngitis" that lasts beyond two weeks, or fails to improve with antibiotics, should be evaluated by a physician, preferably one who can make a complete examination of the larynx and vocal folds.
Inflammation causes both of these vocal folds to be swollen, resulting in limited mucosal wave vibration and incomplete glottal closure.