Here's some interesting information from the NYU Voice Center about allergies and voice:
Clinically, in our experience, although there are no obvious changes in the larynx due to allergy, there are some changes in the throat and nose, which affect the voice. Allergy causes swelling of nasal tissues, which can alter the voice. Additionally, allergy can increase nasal drainage and lead to frequent throat clearing, which may irritate the vocal cords. It is therefore important to include allergy as a consideration in evaluating patients with hoarseness.
That being said, the majority of patients that have been told they have hoarseness due to allergy (symptoms such as mucus in their throat, frequent throat clearing, a lump in the throat), actually have silent, undiagnosed acid reflux disease. A proper evaluation of the hoarseness is necessary to distinguish the different potential causes of their hoarseness.
