Viral laryngitis is a medical condition that causes inflammation of the vocal cords. This may cause fever, sore throat, or difficulty swallowing. Other symptoms may include a weak or hoarse-sounding voice.Since this condition is caused by a virus and not bacteria, antibiotics are not an effective treatment method.xposure to second hand smoke can cause viral laryngitis. Throat lozenges can help keep the throat lubricated when a person has viral laryngitis. A sore throat is a common symptom of viral laryngitis.