Croup

Can refer either to a general inflammation of the larynx, resulting in a painful spasm or cough, or to a specific condition in which a false membrane develops over the throat accompanying the coughing and spasms.
Croup is best treated by the ingestion of hard, rough-textured food such as rock candy (swallowed in chunks) and bread crusts, and highly acidic foods such as freshly squeezed lemon juice or vinegar. The rough-textured foods crape the infected tissue off the throat an into the stomach, where the digestive juices will dissolve it; the acidic foods also "burn off" the infection and thus soothe the inflamed tissue.