Canker sores are small ulcers inside the mouth. They are also called aphthous ulcers. Unlike cold sores, which appear as painful, small blisters and are very contagious, canker sores are not caused by a virus. Certain foods or nutritional deficiencies may trigger a canker sore, as can emotiona...
The medical term for such a severe allergic reaction is anaphylactic shock. It's more common with bee, wasp and fire ant stings, medicinal drugs like penicillin and foods ranging from peanuts to shellfish. But even common outdoor plant allergens like ragweed pollen can trigger a life ...