Allergies are often triggered by breathing in substances from the air, such as mold, dust, or pollen. Food allergies are triggered by eating certain foods. Skin allergies are caused by substances such as detergents or perfumes coming into contact with the skin. Other allergies are caused by reactions to pet fur, bee stings, or some medicines such as penicillin. Clear, and concise information in this book looks at many of the most common causes of allergies and explains what can be done to prevent or treat them.