👉 A callous is a type of skin that is thick, crusty, and often covered with dead skin. It typically forms on the surface of the skin due to friction or irritation, and it can be caused by various factors such as dehydration, allergies, or certain medications. Callouses are usually small in size and can be painful or difficult to remove. Callous formation is a normal part of the body's response to infection or injury. It serves as an initial defense mechanism to protect the skin