There are more than 3,000 kinds of skin disorders. Some are temporary and easily treated, while others can persist lifelong and cause chronic symptoms, disability, and emotional distress. Some skin conditions -- such as melanoma can even be deadly. The skin is the body's largest organ which covers and protects the body. Anything that irritates, clogs, or inflames the skin can cause symptoms such as redness, swelling, burning, and itching. Allergies, irritants, your genetic makeup, and certain diseases and immune system problems can cause rashes, hives, and other skin conditions.