Skin disease research can cover a broad range of conditions from acne to wrinkles. The skin is the largest organ in the body and many conditions can irritate, clog, or inflame your skin and can cause symptoms such as redness, swelling, burning, and itching. Allergies, irritants, your genetic makeup, and certain diseases can cause dermatitis, hives, and other skin conditions. Many skin problems, such as acne, also affect your appearance. Your skin can also develop several kinds of cancers.