What is acne? Acne is a common skin condition that happens when hair follicles under the skin become clogged. Oil and dead skin cells plug the pores, and outbreaks of lesions (often called pimples or zits) can happen. Most often, the outbreaks occur on the face but can also appear on the back, chest, and shoulders. For most people, acne tends to go away by the time they reach their thirties, but some people in their forties and fifties continue to have this skin problem.
What is ankylosing spondylitis? Ankylosing spondylitis is a type of arthritis that causes inflammation in certain parts of the spine. Over time, this inflammation in the joints and tissues of the spine can cause stiffness. In severe cases, this may cause the bones in the spine to grow together, which can lead to a rigid spine that is difficult to bend. Many people with ankylosing spondylitis have mild episodes of back pain and stiffness that come and go. But others have severe, ongoing back pain and stiffness. Other symptoms also may develop if other areas of the body are affected
What are growth plate injuries? The growth plate is the area of tissue near the ends of long bones in children and teens that determines what length and shape the bone will be once it is done growing. Each long bone— the thigh bone, the bones in the forearm, and the bones in the hands and fingers—has at least two growth plates, one at each end. Once your child has finished growing, the growth plates close and are replaced by solid bone. The growth plates are weak areas of your child’s growing skeleton, making it easier to injure them. Injuries
What is osteonecrosis? Your bones are made up of living cells that need a blood supply to stay healthy. In osteonecrosis, blood flow to part of a bone is reduced. This causes death of bone tissue, and the bone can eventually break down and the joint will collapse. Osteonecrosis can happen to any bone, but most often it develops in the ends of long bones, such as the: Thigh bone. Upper arm bone. Less often, the bones of the elbows, ankles, feet, wrists, and hands are affected. When the disease involves part of a bone in a joint, it can
What is Paget’s disease? Paget’s disease of bone is a chronic (long-lasting) disorder that causes bones to grow larger and become weaker than normal. Usually only one or a few bones have the disease. Many people with Paget’s disease do not have symptoms. However, the bone changes can cause: Bone pain. Misshapen bones. Broken bones (fractures). Problems in the joints near the bones with the disease. With treatment, many people can: Manage their symptoms. Improve pain. Control the effects of the disease.
What is osteoporosis? Osteoporosis is a disease that causes bones to become weak and brittle. This increases your risk of broken bones (fractures). Osteoporosis is a “silent” disease because you may not have symptoms. You may not even know you have the disease until you break a bone. Breaks can occur in any bone but happen most often in: Hip bones. Vertebrae in the spine. Wrist. You can take steps to help prevent osteoporosis and broken bones by: Doing weight-bearing exercises, such as walking or dancing, and lifting weights. Not drinking too much alcohol. Quitting smoking, or not starting if
What is scleroderma? Scleroderma is an autoimmune connective tissue and rheumatic disease that causes inflammation in the skin and other areas of the body. This inflammation leads to patches of tight, hard skin. Scleroderma involves many systems in your body. A connective tissue disease is one that affects tissues such as skin, tendons, and cartilage. There are two major types of scleroderma: Localized scleroderma only affects the skin and the structures directly under the skin. Systemic scleroderma, also called systemic sclerosis, affects many systems in the body. This is the more serious type of scleroderma and can damage your blood
A type of skin cell called a dermal fibroblast can make an antimicrobial compound called cathelicidin in response to infection by acne-causing bacteria.
Human skin is home to diverse ecosystems including bacteria, viruses, and fungi. These microbial communities comprise hundreds of species and are collectively known as the skin microbiome.