A systemic disease is a disease that affects other parts of the body, or even the whole body. The hands are complex. They are composed of many types of tissue including blood vessels, nerves, skin and skin-related tissues, bones, and muscles/tendons/ligaments. Because of this complexity, the hands may suffer from side effects of systemic diseases. Here are some examples that may affect the hand:
1. Arthritic Swelling: Swelling of the middle joint of a finger is called a Bouchard’s node, and swelling at the small finger joints are called Heberden’s nodes.
2. Dactylitis: Dactylitis can sometimes be associated with psoriatic arthritis. It can cause swelling and stiffness in the fingers. There also may be pain. This swelling may be improved with medicines for the problem causing it.
3. Mucous Cyst: With a mucous cyst, if the skin becomes thin, the cyst may break resulting in drainage of a clear sticky fluid. This may allow bacteria to reach the nearby joint, causing a joint or bone infection.
4. Red Dots: Sometimes, small red dots will appear right around the nail cuticles. This has been seen in dermatomyositis, systemic lupus, and scleroderma.
5. Leukonychia: Leukonychia can be seen with viral infections, intestinal and kidney diseases, poisoning, and medicines. With this disease, the nail may come loose because of fungal infections or other causes.
6. Red Streaks: Red streaks seen in the fingernail area can be due to hemorrhage (bleeding). These are called splinter hemorrhages and have been seen in endocarditis (heart infection), although also reported in psoriasis and trichinosis.
7. Psoriasis: Psoriasis commonly affects the nail and nailbed. Pits in the nail, loosening, blood streaks beneath the nail, and other changes may occur.
8. “Pincer” Nail: A “Pincer” nail is abnormally curved and can be seen at birth or simply due to aging. However, it can also be caused by changes in the bone due to a disease.