Microscopic Polyangiitis (MPA) is an inflammation of the medium and small vessel walls that can affect different parts of the body including (but not limited to) the kidneys, lungs, sinuses, nerves and skin.
MPA is diagnosed in people of all ages, all ethnicities, and both genders. MPA usually affects adults in their 50s. Males suffer from this condition slightly more often than females. The reason why MPA affects some people is not known.
Over 90% of those with MPA have the disease in their kidney and lungs. Nerves, digestive tract and skin may also be involved. The eyes and nervous system can also be affected by the disease. A skin rash, usually purplish bumps and spots on the extremities, is sometimes seen. Additionally, the stomach and intestinal track can also be affected by the disease, resulting in pain or an alteration of the color of stool into black or bright red as a result of bleeding. The course of MPA is variable among patients.
Some patients may have long intervals between flares. For others, flares will be more difficult to control. Furthermore, some people with MPA will have the disease mildly with little change to their lifestyle (although they will always need to be monitored by their physicians). Others will suffer permanent damage such as kidney failure or lung scarring. Therefore, the natural history of the disease is diverse among patients.
The goal of therapy is to get the inflammation reduced and controlled usually using a corticosteroid.