Lupus, Henoch-Schönlein Purpura HSP
Lupus is a disease that involves the immune system and affects about 1.5 million Americans; nearly 90% of those diagnosed with the disease are female. Normally, a person's immune system works by producing immunity cells and antibodies, special substances that fight germs and infections. But when a person has lupus, the immune system goes into overdrive and can't tell the difference between some of the body's normal, healthy cells and germs that can cause infection. So the immune system responds by making autoantibodies that attack the body's normal cells.
The three types of lupus are:
Systemic Lupus Erythematosus (pronounced: er-uh-thee-muh-toe-sus) Also called SLE, this is the type of lupus that most people mean when they talk about the disease. It was given its name by a 19th century French doctor who thought that the facial rash of some people with lupus looked like the bite or scratch of a wolf ("lupus" is Latin for wolf and "erythematosus" is Latin for red). SLE is the most serious form of lupus. Like Chantelle, about 15% of the people who have SLE first start to feel sick when they are teens. SLE can affect the skin, joints, and tendons. It may also affect organs like the brain, heart, lungs, and kidneys.
The effects of lupus on the body can be mild or severe. Most people with SLE will have kidney problems, but only about half of them will have permanent kidney damage.
Cutaneous (or skin) Lupus
This type of lupus is a skin disease that causes a rash on the face, neck, scalp, and ears. There are two types of cutaneous lupus: discoid lupus erythematosus (DLE), which can cause scarring; and subacute cutaneous lupus erythematosus (SCLE), which doesn't cause scars. Discoid lupus is a much more rare form of lupus than SLE, although about 10% of people with discoid lupus will develop a mild form of SLE. It doesn't affect other body organs the way that SLE can.
This type of lupus is caused by a reaction to certain kinds of medicines. For example, some types of anti-seizure medicines and acne medicines can cause this kind of lupus in teens. Drug-induced lupus is similar to SLE in the ways it affects the body, but once a person stops taking the medicine, the symptoms usually go away.
Henoch-Schönlein Purpura (pronounced: heh-nok shoon-line purr-puh-ruh) — usually just called HSP — is a condition that causes small blood vessels, or capillaries, to become swollen and irritated. This inflammation, called vasculitis, usually occurs in the skin, intestines, and kidneys. Inflamed blood vessels in the skin can leak red blood cells, causing a characteristic rash called purpura. Vessels in the intestines and kidneys also can swell and leak. Sometimes it's also called allergic purpura or anaphylactoid purpura.
HSP occurs much more often in kids than in adults, usually happening between ages 2 and 11. It is one of the most common forms of vasculitis in children, and boys get it about twice as often as girls.
Although no one really knows what causes HSP, doctors do know that it occurs when the body's immune system doesn't function as it should. A protein called immunoglobulin A (IgA) is deposited into the blood vessels and sets off an immune reaction. In most cases, HSP occurs after a child has had a bacterial or viral infection of the upper respiratory tract (sinuses, throat, or lungs). But certain medicines, food reactions, insect bites, and vaccinations also may cause it. HSP cannot be passed from one person to another.
HSP can affect the kidneys. Small amounts of blood or protein might be found in the urine, which occasionally can be bloody. Up to half of kids who develop HSP will have complications with their kidneys, so the doctor will probably check kidney function over several months. If the doctor suspects that HSP has caused kidney damage, your child may need to see a kidney doctor (nephrologist).