Henoch-Schönlein Purpura (HSP) Hives (Urticaria)

At first, Tyler developed red patches and raised spots that turned purple and looked like bruises all over his legs and buttocks. Then he complained that his stomach and knees hurt. When his parents took him to the doctor to find out what was wrong, the doctor said that Tyler had the classic signs of Henoch-Schönlein purpura.

About Henoch-Schönlein Purpura

Henoch-Schönlein purpura (HEH-nok SHOON-line PURR-puh-ruh) — usually just called HSP — is a condition that causes small blood vessels 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 blood cells, causing a rash called purpura. Vessels in the intestines and kidneys also can swell and leak.

The condition was named after two German doctors, Eduard Henoch and Johann Schönlein, who first described the disease in the 1800s. Sometimes it’s also called allergic purpura, anaphylactoid purpura, or IgA vasculitis.

HSP occurs much more often in kids than in adults, usually between ages 3 and 10. It is one of the most common forms of vasculitis in children, and boys get it about twice as often as girls.

Causes

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 a type of antibody that works to fight infections. In HSP, IgA also gets placed in the blood vessels and causes swelling and bleeding.

It is unclear why this immune reaction occurs. It often happens after a bacterial or viral infection of the upper respiratory tract (sinuses, throat, or lungs). It is seen more often in fall, winter, and spring. Although less common, other possible triggers include certain medicines, food reactions, insect bites, and vaccinations.

HSP cannot be passed from one person to another.

Signs and Symptoms

Common signs and symptoms of HSP include:

• purpura, a raised, reddish purple rash
• joint pain and swelling
• stomach pain
• blood in the urine (pee) or other kidney problems
• fever
• headache

The rash occurs in all cases and is what helps doctors diagnose HSP. It may take the form of purpura, pinpoint red dots called petechiae, bruises, or sometimes blisters. The rash usually occurs on the legs and buttocks, but can also appear on other parts of the body, such as the elbows, arms, face, and trunk.

Most kids with HSP also have joint pain and swelling. These symptoms can happen before the rash appears. HSP most commonly affects the ankles and knees, but other joints like the hands, elbows, and feet may be affected.

Stomach pain usually starts a week after the rash appears. Pain may come and go and can be accompanied by nausea, vomiting, or diarrhea. Some kids will have blood in the stool (caused by leaky blood vessels), but it may not be visible.

HSP can affect the kidneys in some cases. Small amounts of blood or protein might be found in the urine, and the urine may look bloody.

Diagnosis

When the characteristic rash on the legs and buttocks is present, especially if accompanied by abdominal or joint pain, doctors can easily diagnose HSP. A diagnosis may be more difficult if joint pain or abdominal symptoms are present before the rash appears, or if symptoms take several weeks to show up.

The doctor also may request routine blood tests to look for signs of infections, anemia, or kidney disease. If abdominal pain is severe, imaging tests (like X-rays or ultrasound) may be needed. A stool sample can check for blood in the stool (poop). A urine sample can reveal blood or protein in the urine.

Up to half of kids who develop HSP will have problems 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).

Treatment

Symptoms of HSP usually last for about a month. Most of the time, it goes away on its own without treatment. To help your child feel better, the doctor may recommend certain medications, such as:

• antibiotics, if an infection is causing the HSP
• painkillers (such as acetaminophen)
• anti-inflammatory medicines (such as ibuprofen) to relieve joint pain and inflammation
• corticosteroids (such as prednisone) for severe abdominal pain or severe kidney disease

Also, the doctor may tell you to stop giving your child certain medications if there’s a chance that they caused the HSP.

While at home, try to keep your child as comfortable as possible. Be sure your child gets plenty of rest and drinks fluids. If your child stops eating or drinking, or develops severe abdominal pain or kidney problems, hospitalization might be necessary.

What to Expect

Most children with HSP fully recover within a month and have no long-term problems. Kids whose kidneys are affected will need to see a doctor for regular checkups to monitor kidney function.

About one-third of those who have HSP get it again, usually a few months after the first episode. If HSP does come back, it’s usually less severe than the initial episode.