Anaphylactoid purpura

By Medically reviewed by hellodoktor


What is anaphylactoid purpura?

Anaphylactoid purpura is a rare disorder that causes inflammation and bleeding in the small blood vessels in your skin, joints, intestines and kidneys. There are many different conditions that feature the inflammation of vascular (vasculitis). Each of the forms of vasculitis involve certain characteristic blood vessels.

The most typical feature of anaphylactoid purpurais a purplish rash, especially on the lower legs and buttocks. This condition can also cause abdominal pain and aching joints. Rarely serious kidney damage can occur.

Anaphylactoid purpura usually ends after four to six weeks, sometimes with recurrence of symptoms over this period, but with no long-term consequences. If organs such as the kidneys and intestines are influenced, treatment is often needed and it is important to have regular follow-up to prevent serious complications.

How common is anaphylactoid purpura?

This health condition is extremely common. It occurs more often in boys than in girls. In children, the male-to-female ratio is 1.5-2:1. In adults, the male-to-female ratio is approximately 1:1. Anaphylactoid purpura can affect anyone. But it’s most common in children between the ages of 2 and 6. Please discuss with your doctor for further information.


What are the symptoms of anaphylactoid purpura?

The common symptoms of anaphylactoid purpura are:

  • Rash (purpura). Reddish-purple spots, which look like bruises, are the most distinctive sign of anaphylactoid purpura. The rash develops mainly on the buttocks, legs and feet, but it can also appear on the arms, face and trunk and may get worse in areas of pressure, such as the sock line and waistline.
  • Swollen, sore joints (arthritis). People with anaphylactoid purpuraoften have pain and swelling around the joints, mainly in the knees and ankles.
  • Gastrointestinal symptoms. Many children with anaphylactoid purpuradevelop gastrointestinal symptoms, such as abdominal pain, nausea, vomiting or bloody stools.
  • Kidney involvement. anaphylactoid purpuracan also affect the kidneys. In most cases, this shows up as protein or blood in the urine, which you may not even know is there unless you have a urine test done.

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.


What causes anaphylactoid purpura?

In anaphylactoid purpura, some of the body’s small blood vessels become inflamed, which can cause bleeding in the skin, abdomen and kidneys. However, why this initial inflammation develops isn’t clear. It may be the result of the immune system responding inappropriately to certain triggers. It has been known to occur after a bacterial or viral infection of the throat, airways or lungs (respiratory tract infection).

Anaphylactoid purpura cannot be spread from person to person and doesn’t usually run in families.

Risk factors

What increases my risk for anaphylactoid purpura?

There are many risk factors for anal fistula, such as:

  • Age. The disease affects primarily children and young adults, with the majority of cases occurring in children between 2 and 6 years of age.
  • Sex. Anaphylactoid purpurais slightly more common in boys than girls.
  • Race. White and Asian children are more likely to develop anaphylactoid purpurathan are black children.
  • Time of year. anaphylactoid purpurastrikes mainly in autumn, winter and spring but rarely in summer.

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How is anaphylactoid purpura diagnosed?

Lab tests

No single test can confirm anaphylactoid purpura, but these tests can help rule out other diseases and make a diagnosis of anaphylactoid purpura seem likely. They may include:

  • Blood tests. Your blood may be tested if your diagnosis isn’t clear based on your signs and symptoms.
  • Urine tests. Your urine may be tested for evidence of blood and to determine if your kidneys are still working properly.


Your doctor may take a small sample of skin to be examined under a microscope. In cases of severe kidney involvement, your doctor may suggest a kidney biopsy to help guide treatment decisions.

Imaging tests

Your doctor may recommend an ultrasound to rule out other causes of abdominal pain and to check for possible complications, such as a bowel obstruction.

How is anaphylactoid purpura treated?

Anaphylactoid purpura usually disappears within a month with no lasting ill effects. Bed rest, plenty of fluids and over-the-counter pain relievers may help.


The use of corticosteroids, such as prednisone, in treating or preventing complications of anaphylactoid purpura is controversial. They’re most often used to treat severe gastrointestinal symptoms.


If a section of the bowel has folded or ruptured, surgical repair will be required.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage anaphylactoid purpura?

The following lifestyles and home remedies might help you cope with anaphylactoid purpura:

Home care focuses on keeping people with mild anaphylactoid purpura comfortable while the disease runs its course. Bed rest, plenty of fluids and over-the-counter pain relievers may help.

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: July 31, 2017 | Last Modified: September 12, 2019

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