What is IgA Vasculitis (Henoch-Schönlein Purpura)?
Immunoglobulin A vasculitis (IgAV), previously called Henoch-Schönlein purpura, affects small blood vessels in the joints, kidneys, gastrointestinal tract, and skin. It can also rarely impact the brain and lungs. IgAV is typically a temporary condition linked to an immune system reaction and usually resolves with supportive care. However, it can sometimes lead to serious issues like kidney failure.
This condition is named after German doctor Johann Schönlein and his student Eduard Henoch – who noticed the link between joint pain and skin rash (purpura) and kidney and digestive system involvement. However, the first person to describe this condition was an English doctor named William Heberden in the early 1800s. Nowadays, the term IgA vasculitis is preferred because it refers to the cause of the condition rather than the names of the doctors who discovered it.
It’s important to mention that IgA vasculitis with kidney inflammation shares many similarities with IgA nephropathy, the most common type of inflammation of the kidney’s filtering units (glomerulonephritis) worldwide. The key differences are that IgA vasculitis with kidney inflammation normally starts in children under 15 and is often accompanied by symptoms outside of the kidney. On the other hand, IgA nephropathy usually starts in people over 15 and often causes blood in the urine. When examined under a microscope, IgA vasculitis with kidney inflammation shows more blood vessel coloration and kidney filtering unit damage than IgA nephropathy.
Furthermore, IgA vasculitis with kidney inflammation has a 98% recovery rate. In contrast, 30% to 50% of patients with IgA nephropathy develop end-stage kidney failure within 20 years of their diagnosis. Also, IgA vasculitis with kidney inflammation usually arises more during cold weather seasons, while IgA nephropathy does not show any seasonal trends. Most of these differences are because IgA vasculitis is primarily a children’s disease, while IgA nephropathy is mainly an adult’s disease.
What Causes IgA Vasculitis (Henoch-Schönlein Purpura)?
IgA vasculitis, a disease that causes inflammation of small blood vessels, seems to be linked to environmental factors, genetics, and exposure to certain antigens, which are substances that trigger an immune response. In terms of genetics, studies have found a connection between specific genetic locations (referred to as HLA-DQA1 and DQB1 intergenic zone, HLA-DRB1*01:11/B1*13 loci, and DQA1*01:01/DQB1*05:01/DRB1*01:01 haplotype) and IgA vasculitis.
Many patients mention having an infection before their diagnosis. The most common types of infections they report are of the upper respiratory tract. However, others had gastrointestinal or throat infections beforehand.
Group A Streptococcus, a type of bacteria, have been found in a significant portion (over 30%) of patients with IgA vasculitis that also have a kidney condition called nephritis.
Other possible culprits for causing IgA vasculitis include various viruses and bacteria. Examples include the Coxsackie virus, hepatitis A and B, Mycoplasma, Parvovirus B19, the bacteria causing infectious mononucleosis, Legionella, Campylobacter, varicella (chickenpox), parainfluenza virus, influenza, respiratory syncytial virus (RSV), rotavirus, a type of herpes virus called cytomegalovirus (CMV), and adenoviruses.
There is also recent evidence suggesting a connection between IgA vasculitis and COVID-19. The COVID-19 virus might cause damage to blood vessels, leading to inflammation and the formation of immune complexes, which are groups of immune cells that form in response to antigens. It has been observed that some cases of IgA vasculitis also happen after COVID-19 vaccination.
Risk Factors and Frequency for IgA Vasculitis (Henoch-Schönlein Purpura)
IgAV is a seldom seen disorder that usually impacts children, but it can affect adults and teenagers too. The majority of the children who get it are under 10 years old. When adults have it, it tends to be more severe and has a higher chance of causing long-term kidney disease. It is the most common type of vasculitis in children, with 10 to 20 cases per 100,000 children every year. IgAV is a little more common in boys than girls. However, in adults, it affects males and females equally.
- IgAV is a rare disorder mainly seen in children, but can also affect adults and teenagers.
- Most of the children with IgAV are under the age of 10.
- This condition is more severe in adults and can often lead to long-term kidney disease.
- It is the most common kind of vasculitis in children, affecting 10 to 20 in every 100,000 kids each year.
- IgAV is slightly more prevalent in boys, but it affects both genders equally in adults.
Signs and Symptoms of IgA Vasculitis (Henoch-Schönlein Purpura)
IgA vasculitis is a condition that typically presents with symptoms including a distinct skin rash, gastrointestinal issues, joint pains, and kidney problems. The following symptoms might be observed:
- Skin rash
- Fatigue
- Headache
- Fever
- Joint pain
- Swelling under the skin
- Diarrhea
- Blood in vomit
- Abdominal pain
- Vomiting
- Bleeding from the rectum
- Swelling of the scrotum
A review in detail of the physical symptoms observed across different body systems follows:
The skin is affected in all patients with IgA vasculitis. The skin rash/lesions starts red but turns purple and fades over 10 days, mostly appearing on buttocks and lower extremities. In extreme cases, the lesions can worsen and are linked to ongoing resistance to kidney failure treatment.
Gastrointestinal issues affect 10% to 40% of patients even before the rash appears. Some patients may experience nausea and vomiting, which typically worsen after meals. Severe life-threatening complications can also occur, such as a bowel obstruction (intussusception), bowel perforation, tissue death in bowels (bowel gangrene), and severe bleeding.
Renal or kidney problems are noted in 20% to 55% of children with IgA vasculitis. Symptoms can include blood or protein in urine, nephrotic syndrome, inflammation of kidneys (nephritic syndrome), and even kidney failure. Some patients may also experience blocked urine flow from the kidney. Extreme kidney failure is a rare yet severe complication.
Joints issues commonly arise in IgA vasculitis. Approximately 15% of the patients have initial symptoms of arthritis while roughly 75% experience joint pains. These are usually temporary and are characterized by pain and swelling in the knees, ankles, hands, and feet.
Lastly, central nervous system involvement in IgA vasculitis is rare. If symptoms occur, they may present as headaches, dizziness, lack of coordination, seizures, irritability, nerve damage or bleeding in the brain.
Testing for IgA Vasculitis (Henoch-Schönlein Purpura)
IgA vasculitis is diagnosed based on the presence of small red dots on the skin (known as petechiae, which do not occur due to a low platelet count) or larger reddish-purple spots called purpura, which can be felt with touch. These skin changes mostly affect the lower legs. Apart from these, at least one of the following four symptoms should be present:
1. Stomach pain
2. Joint pain or inflammation
3. Kidney problems (marked by protein or red blood cells in the urine)
4. Certain types of kidney inflammation (proliferative glomerulonephritis) or blood vessel inflammation (leukocytoclastic vasculitis) with a predominance of antibody IgA deposits seen under a microscope.
Doctors typically order a urine test to spot red blood cells, protein, or specific structures made of red blood cells in the urine. If the test strip used for initial urine testing shows protein, your doctor will ask you to collect your urine over 24 hours for a more accurate measure of protein. This is because a presence of protein in urine is considered a sign of a possible recurrence of IgA vasculitis.
The amount of antibody IgA in your blood won’t be able to confirm or rule out the disease, as it varies considerably. However, if it is found to be significantly high, this could be a clue pointing towards IgA vasculitis. In addition, a test for antibodies against streptolysin O, a protein produced by a certain type of bacteria, may also be ordered.
Imaging tests like ultrasound may be used initially to rule out swelling in the kidneys (hydronephrosis). Endoscopy, a procedure that allows your doctor to examine your digestive tract, can reveal purpura in the first part of the small intestine (duodenum), stomach, and large intestine.
Treatment Options for IgA Vasculitis (Henoch-Schönlein Purpura)
If you have IgAV, a disease that causes inflammation in certain parts of the body, your treatment will often focus on managing symptoms and providing comfort, particularly if the disease hasn’t caused issues with your kidneys. Pain is commonly managed with medication such as acetaminophen or narcotics. We tend to avoid a group of medications called NSAIDs if you have problems with your digestive system or kidneys. If you have severe belly pain, we will likely recommend using a drug called prednisone or prednisolone, which is a type of steroid medication that helps reduce inflammation and pain.
Part of the treatment plan may involve keeping you hydrated using fluids given directly into a vein (intravenous fluids), managing pain as needed, and taking care of any skin sores or ulcers you may have.
If your kidneys are affected by IgAV, a condition called IgA vasculitis nephritis, we may need to use additional medications or therapies. These could include drugs that help to control your blood pressure and protect your kidneys (such as angiotensin-converting enzyme inhibitors), steroids to reduce inflammation, a treatment called plasmapheresis that helps to clean the blood, and medications that help to calm down your immune system (immunosuppressants).
We know that controlling a system in your body that regulates blood pressure and fluid balance (renin-angiotensin-aldosterone system) can lower protein levels in your urine, a common issue in kidney disease. This is very important in preventing future kidney problems, such as a decrease in kidney function, chronic kidney disease, or progression to a state of kidney failure requiring dialysis.
Drugs like prednisone, a type of steroid, can be beneficial in managing symptoms in your kidneys, joints, and digestive system. While this medication doesn’t stop kidney disease from happening, it does lower the chances of enduring long-term kidney problems in kids. It has also been found to help lessen the severity and duration of belly pain when given early in the treatment.
Other treatment options include using fish oil, which is known for its anti-inflammatory properties and can be more helpful than a placebo in treating IgA nephropathy, a specific type of kidney inflammation. Dapsone is another drug, which is an antibiotic known to help reduce inflammation and purpura (small purple spots caused by bleeding under the skin). Yet another treatment option is using intravenous immunoglobulin, which can be effective when the disease has rapidly damaged the kidneys. This therapy works by calming down your immune system in several ways.
What else can IgA Vasculitis (Henoch-Schönlein Purpura) be?
When diagnosing IgAV, or immunoglobulin A vasculitis, doctors need to consider other conditions that may present with similar symptoms. These include:
- IgA nephropathy (a kind of kidney disease)
- Acute kidney failure
- Acute glomerulonephritis (another type of kidney disease)
- Idiopathic thrombocytopenic purpura (a disorder causing bruising and bleeding)
- Disseminated intravascular coagulation (a condition causing small blood clots throughout the body)
- Thrombotic thrombocytopenic purpura (a condition causing blood clots in small blood vessels)
- Hemolytic uremic syndrome (a condition leading to destruction of blood cells, kidney failure and low platelet count)
- Meningococcal meningitis (infection causing inflammation of the brain)
- Hypersensitivity vasculitis (inflammation of blood vessels triggered by allergic reaction)
- Systemic lupus erythematosus (an autoimmune disease)
- Polyarteritis nodosa (an autoimmune disease causing swelling of small and medium size blood vessels)
- Bacterial endocarditis (an infection of the inner lining of the heart)
- Inflammatory bowel disease
- Wegener granulomatosis (a type of blood vessel inflammation)
- Rocky Mountain spotted fever (a bacterial infection transmitted by ticks)
It’s necessary for healthcare professionals to carefully rule out these conditions when diagnosing IgAV to ensure accurate diagnosis and treatment.
What to expect with IgA Vasculitis (Henoch-Schönlein Purpura)
IgA vasculitis is usually a condition that gets better on its own and has a great outlook for patients who do not have kidney problems. Most patients recover fully in about four weeks. However, IgA vasculitis will come back in about one-third of patients within 4 to 6 months of the first occurrence.
The long-term effects of vasculitis depend on how much the kidneys are affected. Roughly 1% of patients with IgA vasculitis will develop end-stage kidney disease, a severe condition in which the kidneys stop working. These patients may need a kidney transplant.
Possible Complications When Diagnosed with IgA Vasculitis (Henoch-Schönlein Purpura)
IgA vasculitis can affect many parts of the body and may lead to a wide array of potential problems. These complications include:
- Renal Failure – where kidneys fail to adequately filter waste products from your blood
- Proteinuria – a condition characterized by excessive proteins in the urine
- Hematuria – having blood in the urine
- Nephrotic syndrome – a kidney disorder that results in the release of too much protein in the urine
- Intussusception – a medical condition in which a part of the intestine has in-folded into another section of the intestine
- Gastrointestinal bleeding – bleeding in the digestive tract
- Bowel infarction – a condition in which part of the bowel doesn’t get enough blood
- Bowel perforation – a hole in the wall of part of the gastrointestinal tract
- CNS bleeding – bleeding in the central nervous system, which includes the brain and spinal cord
- Seizures – sudden, uncontrolled electrical disturbance in the brain
- Neuropathy – a condition in which the nerves outside of the brain and spinal cord, known as peripheral nerves, are damaged
- Pleural effusion – a condition where excess fluid accumulates between the layers of the pleura, the membrane that lines the lungs
- Pulmonary hemorrhage – bleeding from the lungs
- Testicular torsion – a serious condition caused by the testes twisting, cutting off the blood supply
Preventing IgA Vasculitis (Henoch-Schönlein Purpura)
Patients should understand that their symptoms are likely to improve within a matter of weeks. However, there is a chance that these symptoms might come back. Even though serious kidney issues are uncommon, if there are signs of this happening, patients will need intense treatment supervised by a kidney specialist (nephrologist).
