Henoch-Schonlein Purpura (HSP)

Henoch-Schonlein purpura (HSP) is a form of vasculitis that affects blood vessels and is characterized by the deposition of immune complexes containing IgA antibodies. It is also known as IgA vasculitis or anaphylactoid purpura.

Causes and Risk Factors

The exact cause of HSP is unknown, but it is believed to be triggered by an abnormal immune response to certain infections, such as streptococcal pharyngitis or other bacterial or viral infections. Other potential triggers include vaccinations, medications, and food allergies.

Symptoms

The symptoms of HSP can vary in severity and may include:

• Purpura: a rash characterized by small, red-purple spots that can appear anywhere on the body, but are most commonly found on the legs, buttocks, and elbows.
• Joint pain and swelling: arthritis can occur in some cases, affecting the knees, ankles, and wrists.
• Abdominal pain: some people may experience abdominal pain, nausea, vomiting, and diarrhea due to gastrointestinal involvement.
• Kidney problems: HSP can cause kidney inflammation (nephritis), which can lead to blood in the urine, proteinuria, or kidney failure in severe cases.

Diagnosis

The diagnosis of HSP is based on a combination of clinical presentation, laboratory tests, and biopsy results. Diagnostic criteria include:

• Purpura: the presence of a characteristic rash.
• IgA deposition: the presence of IgA antibodies in affected tissues, as demonstrated by immunofluorescence or electron microscopy.
• Exclusion of other causes: ruling out other conditions that may cause similar symptoms, such as thrombocytopenia or other forms of vasculitis.

Treatment and Management

Treatment for HSP is primarily supportive and focused on managing symptoms. This may include:

• Pain management: using over-the-counter pain medications, such as acetaminophen or ibuprofen, to relieve joint and abdominal pain.
• Corticosteroids: in some cases, corticosteroids may be prescribed to reduce inflammation and prevent complications.
• Rest and hydration: getting plenty of rest and staying hydrated can help alleviate symptoms.

Complications and Prognosis

Complications of HSP can include:

• Kidney damage: in severe cases, HSP can cause permanent kidney damage or failure.
• Gastrointestinal bleeding: abdominal pain and gastrointestinal involvement can lead to bleeding or intussusception (a condition where the intestine telescopes into itself).
• Orchitis: inflammation of the testicles can occur in some cases, leading to testicular atrophy or infertility.

The prognosis for HSP is generally good, with most people recovering within a few weeks to months. However, some individuals may experience persistent or recurrent symptoms, and complications can occur in severe cases.

Frequently Asked Questions (FAQs)

What is Henoch-Schönlein purpura (HSP)?
A form of blood vessel inflammation or vasculitis that affects small vessels, typically causing skin, joint, and kidney problems.

What are the common symptoms of HSP?
Purpura (rash), joint pain, abdominal pain, and kidney involvement, which may include hematuria (blood in urine) or proteinuria (protein in urine).

Who is most commonly affected by HSP?
Children, typically between 3 and 10 years old, though it can occur at any age.

What triggers HSP?
Often follows a respiratory tract infection, but the exact cause is not fully understood and may involve immune system response.

Is HSP contagious?
No, it is not directly contagious, although the infections that may trigger it can be.

How is HSP diagnosed?
Through a combination of physical examination, medical history, blood tests, and sometimes biopsy of affected skin or kidney tissue.

What are the potential complications of HSP?
Kidney damage, gastrointestinal bleeding, and in rare cases, neurological involvement or testicular pain.

Can HSP be prevented?
No known method to prevent HSP, as its cause is not fully understood.

How is HSP treated?
Supportive care, including rest, hydration, and pain management; corticosteroids may be used in severe cases or to reduce inflammation.

What is the typical prognosis for someone with HSP?
Most people recover within several weeks to months, but kidney problems can sometimes persist or recur.