Henoch-Schonlein purpura overview

# Overview
In medicine (rheumatology and pediatrics) Henoch-Schonlein purpura (HSP, also known as allergic purpura) is a systemic vasculitis (inflammation of blood vessels) characterized by deposition of immune complexes containing the antibody IgA, especially in the skin and kidney. It occurs mainly in children. Typical symptoms include palpable purpura (small hemorrhages in the skin), joint pains and abdominal pain. Most cases are self-limiting and require no treatment apart from symptom control, but the disease may relapse (in 33% of cases) and cause irreversible kidney damage (in 1%).

# Historical Perspective
The disease was named Henoch-Schonlein purpura (HSP) after Johann Schonlein and Eduard Henoch due to their role in establishing the clinical manifestations of the disease

# Classification

# Pathophysiology
Henoch-Schonlein purpura (HSP) is an immune complex-mediated disease with circulating immune complexes and IgA rheumatoid factors usually follows upper respiratory tract infections, various viruses, and the bacteria have been implicated as triggers of the disease.

# Causes
The common causes of Henoch-Schonlein purpura (HSP) are infections, medications, hypersesitivity, vaccinations, genetics etc.

# Differentiating Henoch-Schonlein Purpura from other Diseases
Henoch-Schonlein purpura should be differentiated from other immune complex mediated small vessel vasculitis such as Anti-glomerular basement membrane disease, Cryoglobulinemic vasculitis, Hepatitis C virus-associated cryoglobulinemic vasculitis, Hypocomplementemic urticarial vasculitis (anti-C1q vasculitis).

# Epidemiology and Demographics
The incidence of HSP is approximately 6-20 cases per 100,000 individuals. The prevalence of HSP is more in children of 4-6 years age group. HSP usually affects Caucasians than any other ethnic groups. Males are more commonly affected by HSP than females. The Male to female ratio is approximately 1.5-2:1.

# Risk Factors
Henoch-Schonlein purpura (HSP) is associated with following risk factors it's most common in children of 2 to 6 years, involves young boys more than girls, Asian and white race, spring, fall and winter months, Group A streptococci, Mycoplasma, Epstein-Barr virus infections, and environmental exposure of allergens, organophosphates, cold temperature.

# Screening
There is insufficient evidence to recommend routine screening for HSP.

# Natural History, Complications and Prognosis
Henoch-Schonlein purpura is a self-limiting illness in the majority of patients but can rarely lead to complications such as proteinuria, End Stage Renal Disease, myocardial infarction, pulmonary hemorrhage, pleural effusion, intussusception, orchitis, GI bleeding, bowel infarction, seizures, neuropathies. The prognosis is usually good but rarely its worse in adults with renal involvement.

# Diagnosis
Henoch-Schonlein purpura is diagnosed using a biopsy of the skin and kidney.

## History and Symptoms
The signs and symptoms of Henoch-Schonlein purpura (HSP) are skin lesions such as palpable purpura, abdominal pain, melena, bloody diarrhea, hematemesis, duodenal ulcers, arthralgia.

## Physical Examination
Physical examination of patients with HSP is usually remarkable for palpable purpura.

## Laboratory Findings
There is no specific diagnostic test available for HSP. Platelet count, coagulation studies such as PT, aPTT, and BT are done to rule out other diseases like coagulopathies. They are usually normal. Urinalysis is done to check for any blood in the urine or proteinuria for renal involvement. Serum IgA levels are elevated in the majority of patients with HSP, and in patients with renal involvement higher IgA levels are detected.

## Electrocardiogram
There are no ECG findings associated with Henoch-Schonlein purpura.

## Chest X Ray
There are no x-ray findings associated with Henoch-Schonlein purpura (HSP).

## CT

## MRI

## Echocardiography or Ultrasound

## Other Imaging Findings

## Other Diagnostic Studies

# Treatment

## Surgery
Surgical intervention is not recommended for the management of Henoch-Schonlein purpura.

## Medical Therapy
Henoch-Schonlein Purpura (HSP) is usually treated with supportive management by adequate hydration, balancing fluid and electrolyte, and controlling hypertension. Symptoms such as arthritis, edema, fever are treated with acetaminophen, leg elevation, and adequate hydration. Pharmacological management includes use of analgesics, NSAIDs, corticosteriods and various other immuno-suppressants. Plasmapheresis may be effective in delaying the progression of kidney disease and is usually done in addition to steroids.

## Primary Prevention
There are no established measures for the primary prevention of Henoch-Schonlein purpura.

## Secondary Prevention
There are no established measures for the secondary prevention of Henoch-Schonlein purpura.

## Cost-Effectiveness of Therapy

## Future or Investigational Therapies