Henoch-Schonlein Purpura - An Overview

Introduction:

Henoch-Schonlein purpura is an acute immune-mediated reaction caused due to the deposition of IgA antibody complexes. It was first described in 1800 by William Heberden, an English physician. It was named after two German physicians, Dr. Johann Schonlein and Eduard Henoch, who represented the association between joint pain and purpura and the link between gastrointestinal and renal involvement. It is more common among children, and the symptoms of the disease occur due to the deposition of IgA immune complexes in the blood vessels and the body's organs.

What Is Henoch-Schonlein Purpura?

Henoch-Schonlein purpura is a form of vasculitis which is characterized by the inflammation of small blood vessels of the body. It is also known as IgA vasculitis, as it is caused due to the immune reaction mediated by the IgA antibodies. It commonly involves the small blood vessels of the joints, skin, kidneys, and gastrointestinal tract.

What Is the Etiology of Henoch-Schonlein Purpura?

The exact cause of Henoch-Schonlein purpura is unknown; the suggested causes include:

• Environmental factors.

• Genetic factors.

• Antigenic factors.

• Following infections (upper respiratory tract infections, gastrointestinal and pharyngeal infections).

• Medications such as Vancomycin, Cefuroxime, etc.

The most commonly encountered bacterial organisms associated with this condition are as follows:

• Group A Streptococcus (in 30 % of patients with Henoch-Schonlein purpura).

• Hepatitis A.

• Hepatitis B.

• Mycoplasma.

• Parvovirus.

• Campylobacter.

• Varicella.

• Coxsackie virus.

• Adenovirus.

What Is the Epidemiology of Henoch-Schonlein Purpura?

It is reported to be more prevalent among children and is also found in adults. The incidence among children is estimated to be 10 to 20 per 1,00,000 in a year. More common among children below ten years of age. Most of the cases in adults progress to renal failure. The rate of occurrence is high in white males.

What Is the Pathogenesis of Henoch-Schonlein Purpura?

The suggested pathogenesis of this condition is that the IgA antibodies are triggered due to antigenic exposure following infections, medications, and environmental factors. This would result in the deposition of IgA immune complexes in the small blood vessels of the skin, joints, gastrointestinal tract, and kidneys. As a consequence of this, there is a release of inflammatory mediators such as prostaglandins, complement C3, and lymphocytes, which bind with the immune complexes deposited along the walls of the blood vessels initiating the inflammatory reaction. The deposition of immune complexes in different organs would contribute to specific organ damage. Deposition of immune complexes along the skin causes purpura and petechiae, and renal deposition leads to glomerulonephritis (acute kidney inflammation typically caused by an immune response).

What Is the Classic Triad of Henoch-Schonlein Purpura?

The classic triad of the condition is as follows:

• Purpura - It is the red or purple discolored spots on the skin. It is seen in around 80 % of cases with the disease.

• Arthritis - Arthritis is a painful inflammation of the joints, seen in 80 % of cases with the disease.

• Abdominal pain - Pain in the abdomen due to gastrointestinal involvement is reported to be seen among 62 %.

What Are the Symptoms of Henoch-Schonlein Purpura?

The symptoms of the condition include:

• Rash.

• Fever.

• Diarrhea.

• Joint pain.

• Fatigue.

• Headache.

• Hematemesis (It is the vomiting of blood).

• Vomiting.

• Abdominal pain.

• Rectal bleeding.

• Scrotal edema (fluid buildup in the scrotum).

What Are the Major Signs of Henoch-Schonlein Purpura?

The major signs of this condition are:

• Skin Involvement - It is almost exclusively seen in patients with Henoch-Schonlein purpura. It is noticed by the presence of purpura and petechia that commonly affect the buttocks and the lower limb region.

• Gastrointestinal Involvement - The GI (gastrointestinal) signs such as nausea and vomiting post meals occur in about 30 % to 40 % of cases. Other potential complications include intussusception (it is the folding of the intestine like a telescope and one segment slips into another segment) in 3 % to 4 % of cases.

• Renal Involvement - The signs of renal involvement include proteinuria (presence of protein in the urine), hematuria (presence of blood in the urine), nephrotic syndrome (excretion of too much protein in the urine), nephritic syndrome (characterized by the presence of hypertension, hematuria, edema, and decreased urine output).

• Joint Involvement - Arthritis occurs in 15 % of patients with the disease. Inflammation of the knees, ankles, hands, and feet is seen.

• Central Nervous System - Signs such as ataxia (a condition that affects coordination, speech, and balance) and intracranial hemorrhage.

How Is Henoch-Schonlein Purpura Diagnosed?

There is no specific test to diagnose the Henoch-Schonlein purpura, and the diagnosis is usually based on the symptoms of the disease.

1. History: Medical and family history would provide a clue in diagnosing the disease. Medical history would tell the symptoms of the disease. Past medical history, such as previous infections and medications, would help in finding the cause of the underlying condition. Family history would help to understand the genetic link in families.

2. Physical Examination: A thorough physical examination would reveal the presence of rashes, purpura, petechiae, high blood pressure, inflammation of the joints, etc.

3. Urinalysis:

• Proteinuria - To check for protein in the urine.

• Hematuria - To check for blood in the urine.

• 24-hour Urine Test - Is done to quantify the amount of protein excreted in the urine.

4. Blood Test:

• C- Reactive Proteins (CRP) - This would indicate raised CRP levels.

• Erythrocyte Sedimentation Rate (ESR) - This would indicate raised ESR level.

• Serum IgA Level - This may indicate increased serum IgA in about 50 % of cases.

• Serum Creatinine and Urea Levels - Raised serum creatinine and urea levels in cases of patients with renal involvement.

How Is Henoch-Schonlein Purpura Treated?

The aim of management is to treat the symptoms and to provide supportive care for the patient. The steps in management include:

• Pain Management - Joint pain can be managed by prescribing painkillers like Acetaminophen and NSAIDs (non-steroidal anti-inflammatory drugs). But in cases with renal and gastrointestinal involvement, NSAIDs should be used with caution.

• Rehydration - Rehydration with intravenous fluids is given to patients with severe diarrhea and vomiting.

• Prednisone - Oral Prednisone is given to treat joint pain and gastrointestinal and renal manifestations. It helps in preventing the development of renal failure in children.

• Angiotensin-Converting Enzyme (ACE) Inhibitors - Are given to treat hypertension.

• Immunosuppressants - Can be given to stop the activity of immune-mediated IgA and further complications.

• Corticosteroids - Provides symptomatic relief in patients with Henoch-Schonlein purpura.

What Is the Prognosis of Henoch-Schonlein Purpura?

Henoch-Schonlein purpura shows an excellent prognosis as it is a self-limiting disease and recovery usually happens in four weeks. Studies report that Henoch-Schonlein purpura with renal involvement shows a poor prognosis, and around 1 % of patients with this condition develop renal failure.

What Are the Complications of Henoch-Schonlein Purpura?

Complications of the condition include:

• Bowel perforation.

• Gastrointestinal bleeding.

• Seizures.

• Renal failure.

• Intussusception (a condition in which a portion of the intestine folds like a telescope).

• Neuropathy (the damage or dysfunction of the nerves).

• Pleural effusion.

• Pulmonary hemorrhage.

What Are the Differential Diagnoses of Henoch-Schonlein Purpura?

• Hypersensitivity Vasculitis - It is characterized by the inflammation and damage to the blood vessels caused due to infection and drugs.

• IgA Nephropathy - This is caused due to accumulation of IgA antibodies in the kidneys.

• Thrombotic Thrombocytopenic Purpura - It is the formation of clots in small blood vessels.

• Wegener's Granulomatosis - This is a form of vasculitis characterized by the inflammation of blood vessels in the body.

Conclusion:

Henoch-Schonlein purpura is a self-limiting disease that shows a good prognosis with complete recovery in children. It is reported that around one-third of the patients with the disease show recurrence within four to six months. It shows poor prognosis in patients with renal involvement. Hence an earlier diagnosis of the condition is essential to prevent the development of renal as well as other complications associated with the disease.