Henoch–Schönlein purpura

Editor-In-Chief: Prab R Tumpati, MD
Obesity, Sleep & Internal medicine
Founder, WikiMD Wellnesspedia &
W8MD's medical weight loss NYC, sleep center NYC
Philadelphia medical weight loss and Philadelphia sleep clinics

Henoch–Schönlein purpura
Henoch–Schönlein purpura rash on the legs
Synonyms	IgA vasculitis, anaphylactoid purpura
Pronounce	N/A
Specialty	N/A
Symptoms	Purpura, joint pain, abdominal pain, kidney involvement
Complications	Kidney failure, intussusception, bowel infarction
Onset	Typically in children aged 3–15 years
Duration	Usually self-limiting within 4–6 weeks
Types	N/A
Causes	Often follows an upper respiratory tract infection
Risks	Age, genetic predisposition, infections
Diagnosis	Clinical evaluation, skin biopsy, urinalysis
Differential diagnosis	Thrombocytopenic purpura, systemic lupus erythematosus, Kawasaki disease
Prevention	N/A
Treatment	Supportive care, corticosteroids, immunosuppressants
Medication	N/A
Prognosis	Generally good, but can lead to chronic kidney disease in some cases
Frequency	10–20 cases per 100,000 children per year
Deaths	N/A

Typical purpura on lower leg

Immunostaining showing IgA in the glomerulus of a patient with Henoch-Schönlein nephritis

Microphotograph of a histological section of human skin prepared for direct immunofluorescence using an anti-IgA antibody, the skin is a biopsy of a patient with Henoch-Schönlein purpura. IgA deposits are found in the walls of small superficial capillaries (yellow arrows). The pale wavy green area on top is the epidermis, the bottom fibrous area is the dermis.

Henoch–Schönlein purpura (abbreviated as HSP), also known under several other names including anaphylactoid purpura, purpura rheumatica, and Schönlein–Henoch purpura, is a multifaceted disease predominantly affecting the skin but also has implications for various other organs. Although children are the most commonly affected demographic, it can impact individuals of any age.

Introduction

HSP is essentially a systemic vasculitis, which means it results from the inflammation of blood vessels. Its etiological hallmark is the deposition of immune complexes containing the antibody IgA, though the precise trigger for this occurrence remains a subject of research. Its typical clinical manifestations include palpable purpura (small, raised purple spots resulting from hemorrhages), accompanied often by joint pain and abdominal discomfort. A noteworthy precursor to the onset of HSP is often an infection, with throat infections being a frequent precursor.

Clinical Presentation

The fundamental clinical manifestation of HSP is the appearance of purpura. This is invariably seen in all diagnosed cases. The triad of symptoms that define the disease includes: Purpura: Palpable and usually visible on the legs and buttocks. However, they can also manifest on the arms, face, and trunk. Arthritis: Joint pains, especially in the ankles, knees, and elbows. Hands and feet may also be affected. The arthritis is non-erosive, so it does not lead to permanent deformity. Abdominal Pain: Often colicky in nature and may be associated with nausea, vomiting, constipation, or diarrhea. In certain cases, blood or mucus may be present in the stools. A subset of patients may also experience gastrointestinal hemorrhage.

Pathophysiology

HSP is primarily a small-vessel vasculitis where immunoglobulin A (IgA) and complement component 3 (C3) complexes are deposited on various blood vessels such as arterioles, capillaries, and venules. This is somewhat similar to the pathology observed in IgA nephropathy, though the latter typically targets young adults and affects mainly the kidneys. HSP, on the other hand, is more prevalent in children and has systemic manifestations including the skin, connective tissues, scrotum, joints, gastrointestinal tract, and kidneys.

Diagnosis

The diagnosis of HSP hinges largely on its unique clinical presentation. Laboratory tests may show: Elevated levels of creatinine and urea in cases with kidney involvement. Raised IgA levels in approximately 50% of the patients. Increased C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR). A possibly raised platelet count. Histopathologically, skin or renal biopsy can show IgA deposition, aiding in a definitive diagnosis.

Classification

Multiple diagnostic criteria have been proposed for HSP, such as the 1990 American College of Rheumatology (ACR) criteria and the 1994 Chapel Hill Consensus Conference. The 2006 European League Against Rheumatism (EULAR) and Pediatric Rheumatology Society (PReS) classification emphasizes palpable purpura along with at least one additional clinical manifestation for a diagnosis.

Treatment

While HSP often resolves spontaneously, symptom control is essential. Pain management is crucial, especially for abdominal and joint pains. Although steroids are not a mainstay treatment for HSP, early administration in the disease course may mitigate symptoms and potentially reduce the risk of severe renal involvement. However, their role in preventing long-term kidney disease is still debated.

Prognosis

The prognosis for HSP patients is generally favorable. Recovery rates are notably high, especially in children. However, recurrence, especially within the first few months following the initial episode, is seen in a significant proportion of patients. This risk is especially heightened in older children and adults.

This article is a medical stub. You can help WikiMD by expanding it!
Most recent articles Ongoing trials	Wikipedia

Pediatric glossary of terms | Glossary of medical terms | Dictionary of pediatrics