HENOCH SCHNLEIN PURPURA (HSP) 1 Dr. Mohamed Haseen Basha Assistant professor ( Pediatrics) Faculty of Medicine Al Maarefa College of Science and Technology CLASSIFICATION OF CHILDHOOD VASCULITIS Predominantly large vessel vasculitis Takayasu arteritis Predominantly medium-sized vessel vasculitis Childhood Polyarteritis Nodosa Cutaneous Polyarteritis Kawasaki Disease Predominantly small vessel vasculitis Granulomatous Wegener granulomatosis ChurgStrauss syndrome Nongranulomatous Microscopic polyangiitis HSP Isolated cutaneous leucocytoclastic vasculitis Hypocomplementic urticarial vasculitis 2 3 Other vasculitides Behets disease Vasculitis secondary to infection (including Hepatitis Bassociated PAN), malignancies and drugs, including hypersensitivity vasculitis Vasculitis associated with connective tissue diseases Isolated vasculitis of the central nervous system Cogan Syndrome Unclassified HENOCH SCHNLEIN PURPURA 4 This is the most common vasculitis in children Incidence of HSP is estimated at 14-20/100,000 children per year It is more common in boys Approximately 90% of HSP cases occur in children, usually between the ages of 3 and 10 yr. HSP is more common in the winter and spring Many cases of HSP follow a documented upper respiratory infection. Many organisms have been implicated, including streptococci. HENOCH SCHNLEIN PURPURA (HSP) 5 DEFINITION Henoch-Schnlein purpura (HSP) is the most common vasculitis of childhood and is characterized by leukocytoclastic vasculitis and immunoglobulin (Ig) A deposition in the small vessels in the skin, joints, gastrointestinal tract, and kidney. 6 HENOCH SCHNLEIN PURPURA (HSP) PATHOLOGY Skin biopsies demonstrate vasculitis of the dermal capillaries and postcapillary venules. The inflammatory infiltrate includes neutrophils and monocytes. Renal histopathology typically shows endocapillary proliferative glomerulonephritis, ranging from a focal segmental process to extensive crescentic involvement. Immunofluorescence identifies IgA deposition in walls of small vessels, accompanied to a lesser extent by deposition of C3, fibrin, and IgM. 7 HENOCH SCHNLEIN PURPURA (HSP) PATHOGENESIS The exact pathogenesis of HSP remains unknown. Given the seasonality of HSP and the frequency of preceding upper respiratory infections, infectious triggers such as group A - hemolytic streptococcus, Staphylococcus aureus, mycoplasma, and adenovirus have been suspected. The common finding of deposition of IgA, specifically IgA1, suggests that HSP is a disease mediated by IgA and IgA immune complexes. HSP occasionally clusters in families, suggesting a genetic component. 8 HENOCH SCHNLEIN PURPURA (HSP) The hallmark of HSP is its rash: palpable purpura starting as pink macules or wheals and developing into Petechiae, raised purpura, or larger ecchymosis. Occasionally, bullae and ulcerations develop. The skin lesions are usually symmetric and occur in gravity- dependent areas (lower extremities) or on pressure points (buttocks) The skin lesions evolve in groups, typically lasting 3-10 days, and may recur up to 4 months after initial presentation. Subcutaneous edema localized to the dorsa of hands and feet, periorbital area, lips, scrotum, or scalp is also common. 9 HENOCH SCHNLEIN PURPURA (HSP) Musculoskeletal involvement - arthritis and arthralgias (75%). The arthritis tends to be self-limited and oligoarticular, predilection for the lower extremities, does not lead to deformities. The arthritis usually resolves within 2 wk but can recur. Gastrointestinal manifestations of HSP (80%), include abdominal pain, vomiting, diarrhea, paralytic ileus and melena; intussusception, mesenteric ischemia, intestinal perforation are uncommon. 10 HENOCH SCHNLEIN PURPURA (HSP) Renal involvement (50%), manifesting as microscopic hematuria, proteinuria, hypertension, frank nephritis, nephrotic syndrome, and acute or chronic renal failure. Progression to end-stage renal disease is uncommon in children (1-2%) Neurologic manifestations of HSP, caused by hypertension or central nervous system (CNS) vasculitis, may also occur. They include intracerebral hemorrhage, seizures, headaches, and behavior changes. Other less-common potential manifestations of HSP are orchitis, carditis, inflammatory eye disease, testicular torsion, and pulmonary hemorrhage. 11 HENOCH SCHNLEIN PURPURA (HSP) The diagnosis of HSP is a clinical one and is often straightforward when the typical rash is present. However, in at least 25% of cases, the rash appears after other manifestations, making early diagnosis challenging. The differential diagnosis for HSP depends on specific organ involvement other small vessel vasculitides, infections, acute post streptococcal glomerulonephritis, hemolytic-uremic syndrome, coagulopathies, and other acute intraabdominal processes. 12 CLASSIFICATION CRITERIA FOR HSP Palpable purpura (in absence of coagulopathy or thrombocytopenia) and 1 or more of the following criteria must be present Abdominal pain (acute, diffuse, colicky pain) Biopsy of affected tissue demonstrating predominant immunoglobulin A deposition Arthritis or arthralgia Renal involvement (proteinuria >3 grams/24 hr), hematuria or red cell casts HENOCH SCHNLEIN PURPURA (HSP) 13 HENOCH SCHNLEIN PURPURA (HSP) No laboratory finding is diagnostic of HSP. Common but nonspecific findings include leukocytosis, thrombocytosis, mild anemia, and elevations of erythrocyte sedimentation rate (ESR) and C-reactive protein involvement with blood pressure, urinalysis, and serum creatinine is necessary. Ultrasound - look for bowel wall edema or intussusception. Barium enema - diagnose and treat intussusception. biopsies of skin and kidney - particularly in atypical or severe cases, and characteristically show IgA deposition in affected tissues. ANA and ANCA are negative. 14 HENOCH SCHNLEIN PURPURA (HSP) TREATMENT Mild and self-limited HSP is supportive, adequate hydration, nutrition, and analgesia. Steroids - significant gastrointestinal involvement or other life-threatening manifestations. Prednisone (1 mg/kg/day for 1-2 wk, followed by taper) reduces abdominal and joint pain but does not alter overall prognosis nor prevent renal disease. Intravenous immune globulin and plasma exchange are sometimes used in the setting of severe disease. Chronic HSP renal disease is managed with a variety of immunosuppressants, including azathioprine, cyclophosphamide, cyclosporine, and mycophenolate mofetil. 15 COMPLICATIONS Acutely, serious gastrointestinal involvement such as intestinal perforation imparts significant morbidity and mortality. Renal disease is the major long-term complication(1-2%). Renal disease can develop up to 6 mo after diagnosis. It is recommended that children with HSP undergo serial monitoring of blood pressure and urinalyses for several months after diagnosis to monitor for the development of nephritis. An infrequent complication of scrotal edema is testicular torsion, which is quite painful and must be treated promptly. 16 HENOCH SCHNLEIN PURPURA (HSP) PROGNOSIS Overall, the prognosis for childhood HSP is excellent, and most children experience an acute, self-limited course lasting on average 4 wk. From 15-60% of children with HSP experience 1 or more recurrences, typically within 4-6 mo of diagnosis. The long-term prognosis usually depends upon the severity and duration of gastrointestinal or renal involvement. Chronic renal disease develops in 1-2% of children with HSP, and approximately 8% of those with HSP nephritis go on to have end-stage renal disease. Rarely, death may occur during the acute phase of the disease as a result of bowel infarction, CNS involvement, or renal disease. 17 18