HENOCH- SCHONLEIN PURPURA Flashcards
Definition
is a vasculitis of small vessels.
It is the most common cause of nonthrombocytopenic purpura in children. Charachterized by leukocytoclastic deposition of IgA in skin , joints, GI and kidneys
age
occurring between 3-10 yr
PATHOGENESIS
1-The cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6)
2- almost half of the patients had elevated antistreptolysin O (ASO)
3-by histopathology IgA-mediated vasculitis of small
vessels.
4-deposition of IgA and C3 in the small vessels of the skin and the renal glomeruli,
CLINICAL MANIFESTATIONS
The disease onset may be acute, with the appearance of several manifestations simultaneously, or insidious, with sequential occurrence of symptoms over a period of weeks or months.
Low-grade fever and fatigue occur in more than half of affected children.
The disease is characterized by a tetrad of clinical manifestations:
Palpable purpura in patients with neither thrombocytopenia nor coagulopathy
Arthritis/arthralgia
Abdominal pain
Renal disease
Edema occurs primarily in dependent areas-
renal involvementoccurs in 25-50% of children(microscopic hematuria with or without cast, proteinuria,HTN, nephritis, nephrotic….
Renal biopsy ??
hepatosplenomegaly and lymphadenopathy may be found during active disease.
A rare but potentially serious outcome of central nervous system (CNS) involvement is the development of encephalopathy ??. seizures, paresis,ataxia, focal defecit or coma.
Skin rash
The hallmark of the disease .
The rash often begins with erythematous, macular, or urticarial wheals but can also can have less typical presentations including targetoid lesions. The rash may be itchy but is rarely painful.
The lesions tend to occur in crops in buttocks and lower extrimities in a symmetrical fashion.
last from 3-10 days and may appear at intervals that vary from a few days to as long as 3-4 mo.
In fewer than 10% of children, recurrence of the rash may not end until as late as a year, and rarely several years, after the initial episode.
Damage to cutaneous vessels also results in local angioedema, which may precede the palpable purpura
Arthritis
two thirds of children with HSP
is usually localized to the knees and ankles, more in the lower limbs and oligoarticular
and appears to be a concomitant of edema.
The effusions are serous, not hemorrhagic, in nature and resolve in 2 weeks without residual deformity or articular damage.
They may recur during a subsequent active phase of the disease.
Abdominal pain
Edema and damage to the vasculature of the GI tract may also lead to intermittent abdominal pain
Also diarrhea , melena,intussception , mesenteric ischemia …
More than half of patients have occult heme-positive stools, diarrhea (with or without blood), or hematemesis.
The recognition of peritoneal exudate, enlarged mesenteric lymph nodes, segmental edema, and hemorrhage into the bowel may prevent unnecessary laparotomy for acute abdominal pain
when to suggest Intussusception
it may be suggested by;
empty right lower abdominal quadrant on physical examination or
currant jelly stools, which may be followed by complete obstruction or infarction with bowel perforation.
DIAGNOSIS
Clinical diagnosis
The pattern of crops of palpable lesions of similar hue in dependent areas of the body is characteristic.
Diagnostic uncertainty arises when the symptom complex of edema, rash, arthritis with abdominal complaints, and renal findings occurs for a prolonged period.
Differential diagnosis
Palpable purpura can occur in meningococcemia, if there are p.re-existing coagulation abnormalities (such as factor V Leiden, protein S, or protein C deficiency).
The presentation of unremitting fever, a maculopapular rash that does not reappear in crops but is prominent on the lower extremities, and peripheral arthritis suggests Kawasaki disease..
AHE
Papular-purpuric gloves and socks syndrome
LABORATORY FINDINGS
Routine laboratory tests are neither specific nor diagnostic.
moderate thrombocytosis and leukocytosis.
The erythrocyte sedimentation rate (ESR) may be elevated.
Anemia may result from chronic or acute GI blood loss.
elevated concentrations of IgA as well as IgM are usually present in 50%
negative for
antinuclear antibodies (ANA).
antibodies to nuclear cytoplasmic antigens (ANCA).
rheumatoid factor (even in the presence of rheumatoid nodules).
Anticardiolipin or antiphospholipid antibodies may be present and contribute to the intravascular coagulopathy.
Complement usually normal but can be low in some cases
Intussusception is usually ileo-ileal in location; barium enema may be used for both identification and nonsurgical reduction.
Renal involvement is manifested by red blood cells, white blood cells, casts, or albumin in the urine.
Definitive diagnosis of vasculitis, confirmed by biopsy of an involved cutaneous site, shows leukoclastic angiitis.
Renal biopsy may show IgA mesangial deposition and occasionally IgM, C3, and fibrin
TREATMENT
Symptomatic treatment
- Adequate hydration, diet and Pain control with acetaminophen
-If edema involves the scrotum, elevation of the scrotum and local cooling, as tolerated, may decrease discomfort.
Intestinal complications (e.g., hemorrhage, obstruction, and intussusception) may be life threatening and managed with corticosteroids and, when necessary, barium enema reduction or surgical reduction or resection of the intussusception.
Therapy with oral or intravenous corticosteroids (1-2 mg/kg/24 hr) for 1-2 wk is often associated with dramatic improvement of both GI and CNS complications.
COMPLICATIONS
renal involvement with development of the nephrotic syndrome.(up to 6 month after dx but rarey if initial Uax is normal )
bowel perforation.
An infrequent complication of scrotal edema is testicular torsion, which may be suggested by pain and must be treated promptly
