Snapshot A 5-year-old boy presents to the emergency room for abdominal pain and rash on his legs. He also reports having intermittent joint pains. A few weeks ago, he had an upper respiratory infection. On physical exam, he has nontender palpable purpura on his buttocks and lower extremities. His abdomen is mildly tender. Urine studies show proteinuria and hematuria. (Henoch-Schonlein purpura/IgA vasculitis) Introduction Clinical definition vasculitis caused by immune complex deposition Pathogenesis circulating antigens induce antibody formation the antibodies then bind to antigens, creating immune complexes the immune complexes then deposit in small vessels, activating complement and causing a vasculitis General clinical features palpable dark-red or purple purpura may itch, burn, or be nontender may ulcerate Studies most cases are diagnosed clinically, but a biopsy may be needed direct immunofluorescence deposition of C3, IgM, IgA, and/or IgG Cryoglobulinemic Vasculitis Clinical definition small-vessel vasculitis caused by mixed cryoglobulins affecting the skin, peripheral nervous system, and kidneys associated with hepatitis C virus (HCV) infection occurs in adults Presentation peripheral neuropathy skin involvement palpable purpura ulcerations livedo reticularis joint pain renal involvement membranoproliferative glomerulonephritis no gastrointestinal symptoms (in contrast to Henoch-Schonlein purpura) Studies cryoglobulins isolated from the serum urine studies proteinuria hematuria Treatment treat underlying HCV infection corticosteroids Henoch-Schonlein purpura (IgA Vasculitis) Clinical definition IgA-mediated small vessel vasculitis that often follows an upper respiratory infection especially with group A streptococcus or parvovirus B19 occurs in children Presentation triad of nontender palpable purpura on buttocks and lower extremities may ulcerate arthralgias colicky abdominal pain constitutional symptoms hematuria Studies urine studies proteinuria hematuria direct immunofluorescence IgA deposition in small vessels on direct immunofluorescence histology IgA deposition in small vessels on staining leukocytoclasis Treatment typically resolves spontaneously over time angiotensin-converting enzyme (ACE) inhibitor indication for persistent proteinuria, which may result in end-stage renal disease or glomerulonephritis
QUESTIONS 1 of 5 1 2 3 4 5 Previous Next (M1.CV.17.4732) An 8-year-old girl is brought to the physician by her parents due to a new rash on her feet and legs. Her parents noticed the rash one day ago, and the child has also been complaining of joint pain and abdominal pain. She has no chronic medical conditions and has not been traveling or spending time outdoors recently. She had an upper respiratory infection seven days ago which resolved on its own. On exam, her vital signs are normal, and she is generally well-appearing. Her joints have full range of motion with no evidence of trauma. Her abdomen is soft and non-distended and is mildly tender to deep palpation diffusely. The patient has the notable findings in Figure A which are non-blanchable. The results of a complete blood count are within normal limits. Her urinalysis shows > 20 RBCs. What is most likely responsible for this patient’s dermatologic findings? QID: 108620 FIGURES: A Type & Select Correct Answer 1 Thrombocytopenia 20% (52/265) 2 Mast cell degranulation 2% (5/265) 3 Bacterial infection 9% (24/265) 4 IgA immune complex deposition 66% (175/265) 5 Venous stasis 0% (1/265) M 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (M1.CV.15.74) A 7-year-old boy is brought to the emergency department by his mother. He had a recent cold, and is now complaining of colicky abdominal pain. However, his mother became very concerned and brought him to the emergency department when she noted the rash shown in Figure A. On further review, the boy says that his elbows and knees have been hurting him. A complete blood count is within normal limits. What type of pathological process underlies his disorder? QID: 106683 FIGURES: A Type & Select Correct Answer 1 Vasculitis with c-ANCA 14% (28/206) 2 IgA vasculitis 74% (152/206) 3 Telescoping of bowel segment 2% (4/206) 4 Inflammatory bowel disease 1% (3/206) 5 Anti-platelet antibody 7% (14/206) M 2 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic (M1.CV.13.68) A 3-year-old female presents to the emergency department with colicky abdominal pain, polyarthralgias and the palpable rash shown in Figure A. You are concerned that complications of her disease may include: QID: 100584 FIGURES: A Type & Select Correct Answer 1 Septic shock 5% (3/56) 2 Glomerulonephritis 73% (41/56) 3 Deafness 5% (3/56) 4 Rheumatic fever 11% (6/56) 5 Aortic regurgitation 5% (3/56) M 2 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic (M1.CV.13.47) An 3-year-old male complains of abdominal pain following an upper respiratory infection. On physical examination, you note the dermatologic abnormality shown in Figure A. Which of the following is most likely involved in the pathogenesis of this patient's disease? QID: 100468 FIGURES: A Type & Select Correct Answer 1 IgA 71% (140/198) 2 IgE 10% (20/198) 3 IgG 8% (16/198) 4 C5a 5% (10/198) 5 C3b 6% (11/198) M 1 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (M1.CV.12.2) An 8-year-old boy presents to your office with joint pain, hematuria, and blood in the stool following an episode of pharyngitis 2 weeks ago. Examination reveals palpable red lesions on the lower extremities as seen in Figure A. This patient's disease is most similar to which of the following diseases? QID: 100956 FIGURES: A Type & Select Correct Answer 1 Idiopathic thrombocytopenic purpura 17% (14/81) 2 Systemic lupus erythematosus 5% (4/81) 3 Buerger's disease (thromboangiitis obliterans) 5% (4/81) 4 Berger's disease (IgA nephropathy) 70% (57/81) 5 Osler-Weber-Rendu syndrome 1% (1/81) M 1 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic
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