Questions of the Week # 12, 13

Q12) A 12 y/o boy is brought to you by his mother for skin rash and complaints of intermittent abdominal pain, joint pains for past 2 days. He did have an upper respiratory infection about 2 days ago. On physical exam, his vitals are normal. Abdomen is benign with out any tenderness or rigidity. However, you notice patchy purple discolorations on his extremities and the back. Lab studies are obtained that revealed

WBC: 6.6 , HGB: 15.3 , MCV: 88 , Platelets: 290,000 ( normal 180k to 400k)
BUN: 11 , Creatinine : 0.6 ( normal) , Anti streptolysin O titer : negative
Streptozyme : negative ,Urine dipstick : normal without any blood
Urinalysis : normal/ no rbcs/ no protein
The mother is very anxious and asks about the long term prognosis of her son. Your response :

A) Reassure the mother that boys disorder is self limiting and does not require any follow up
B) Tell her the boy needs to be admitted and treated vigorously to prevent renal failure
C) Tell her that renal failure develops 100% of such cases and hence needs very cautious follow up
D) Tell her that 50% of such cases progress to end stage renal disease.
E) Tell her that the boy requires follow up monthly urinalysis for at least 3 months in order to make sure there is no heamaturia/ renal dysfunction.

Q13) If the boy presented with Renal failure in the above case, the most likely underlying pathology would be :
A) IgA mediated vasculitis
B) Post streptococcal glomerulonephritis
C) Anti GBM disease
D) Acute tubular necrosis
E) Interstitial Nephritis.

Copy Rights : Archer USMLE Reviews

4 Responses

  1. 12. Its is more likely to be Henoch–Schonlein purpura because of the classic symptoms of abd pain, purpura and joint pain in an adolescent patient.
    This disease is usually self-limiting, so the answer would be A. reasuurance.

    13. Its an IgA mediated vasculitis(A)

  2. I agreed it’s HSP. The boy needs to be admitted and treated in the hospital to prevent renal complication. 12-b and 13-a.

  3. Answers: E and A

    E) Tell her that the boy requires follow up monthly urinalysis for at least 3 months in order to make sure there is no heamaturia/ renal dysfunction

    The patient has non thrombocytopenic purpura associated with abdominal pain and arthralgias.These features are consistent with the diagnosis of Henoch Schonlein Purpura. The differential diagnosis of HSP is vast ( ITP, menigococcal spesis, acute abdomen) however, a non-thrombocytopenic purpura is a big clue. Diagnosis is clinical and not difficult when all the classic symptoms are present : Rash, abdominal pain, arthralgias and often, renal involvement. the classic 4 symptoms present (rash, abdominal pain, arthralgia, and evidence of renal involvement). When the presentation is less clear, a biopsy of involved organ ( skin or kidney) to demonstrate leucytoclastic vasculitis with IgA deposition.

    The initial episode of HSP usually resolves within one month. Renal disease is seen in 20 to 50% cases. Though it can be seen at presentation of HSP, the onset of renal disease in HSP may also be delayed and can occur within weeks to months after other symptoms of HSP. Renal involvement is usually mild and presents with asymptomatic hematuria and proteinuria. However, in less than 10% cases it can lead to nephrotic syndrome and severe renal disease. About 2 to 5% may progress to end stage renal disease.

    In children with no renal impairment at presentation, Urinalysis and blood pressure monitoring should be followed monthly for three months after presentation. Children presenting with renal involvement at the first presentation should be followed more carefully i.e; urinalysis every week for first 2 months and then every month for one year. Patients with persistent proteinuria, hypertension, or renal insufficiency should be referred to nephrology for further evaluation and treatment.

    Option A is incorrect because though the disease is self limiting, it needs to be followed for possible development of renal impairment.

    Option B is incorrect – no admission required because the boy has an initial mild attack of HSP with out any renal impairment at this time.

    Option C is incorrect because renal impairment may be seen only in about 20 to 50% cases of HSP. Renal involvement is typically seen with in one month of onset of systemic symptoms.

    Option D is incorrect because only 2 to 5% patients progress to End Stage Renal Disease

    Q13) A . HSP is IGA mediated vasculitis. IgA nephropathy and Henoch-Schoenlein purpura are two different entities that can lead to renal disease. The mechanism of renal disease in HSP is a vasculitis that is mediated by IgA. Extrarenal manifestations are seen most often in patients with Henoch-Schoenlein purpura where as they are uncommon in IgA nephropathy. HSP associated renal disease tends to be self-limiting in majority of cases where as IgA nephropathy is often associated with persistent or recurrent hematuria and/ or proteinuria.

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