The best single test to document cutaneous streptococcal infection is

Correct Answer: B

Rationale: The correct answer is B) elevated antistreptolysin O titer. In cases of cutaneous streptococcal infection, the body produces antibodies such as antistreptolysin O in response to the presence of streptococcal bacteria. Therefore, an elevated antistreptolysin O titer indicates an active or recent streptococcal infection in the body, making it the best single test to document cutaneous streptococcal infection. Option A) low serum C3 level is not specific to cutaneous streptococcal infection and can be seen in various other conditions. Option C) positive streptozyme screen is a test that detects antibodies against streptococcal antigens but is not specific to cutaneous infections and may not be the best single test for documenting such infections. Option D) antideoxyribonuclease B level is elevated in streptococcal infections, but it is more commonly associated with poststreptococcal sequelae like acute rheumatic fever rather than cutaneous infections. Understanding the appropriate diagnostic tests for specific infections is crucial in pediatric pharmacology to ensure accurate diagnosis and treatment. By knowing which tests are most indicative of certain infections, healthcare providers can effectively manage and treat pediatric patients with GU disorders caused by streptococcal infections.

Correct Answer: D

Rationale: Henoch-Schönlein purpura (HSP) is a vasculitis that primarily affects children. In the context of pediatric GU disorders, the correct answer is D) >50% crescents on renal biopsy. This is because the presence of more than 50% crescents on renal biopsy indicates severe renal involvement and potential progression to renal failure in children with HSP. Aggressive therapy, such as immunosuppressive agents, may be necessary to prevent long-term kidney damage in these cases. Option A) isolated microscopic hematuria and B) insignificant proteinuria are not indicators for aggressive therapy in HSP. These findings are relatively common in children with HSP and usually resolve spontaneously without long-term consequences. Option C) severe systemic manifestations, while concerning, do not specifically indicate the need for aggressive therapy in HSP related to renal involvement. Systemic manifestations can be managed symptomatically and may not necessarily correlate with the severity of renal disease in HSP. In an educational context, understanding the criteria for initiating aggressive therapy in pediatric GU disorders like HSP is crucial for healthcare providers managing these patients. Recognizing the significance of specific renal biopsy findings, such as crescents, can guide treatment decisions and improve outcomes for children with HSP. It is important to differentiate between benign manifestations of HSP and severe renal involvement to provide appropriate care and prevent long-term complications.

Correct Answer: C

Rationale: In hemolytic-uremic syndrome (HUS), the MOST correct statement is that kidney biopsy is rarely indicated to diagnose HUS (Option C). This is because HUS is primarily diagnosed based on clinical presentation, laboratory findings (such as low platelet count, hemolytic anemia, and acute kidney injury), and history of preceding infection, typically with Shiga toxin-producing bacteria. Performing a kidney biopsy is not necessary for the diagnosis and management of HUS. Option A is incorrect because not the majority, but a small percentage of patients with diarrhea-associated enteropathogenic type develop HUS. Option B is incorrect as stool culture is typically negative in patients with diarrhea-associated HUS, as the underlying cause is usually bacterial toxins rather than active infection. Option D is incorrect because in HUS, partial thromboplastin and prothrombin times are usually prolonged rather than low, due to the presence of microangiopathic hemolytic anemia and thrombocytopenia. Educationally, understanding the diagnostic criteria and clinical features of HUS is crucial for healthcare professionals involved in the care of pediatric patients. It is important to recognize the key differences between HUS and other similar conditions to ensure appropriate management and timely intervention. Additionally, knowing when certain diagnostic tests like kidney biopsy are indicated helps in avoiding unnecessary procedures and optimizing patient care.

Correct Answer: B

Rationale: The correct answer is B) corticosteroid therapy. Hypercalciuria, an excessive amount of calcium in the urine, can be seen in patients undergoing corticosteroid therapy. Corticosteroids can increase the intestinal absorption of calcium and decrease renal calcium excretion, leading to hypercalciuria. Option A) hypoparathyroidism is incorrect because this condition is characterized by low levels of parathyroid hormone, which would actually lead to hypocalciuria rather than hypercalciuria. Option C) vitamin D deficiency is incorrect as it would lead to decreased intestinal absorption of calcium, potentially causing hypocalcemia, rather than hypercalciuria. Option D) oral thiazide diuretics therapy is incorrect because thiazide diuretics can actually be used to treat hypercalciuria by decreasing renal calcium excretion. In an educational context, understanding the causes of hypercalciuria is crucial for healthcare professionals managing pediatric GU disorders. Recognizing the impact of different medications and conditions on calcium metabolism helps in making accurate diagnoses and treatment decisions for pediatric patients. It also highlights the importance of medication management and monitoring in pediatric populations to prevent potential complications related to calcium imbalances.

Correct Answer: B

Rationale: In exercise-induced hematuria, the correct answer is B) no dysuria. This is because exercise-induced hematuria typically presents with blood in the urine without associated pain or discomfort during urination. This is a key distinguishing feature of this condition. Option A) stating that blood clots are rarely seen in urine is incorrect as clots can be present in exercise-induced hematuria, especially following intense physical activity. Option C) mentioning abnormal findings on cystoscopy is also incorrect as in exercise-induced hematuria, cystoscopy typically reveals normal bladder and urethral anatomy. Option D) resolution after 7 days is incorrect because exercise-induced hematuria usually resolves spontaneously within 48 to 72 hours after the cessation of strenuous exercise. In an educational context, understanding the characteristics and presentation of exercise-induced hematuria is crucial for healthcare providers, especially those working with pediatric populations. By knowing the typical features of this condition, healthcare professionals can make accurate diagnoses, provide appropriate reassurance to patients and parents, and recommend proper management strategies. This knowledge also helps in differentiating exercise-induced hematuria from other more serious urological conditions, ensuring timely and effective care for pediatric patients.