rewriting answers

Description

What abnormal finding is present? Just what does the dipstick measure here, and what other test could be done on the urine?
The protein is markedly positive. The dipstick protein test uses bromphenol blue, which is more sensitive to albumin than to globulin. Thus, a sulfosalicylic acid test, which precipitates all proteins, would be helpful if one suspected globulins (Bence-Jones protein with myeloma).
What is suggested by the child’s physical findings?
The loosest skin in a child is periorbital, so this is the first place that edema is often noticed.
What other laboratory test(s) would be useful?
A 24 hour urine protein test would help establish a diagnosis of nephrotic syndrome. Do a serum creatinine to estalish that “renal function” is normal. In reality, obtaining a reliable sample on a child is difficult, and depends in large measure on how compulsive his mother is. Since the amount of creatinine excreted in the urine is relatively constant for body size, one could do a protein/creatinine ratio on what sample was obtained, and a ratio of 0 to 0.2 is likely to be normal, 0.2 to 2.0 is pathologic proteinuria, and >2 is nephrotic.
Of course, a blood pressure measurement is part of the physical examination, and an elevated blood pressure would cast some doubt on a presumed diagnosis of nephrotic syndrome from minimal change disease, as would an increasing blood urea nitrogen or creatinine, and would suggest a more serious renal disease.
What is the diagnosis?
Nephrotic syndrome. The most likely etiology in this setting is minimal change nephrotic syndrome.