Analgesic nephropathy diagnosis

Clinical evidence suggestive of analgesic nephropathy includes nocturia, renal insufficiency with severe acidosis, persistent urinary tract infection with colic, hematuria, and hypertension (40,41). Nocturia resulting from failure to concentrate urine is usually the earliest functional defect, but like the other symptoms it is non-specific, rendering the diagnosis of analgesic nephropathy difficult. A CT scan showing bilateral small kidneys with bumpy contours, and papillary calcification is accepted to be of sufficient specificity (38,39). 

Until recently, the diagnosis of analgesic nephropathy was difficult to obtain. The disease is associated with a large number of mainly aspecific clinical symptoms [80]. Renal papillary necrosis, considered as the hallmark of analgesic nephropathy, can only be directly demonstrated by autopsy, after nephrectomy or in the exceptional case of a patient eliminating a papilla [81]. In a large part of cases, the diagnosis was mainly based... 

Of 20 patients with analgesic nephropathy seen in the renal section of an American teaching hospital, the correct diagnosis had been missed in all cases by the referring physicians and was only made in 6 by the primary physicians caring for the patient in the hospital (8 ). 

Serious renal injury can develop as a late complication of pre-existing benign penicillamine nephropathy (220,225). Unfortunately, microscopic hematuria has limited predictive value for imminent serious renal injury, since in most patients who take penicillamine it is a transient or coincidental finding (SEDA-7, 260). The diagnosis of penicillamine-induced renal injury is often difficult because of the frequent association of rheumatoid arthritis with renal disorders (198,204,226-228), including spontaneous membranous glomerulopathy (229), or with injury caused by concomitant analgesics (230). 

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