normal value, a case can be made for measurement of serum T3 concentration in such instances. C. REYNOLDS, MD, CM, MS, FRCP[C] Department of medicine St. Paul's Hospital Faculty of medicine University of British Columbia Vancouver, BC

cf T3-toxicosis in the elderly and the value of a routine assay for serum T3 in this population be assessed. We currently have such studies in progress. PAUL G. WALFISH, MD, FRCP[C], FACP Director, thyroid research laboratory and endocrine service Mount Sinai Hospital Toronto, Ont.

To the editor: Dr. Forester's reference References to the condition "apathetic T3-thyro1. INGEAR SH, BRAVERMAN LE: Active form of toxicosis" was based upon a single rethe thyroid hormone. Annu Rev Med 26: 443, 1975 port3 of a case that, on review and 2. ARNOLD BM, CASAL G, HIGGINs HP: Apathaccording to current terminology, etic thyrotoxicosis. Can Med Assoc / Ill: 957, 1974 could be classified as one of subclinic3. FAsRcLOUGH PD, BESSEl GM: Apathetic T-3 al or early hyperthyroidism secondary toxicosis. Br Med J 1: 364, 1974 to a solitary hyperfunctioning thyroid 4. PI¶-FMAN CS, CHAMBERS JB JR, READ VH: The extrathyroidal conversion rate of thyadenoma. Patients with solitary hyperroxine to triiodothyronine in normal man. I Clin Invest 50: 1187, 1971 functioning thyroid nodules, particu5. STERLING K. BELLABARBA D, NEWMAN ES, larly nodules greater than 3 cm in diaet al: Determination of triiodothyronine in human serum. I Clin Invest 48: 1150, 1969 meter, are at risk for hyperthyroidism, R: Triiodothyronine. Clan Enand I agree that the measurement of 6. HOFFENBERO docrmnol (OxI) 2: 75, 1973 7. BRITroN KE, QUINN V, ELLIs SM, Ct al: serum T3 concentration is important in Is "T4-toxicosis" a normal biochemical findsuch cases for the recognition of early ing in elderly women? Lancet 2: .141, 1975 hyperthyroidism. As I mentioned in my review of the T3-toxicosis syn- Colic and urinary tract infection drome in the Journal, an elevated serum T3 value as a possible premon- To the editor: I was very interested in itory or early manifestation of hyper- the article by Dr. Joseph N.H. Du on thyroidism may occur in any thyroid colic as the sole symptom of urinary gland lesion that has the potential to tract infection in infants (Can Med Assoc J 115: 334, 1976). induce hyperthyroidism. I am a little concerned by the It is indeed important to suspect the syndrome of apathetic (masked or author's diagnostic criteria for urinary akinetic) thyrotoxicosis in the elderly tract infection. In the three cases of since the typical clinical features of supposed urinary tract infection only hyperthyroidism are often absent.2 single cultures of urine were performed, However, in most such cases reported none of the specimens having been in the literature to date the diagnosis obtained by suprapubic puncture. Only could be confirmed by the routine T4 one culture had a significant colony and T3 resin uptake laboratory tests. count and in this case there were no The implied assumption of Drs. For- other suggestive findings; urinalysis on ester and Reynolds that a serum T3 two occasions yielded no abnormalities, value may be more helpful than a the child apparently had no fever and serum T4 value in the diagnosis of the leukocyte count was normal. All three patients in whom urinary apathetic thyrotoxicosis in the elderly may not be correct and further studies tract infection was diagnosed were subare required. In fact, as I discussed in jected to voiding cystourethrography my review, a variety of nonthyroidal (VCUG) or intravenous pyelography or illnesses, changes in nutritional status both; results were normal in one and and senescence itself may alter the bilateral reflux, which I believe may peripheral conversion of T4 to T3, giv- be found in patients without urinary ing a decrease in serum T3 concentra- tract infection, was demonstrated in tion out of proportion to that of T4, two. All three responded to ampicillin which cannot be accounted for on the with relief of symptoms. This relief, basis of reduced plasma protein bind- accompanied by the finding of radioing alone. Consequently, the measure- logic abnormalities in the urinary tract, ment of the serum T3 concentration in is cited by the author as supporting the elderly may be an unreliable test his belief that the symptoms of colic for the diagnosis of both hypothyroid. were caused by the "urinary tract inism and hyperthyroidism. This situa- fections". The relief of symptoms does tion could result in the less common not prove to me that the so-called "T4-toxicosis syndrome" seeming to urinary tract infections caused the occur more frequently in elderly pa- symptoms. The mere interest of the tients with apathetic hyperthyroidism. doctor, the support of the mother, the Perhaps this accounts for the recent assigning of a diagnosis to account for report suggesting, perhaps erroneous- the child's irritability, along with the ly, that T4-toxicosis is a normal bio- presumed reassurance that the treatchemical finding in elderly women ment would relieve the symptoms may with cardiac disease.7 Only with more well have done the trick, especially in surveys of thyroid function in elderly a condition so widely accepted to be populations can the precise incidence fraught with psychological overtones.

I am concerned that potentially hazardous radiologic renal investigations should have been ordered in these children with such slender evidence for urinary tract infection, and that other physicians with less experience than Dr. Du will turn to them in investigating colic in the newborn without first doing adequate pretesting to diagnose renal infection. However, Dr. Du has done us a service by reminding us that all infants who scream do not have colic and that we should be on the lookout for urinary tract infections in infants. To diagnose these with any degree of accuracy one really needs a bladder-tap specimen since avoiding contamination from bag specimens is so difficult. If there is growth from a bladder-tap specimen I, like Dr. Du, would treat it and then order urologic studies. Dr. Du's fourth patient did not have a urinary tract infection but presented with recurrent irritability. In this case it seems reasonable that investigation for other sources of the symptoms was undertaken in view of the patient's age and the duration of his symptoms. PJ. METCALF, MB, CH B, FRCP(CJ 601-6th Ave. S Lethbridge, Alta.

To the editor: I am grateful for Dr. Metcalf's critical comments and his interest in my paper. I share his view that unnecessary radiologic exposure is not desirable for infants; hence, one must select cases carefully. I also agree that suprapubic puncture should be done in suspected cases of urinary tract infection. However, several of his points require rebuttal. Dr. Metcalf says he believes bilateral reflux may be found in patients without urinary tract infection. As far as I can determine all significant ureterovesical reflux in infants is pathologic.1 The causes include congenital malformation, such as posturethral valve or diverticulum of the ureterovesical junction, neurogenic bladder, and inflammation. Complete radiologic recovery was evident 6 months and 1 year, respectively, after antibiotic therapy in my two patients with bilateral reflux, and, since the patients were normal in every other respect, this suggests that infection was the underlying problem. The nephrectomy specimen from my fourth patient showed evidence of both chronic and acute pyelonephritis. It was this case that made me suspect an association of colic and urinary tract infection. Asymptomatic urinary tract infection in infants and children is well my article stressed that point. The infants who had no other signs or symptoms have done well. To deny the striking response of prominent symptoms to antibiotic ther-

CMA JOURNAL/JANUARY 8, 1977/VOL. 116 19

Colic and urinary tract infection.

normal value, a case can be made for measurement of serum T3 concentration in such instances. C. REYNOLDS, MD, CM, MS, FRCP[C] Department of medicine...
266KB Sizes 0 Downloads 0 Views