678

Clinical notes

The Journal of Pediatrics April 1978

patient was discharged home in good condition after an uneventful course, remaining well throughout a nine-month follow-up. Evaluations of the patient's immune status and complement activity were performed immediately prior to discharge; all findings were normal. Organisms obtained from the urinary tract and shoulder sites were determined to be serotype la by Dr. Carol Baker of the Texas Medical Center, Houston. DISCUSSION Group B streptococci have long been recognized as an etiologic agent in neonatal infection,2puerperal septicemia,~and occasionally other serious systemic infections of man? The urinary tract and the female genital tract are common sites for isolation? ,~ Suppurative complications are well recognized, making infections with this organism reminiscent of those due to group D streptococci? The presence of diabetes mellitus appears to predispose the host to infectious complications, particularly in the setting of advanced disease with secondary vascular insufficiency. Infections with group B streptococci are not uncommonly located in lesions of diabetic gangrene. 2,~Although this patient had insulindependent diabetes, there was no apparent evidence of vascular compromise. Type la organisms were isolated from clean-catch urine and shoulder sites, but bacteremic or contiguous spread from an insulin injection site was not ruled out. Consequently, the source of infection in this patient remains unclear. This case would suggest that streptococci may pose a threat of infection in the diabetic patient, even in the absence of overt vascular insufficiency. More careful attention should therefore be directed to this organism as a potential pathogen in the diabetic population. Adequate antibiotic coverage for group B streptococci can be obtained with standard anti-staphylococcal therapy until culture results are known.

Kelly T. McKee, Jr., M.D. Department of Pediatrics Vanderbilt University Hospital Nashville, TN 37232

REFERENCES

1. Waldvogel FA, Medoff G, and Swartz MN: Osteomyelitis: A review of clinical features, therapeutic considerations, and unusual aspects, N Engl J Med 282:198, 260, 316, 1970. 2. Eickoff TC, Klein JO, Daly AK, Ingall D, and Finland M: Neonatal sepsis and other infections due to group B beta hemolytic streptococci, N Engl J Med 271:1221, 1964. 3. Hill AM, and Butler HM, Haemolytic streptococcal infections following childbirth and abortion. II: Clinical features with special reference to infections due to streptococci of groups other than A, Med J Aust 1:293, 1940. 4. Mannik M, Baringer JR, and Stokes JIII: Infections due to group B beta hemolytic steptococci report of three cases and review of the literature, N Engl J Med 266:910, 1962. 5. Anthony BF, and Concepcion NF: Group B streptococci in a general hospital, J Infect Dis 132:561, 1975.

Pseudohypoaldosteronism, a proximal tubular sodium wasting disease Pseudohypoa.ldosteronism is a special form of renal salt wasting, occurring in young infants with normal kidney morphology, normal glomerular filtration rate, and normal tubular functions except for sodium handling. Adrenal functions are also normal but secondary hyperreninemia and hyperaldosteronism are present. Sodium supplementation suffices to relieve the clinical symptoms and electrolyte disturbances. The primary defect in this disorder is unclear. Distal tubular unresponsiveness to aldosterone is generally believed to be the most plausible explanation. However, a series of observations in patients with pseudohypoaldosteronism argue against the "distal hypothesis" or suggest a proximal tubular defect. Spironolactone, a specific antagonist of aldosterone, provokes a tremendous increase in the loss of salt,' indicating that the hyperaldosteronism compensates at least partially for loss of sodium. Low to normal values of sweat sodium and chloride have been found repeatedly.'. ~ Normal sweat glands respond to endogenous aldosterone by retaining sodium and chloride. Sweat sodium and chloride concentrations are elevated in a number of conditions, including hypoaldosteronism and Addison disease. Therefore, normal values of sweat sodium and chloride in patients with pseudohypoaldosteronism indicate normal sensitivity of the sweat gland receptor for aldosterone. A normal aldosterone receptor mechanism has also been demonstrated in the intestine of a patient with pseudohypoaldosteronism? The sodium/potassium ratio in the urine was found to be inversely related to sodium intake. 2 This physiologic adaptive mechanism relies upon aldosterone activity. A potent synthetic mineralocorticoid hormone, 9 alpha-fluorocortisone, is effective when administered in high doses? This seems to assume normal responsiveness of the renal tubule to mineralocorticoid activity. Finally, it has been noted that some patients with pseudohypoaldosteronism have hypercalciuria.-'. ~The proximal renal tubule handles sodium and calcium equally, at least to a certain extent. A proximal disturbance in the reabsorption of sodium could result in an overwhelming sodium load for the distal tubule and result in secondary hyperaldosteronism and excessive renal excretion of sodium. We have been able to study renal tubular transport of sodium during hypotonic saline diuresis in an 18-month-old child with pseudohypoaldosteronism. Sodium supplementation had been discontinued for one year. The experiment was performed according to the plan described by Chaimovitz et al? At peak free water diuresis, when sodium reabsorption at the proximal tubule is maximally inhibited and antidiuretic hormone activity is minimal, (CH2o + Cx~) provides an indirect index of distal sodium supply and (Cn~o/CH2o + C~) x 100 estimates sodium reabsorption at the distal tubule. Free water clearance (C~2o) and sodium clearance (CNa) are determined by the following calculations: C%o = V - Cosr. and CNa = U ~ V/PN~ where V = vol-

0022-3476/78/0492-0678500.20/0

9 1978 The C. V. Mosby Co.

Volume 92 Number 4

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679

T a b l e I. D a t a f r o m p e r i o d o f m a x i m a l free w a t e r c l e a r a n c e d u r i n g h y p o t o n i c diuresis All values are in m l / m i n / d l

o f g l o m e r u l a r filtration rate

(C~o + C~)

Percentage o f sodium reabsorption in distal tubule (C.2o/ CH~o+ CN~)X 100

19.8 _+3.2 31.5 30.7 +_3.7

86.0 _+5.0 89.2 84.7 +0.6

Distal load

Control children ~' Patient Children with distal tubular acidosis and proximal bicarbonate wasting ~

Urine volume

Osmolar clearance

Free water clearance

22.1 +3.8 34.9 33.4 _+3.2

4.5 • 1.0 6.8 7.3 _+0.6

17.3 _+3.5 28.1 26.1 _+3.1

ume of urine in milliliters per minute, U ~ = concentration of sodium in the urine, and Ps~ = concentration of sodium in plasma. The results are given in Table I and are compared to the normal values obtained by Rodriguez-Soriano et aP in seven young children and to the values obtained by the same authors in three children with distal tubular acidosis and proximal bicarbonate wasting. ~ It is clear that fractional sodium reabsorption in the distal tubule, as represented by (CH~o/CH.,o + C,~ • 100) is wthin the normal range. However (C~2o + C~), which estimates sodium delivery to the distal tubule, is much higher in our patient than in normal children and is similar to the observations in three children with acidosis and proximal sodium bicarbonate wasting. e, Our data are clearly in favor of a proximal tubular defect in pseudohypoaldosteronism , but require confirmation in other patients with this disease. The results may help in determining whether pseudohypoaldosteronism is a single entity. 7 W. Proesmans, M.D. Binda ki Muaka, M.D. L. Corbeel, M.D. R. Eeckels, M.D. Department of Paediatrics University of Leuven Belgium REFERENCES 1. Royer P, Donnette J, Mathieu H, et al: Ann Pediatr 39:596, 1963. 2. Proesmans W, Geussens H, Corbeel L, and Eeckels R: Am J Dis Child 126:510, 1973. 3. Postel-Vinay M-C, Alberti G, Ricourt C, et al: J Clin Endocriuol Metab 39:1038, 1974. 4. Tieder M, Vure E, Gilboa Y, et al: Arch Fr Pediatr 33:485, 1976. 5. Chaimovitz C, Levi J, Better C, et al: Pediatr Res 7:89, 1973. 6. Rodriguez-Soriano J, Vallo A, and Crarcia-Fuentes M: J PEDIATR 86:524, 1975. 7. R/3sler A, Theodor R, Crazit E, et al: Lancet 1:959, 1973.

Sodium clearance

2.5 • 3.4 4.6 _+0.6

of sodium

Tetracycline-associated intracranial hypertension in an adolescent: A complication of systemic acne therapy Tetracycline is the currently recommended therapy for acne vulgaris in adolescents because of its suppression of inflammatory lesions and the rarity of severe side-effects.' In this age group, adverse effects from tetracycline have been limited to monilial vaginitis. The present case is reported to alert the pediatrician to the more serious complication of intracranial hypertension. CASE REPORT Patient C. J., a 14-year-old girl, three years post-menarche, was treated with tetracycline, 1 gm/day, for moderately severe acne since June, 1976. Six months later she noted the sudden onset of daily severe frontal nonthrobbing headaches accompanied by nausea, vomiting, and diplopia. At another hospital examination revealed bilateral blurring of the optic disc margins, fundal vein engorgement without venous pulsations, and weakness of the right lateral rectus muscle. Laboratory values were all within normal limits. A lumbar puncture was performed; the opening pressure was 400 mm H~O. Spinal fluid was acellular and xanthochromic; glucose concentration was 59 mg/dl and protein 31 mg/dl with normal electrophoresis, Cultures were negative for all organisms. A computer axial tomograph study of the head revealed no abnormalities. An electroencephalogram showed "slightly excessive" (3 to 6/ second) posterior activity without dominant lateralization. There was no arteriovenous malformation, aneurysm, or arterial vasospasm on cerebral angiography.. A presumptive diagnosis of benig n intracranial hypertension (pseudotumor cerebri) was made and the patient was discharged with no c h a n g e in medications except for the addition of Empirin with codeine, which was taken only intermittently arid afforded minimal relief. The symptoms disappeared following the lumbar puncture, only to return two days later. In February, 1977, the patient was seen at the Stanford Youth Clinic. Her only medications within the previous year had been

0022-3476/78/0492-0679500.20/0 9 1978 The C. V. Mosby Co.

Pseudohypoaldosteronism, a proximal tubular sodium wasting disease.

678 Clinical notes The Journal of Pediatrics April 1978 patient was discharged home in good condition after an uneventful course, remaining well th...
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