Clinical Pediatrics

Idiopathic hypercalciuria is a cause of a variety of urinary tract complaints in clinical pediatrics. These include gross or microscopic hematuria, enuresis, urinary frequency or urgency, dysuria, sterile pyuria, and proteinuria in addition to renal calculi. A random urine calcium-creatinine concentration ratio can be used to initially screen for hypercalciuria. Patients with indeterminate results should have the test repeated, while those with abnormal values should receive a complete metabolic workup to determine the cause of hypercalciuria. Identifiable causes of hypercalciuria should be treated specifically, and thiazide diuretics are the preferred treatment for uncomplicated renal calculi. Pharmacotherapy in children with idiopathic hypercalciuria and symptomatology other than renal stones is controversial and should be limited to patients with severe clinical manifestations.

Evaluation of patients with symptoms suggestive of cardiac arrhythmias is difficult using standard studies if the episodes are infrequent and have a short duration. Transtelephonic electrocardio graphic recorders were provided for 41 patients with suspected arrhythmic episodes. None had previously documented arrhythmia. There were 18 males and 23 females (age range 14 months to 19 years; mean 10.9 years). The interval prior to a diagnostic transmission was 0.5 to 8 months (mean 2.5 months). Twenty-one of 41 patients (51%) provided transmissions during a typical episode, nine of which were abnormal. Paroxysmal supraventricular tachycardia was found in eight patients and unsuspected intermittent complete heart block in one patient. The remaining 12 patients had normal sinus rhythm. Twenty patients did not transmit because episodes either were too brief or did not recur. Transtelephonic monitoring was effective in the diagnosis of certain arrhythmias that are infrequent and short in duration. Normal transmitted electrocar diograms during a typical symptomatic episode excluded cardiac arrhythmias.

Infants with extracardiac anomalies or malformation syndromes frequently have associated cardiovascular malformations. Knowledge of these predictable patterns of associations allow rapid diagnosis and treatment of these infants.

Bilirubin interferes with the measurement of plasma creatinine by the kinetic colorimetric Jaffe reaction, the method currently used by many hospital laboratories. The purpose of the present study was to evaluate the influence of unconjugated bilirubin on the measurement of plasma creatinine by the AutoAnalyzer Jaffe end point method. This colorimetric method is slower but more precise and accurate in the range of 0.25 to 0.5 mg/dl. We found that bilirubin from jaundiced neonates and from stock solutions did not affect the determination of creatinine chro mogen in plasma or in saline, even at concentrations as high as 25 mg/dl. We conclude that the use of the Jaffe end point AutoAnalyzer method with a blank run before each sample will provide an accurate measurement of creatinine in the plasma of the neonate with unconjugated hyper bilirubinemia.

Isoimmune neonatal thrombocytopenia purpura (INTP) is a disease caused by platelet destruction by maternally derived antibody. Six patients were investigated. Maternal derived platelet trans fusions in two patients resulted in posttransfusion platelet counts of greater than 85,000/μl, a normal platelet survival of 7 to 10 days, and an early discharge from the hospital. In four patients, random donor platelet transfusions administered in the first week caused a transient rise of between 7 and 30,000 platelets per μl with a return to pretransfusion levels 24 to 48 hours later, confirming the ineffectiveness of this form of treatment. Corticosteroid therapy is not effective and because of its potential toxicity should not be recommended for use in INTP. Platelet antigen was identified in the parents, and maternal sensitization was proven by the presence of platelet specific antibody. Severity of the disorder was estimated by the initial platelet count and the duration in weeks for the platelet count to rise above 100,000/μl. Lymphocytotoxicity and immune lysis, as measured by the ⁵¹Chromium release assay, did not show an obvious relationship with the severity of the disorder. In our patients, high scores in the platelet suspension immunofluo rescence test related to a more severe disorder, but a larger series would be necessary to confirm this finding.

One hundred parents of infants aged 2 weeks to 6 months were surveyed at the time of routine well-child visits to assess parental knowledge about baby powder and to determine whether hospital policy of providing a free powder sample to newly delivered mothers was unwittingly promoting powder usage. Most parents (69%) reported regular baby powder use as part of routine infant skin care. Powder-users were significantly more likely than nonusers to attribute to baby powder the ability to kill bacteria and yeast and to prevent diaper rash (p < 0.01). Even among nonusers, fewer than half were aware that aspiration/ingestion of baby powder was a potential health hazard.

Almost all parents reported receiving a free sample of baby powder while in the hospital as part of a complimentary gift pack provided by the manufacturers. Most powder-users were currently using a brand they had received as a sample, and eight parents cited the receipt of a sample as the major determinant for selecting a particular brand of powder. The short- and long-term effects of distributing sample packs to newly delivered parents deserve further study.

Bilateral congenital hyperextension of the knees occurring in dizygotic twins is reported. Twin A had the mild form of the disease, genu recurvatum, while twin B had a more severe form of the disease, congenital subluxation. Hyperextension of the knee may occur as a sporadic abnormality, in conjunction with multiple dislocations or as a feature of a syndrome. Early detection and diagnosis are im portant, especially in the more severe forms of the condition, subluxation and dislocation, which require aggressive immediate intervention to prevent long-term sequelae. Conservative treatment consisting of manipulation and immobilization usually will correct the mild forms of the condition if instituted soon after birth. Prognosis is less favorable with delayed treatment, in the presence of other congenital anomalies, and with genetic syndromes.

Isolated menarche is an unusual presentation of the advanced sexual development relative to bone age found in some patients with juvenile hypothyroidism. A case is presented, demonstrating that hypothyroidism should be considered in the eval uation of vaginal bleeding in childhood, particularly if skeletal maturation is delayed.

A 14-day old infant with stomatitis due to Candida albicans presented with frequent emesis and was found to have esophagitis by barium esophagram. She responded promptly to oral Mycostatin suspension: her emesis subsided and the stomatitis resolved. Repeat esophagram on the seventh day of therapy showed complete res olution of the esophageal mucosal abnormalities. Although Candida stomatitis is common in infants, the incidence and appropriate therapy of Candida esophagitis as a complication in otherwise normal infants are unknown. This patient responded well to frequent therapy with an oral, nonabsorbable antifungal agent.

A 28-month-old white male, 7 months status postenucleation for retinoblastoma, presented with lethargy, irritability, anemia, and thrombocytopenia. Bone marrow examination revealed almost total replacement of marrow elements with clumps of small round basophilic cells. Electron microscopic study of the marrow revealed clumps of cohesive tumor cells with intermediate junctions, establishing a diagnosis of metastatic retinoblastoma.