Characterization of the duration of treatment with diazoxide in infants with prolonged hyperinsulinism (PHI).

Background Prolonged neonatal hyperinsulinism (PHI) causes hypoglycemia in the neonatal period and is associated with perinatal stress. Even though diazoxide is an effective treatment option for PHI, it has serious adverse effects making an argument for safe yet expeditious wean off of diazoxide while ensuring normoglycemia. The objective of this study was to characterize clinical course, dose requirement and duration of treatment with diazoxide in our cohort of infants diagnosed with PHI. Methods A retrospective chart review of infants diagnosed with PHI during a 6-year period was done documenting the diagnostic workup and the duration of treatment with diazoxide. Results PHI was diagnosed (n = 20; mean ± standard deviation [SD]) at 14.3 ± 22.4 days. Elevated insulin (8.3 ± 8.4 mIU/L), normal cortisol (15.5 ± 6.6 µg/dL [6-21]), normal growth hormone (18.8 ± 15.7 ng/mL [0.1-6.2]) and inappropriate low serum free fatty acids (0.3 ± 0.2 mmol/L [>1.5]) levels were measured during hypoglycemia (plasma glucose <50 mg/dL). Detectable insulin at the time of hypoglycemia was measured in 17 of 20 infants while the same number (17/20) of infants had a positive glucagon stimulation test (GST). The dose of diazoxide was 10 ± 3.7 mg/kg/day and duration of treatment was 44.9 ± 27.9 days. Conclusions This study illustrates that the duration of treatment with diazoxide in infants with PHI can be shorter than previously reported in the literature. We speculate that active tapering of diazoxide started within a week after discharge from hospital as well an outpatient tapering of diazoxide based on glucose monitoring were possible reasons for this outcome.

A Rare and Potentially Fatal Etiology of Hypercalcemia in an Infant.

Hypercalcemia is an uncommon finding in children. Hypercalcemia has various etiologies including parathyroid dependent and independent mechanisms. Increased activity of the 1-alpha-hydroxylase enzyme in granulomatous diseases is a well-defined but an extremely rare cause of hypercalcemia in pediatric patients, particularly in infants. We describe the case of an infant who presented with failure to thrive, hepatosplenomegaly, and hypercalcemia who was initially treated with steroids but was later diagnosed with disseminated histoplasmosis in the absence of an underlying immunodeficiency. Extra caution should be used before considering steroids for the treatment of hypercalcemia and, whenever possible, steroids should not be initiated until a definite etiology is identified.

Allergic and non-allergic skin reactions associated with growth hormone therapy: elucidation of causative agents.

BACKGROUND: Allergic and non-allergic skin reactions to recombinant human growth hormone (rhGH) are uncommon and infrequently reported. However, physicians should be aware of these potential side effects to determine whether the reactions constitute true allergies and how to proceed with growth hormone therapy. To review allergic and non-allergic skin reactions caused by rhGH and subsequent diagnostic workup and management options. CASE PRESENTATION: We report the case of a 12-year-old healthy male presenting with idiopathic short stature. He developed an itchy skin rash over the chest and abdomen, 15 min after administration of the first dose of rhGH, leading us to review allergic and non-allergic skin reactions to rhGH. In our patient, an immediate skin reaction after administration of rhGH prompted a concern about a type I hypersensitivity reaction (HS) and the discontinuation of rhGH. However, after a dermatologic evaluation and observed administration of rhGH without subsequent rash, the initial eruption was likely an exacerbation of his underlying atopic dermatitis and a type I HS was felt to be unlikely. The rhGH was resumed and he has been on rhGH for the past 1 year with no recurrence of rash and with improvement in growth velocity. CONCLUSIONS: Though rare, allergic and non-allergic skin reactions are known to occur with rhGH. It is important to know if the allergic reaction was due to the growth hormone molecule or one of the preservatives. It is also important to consider a non-allergic reaction due to flare up of underlying skin disorders as in our patient.

Spiral Fracture in Young Infant Causing a Diagnostic Dilemma: Nutritional Rickets versus Child Abuse.

Fractures are uncommon in young, nonambulatory infants. The differential diagnosis includes nonaccidental injury (NAI) and metabolic bone disease, including rickets. While rickets typically present after six months of age, multiple cases have been reported in younger infants. We report a case of an 11-week-old male infant who presented with a spiral fracture of the humerus and no radiologic evidence of rickets. A detailed psychosocial assessment failed to reveal any risk factors for NAI. The patient had elevated alkaline phosphatase and PTH with low 25 hydroxyvitamin D and 1,25 dihydroxyvitamin D levels. Additionally, the mother was noncompliant with prenatal vitamins, exclusively breastfeeding without vitamin D supplementation, and had markedly low vitamin D levels 15 weeks postpartum. The biochemical data and history were consistent with rickets. Given the diagnostic dilemma, the working diagnosis was rickets and the patient was started on ergocalciferol with subsequent normalization of his laboratory values and healing of the fracture. These findings are consistent with nutritional rickets largely due to maternal-fetal hypovitaminosis D. This case highlights that in young infants rickets should be considered even in the absence of positive radiologic findings. Additionally, it illustrates the importance of maintaining adequate vitamin D supplementation during pregnancy and early infancy.

Clinical Phenotype in a Toddler with a Novel Heterozygous Mutation of the Vitamin D Receptor.

We present the clinical phenotype of a toddler who presented with vitamin D-resistant rickets, with one of the highest initial levels of alkaline phosphatase and parathyroid hormone (PTH) levels reported in the literature. The toddler had novel compound heterozygous mutations in the ligand-binding site of the vitamin D receptor and had an excellent response to calcitriol (1,25(OH)2D).

Skeletal growth and bone mineral acquisition in type 1 diabetic children; abnormalities of the GH/IGF-1 axis.

Type 1 diabetes mellitus (T1DM) is one of the most common chronic diseases diagnosed in childhood. Childhood and adolescent years are also the most important period for growth in height and acquisition of skeletal bone mineral density (BMD). The growth hormone (GH)/insulin like growth factor -1 (IGF-1) axis which regulates growth, is affected by T1DM, with studies showing increased GH and decreased IGF-1 levels in children with T1DM. There is conflicting data as to whether adolescents with TIDM are able to achieve their genetically-determined adult height. Furthermore, data support that adolescents with T1DM have decreased peak BMD, although the pathophysiology of which has not been completely defined. Various mechanisms have been proposed for the decrease in BMD including low osteocalcin levels, reflecting decreased bone formation; increased sclerostin, an inhibitor of bone anabolic pathways; and increased leptin, an adipocytokine which affects bone metabolism via central and peripheral mechanisms. Other factors implicated in the increased bone resorption in T1DM include upregulation of the osteoprotegerin/ receptor-activator of the nuclear factor-κB ligand pathway, elevated parathyroid hormone levels, and activation of other cytokines involved in chronic systemic inflammation. In this review, we summarize the clinical studies that address the alterations in the GH/IGF-I axis, linear growth velocity, and BMD in children and adolescents with T1DM; and we review the possible molecular mechanisms that may contribute to an attenuation of linear growth and to the reduction in the acquisition of peak bone mass in the child and adolescent with T1DM.

Use of Chlorothiazide in the Management of Central Diabetes Insipidus in Early Infancy.

Management of central diabetes insipidus in infancy is challenging. The various forms of desmopressin, oral, subcutaneous, and intranasal, have variability in the duration of action. Infants consume most of their calories as liquids which with desmopressin puts them at risk for hyponatremia and seizures. There are few cases reporting chlorothiazide as a temporizing measure for central diabetes insipidus in infancy. A male infant presented on day of life 30 with holoprosencephaly, cleft lip and palate, and poor weight gain to endocrine clinic. Biochemical tests and urine output were consistent with central diabetes insipidus. The patient required approximately 2.5 times the normal fluid intake to keep up with the urine output. Patient was started on low renal solute load formula and oral chlorothiazide. There were normalization of serum sodium, decrease in fluid intake close to 1.3 times the normal, and improved urine output. There were no episodes of hyponatremia/hypernatremia inpatient. The patient had 2 episodes of hypernatremia in the first year of life resolving with few hours of hydration. Oral chlorothiazide is a potential bridging agent for treatment of central DI along with low renal solute load formula in early infancy. It can help achieve adequate control of DI without wide serum sodium fluctuations.

Salivary Testosterone during the Minipuberty of Infancy
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BACKGROUND: The hypothalamic-pituitary-gonadal axis is transiently activated during the postnatal months in boys, a phenomenon termed "minipuberty" of infancy, when serum testosterone (T) increases to pubertal levels. Despite high circulating T there are no signs of virilization. We hypothesize that free T as measured in saliva is low, which would explain the absence of virilization. METHODS: We measured serum total T and free T in saliva using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in 30 infant boys, aged 1-6 months, and in 12 adolescents, aged 11-17 years. RESULTS: Total serum T in all infants was, as expected, high (172 ± 78 ng/dL) while salivary T was low (7.7 ± 4 pg/mL or 0.45 ± 0.20%). In contrast, salivary T in the adolescents was much higher (41 ± 18 pg/mL or 1.3 ± 0.36%) in relation to their total serum T (323 ± 117 ng/dL). We provide for the first time reference data for salivary T in infants. CONCLUSION: Measurement of salivary T by LC-MS/MS is a promising noninvasive technique to reflect free T in infants. The low free T explains the absence of virilization. The minipuberty of infancy is more likely of intragonadal than peripheral significance.
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Transdermal testosterone gel for induction and continuation of puberty in adolescent boys with hepatic dysfunction.

Treatment to induce puberty in boys is indicated in those who do not undergo spontaneous development at a normal age. Stimulating development of the secondary sex characteristics is possible using gradually increasing doses of testosterone esters (TEs) via intramuscular (IM) administration, which is the most widely used method of testosterone (T) supplementation. When TEs are administered as monthly injection, serum T levels exhibit large fluctuations with supraphysiologic levels seen immediately after the injection followed by a decrease into the low range. Transdermal T (TT) has also been used for replacement therapy in adult males with hypogonadism and this provides steadier serum T levels. We report three adolescent boys with delayed puberty who were treated with TT gel for pubertal induction/continuation. This route was chosen as an alternative therapy due to their hepatic dysfunction, as is known that TT avoids the hepatic first-pass metabolism.

Unusual phenotype of congenital adrenal hyperplasia (CAH) with a novel mutation of the CYP21A2 gene.

Gonadotropin independent sexual precocity (SP) may be due to congenital adrenal hyperplasia (CAH), and its timing usually depends on the type of mutation in the CYP21A2 gene. Compound heterozygotes are common and express phenotypes of varying severity. The objective of this case report was to investigate the hormonal pattern and unusual genetic profile in a 7-year-old boy who presented with pubic hair, acne, an enlarged phallus, slightly increased testicular volume and advanced bone age. Clinical, hormonal and genetic studies were undertaken in the patient as well as his parents. We found elevated serum 17-hydroxyprogesterone (17-OHP) and androstenedione that were suppressed with dexamethasone, and elevated testosterone that actually rose after giving dexamethasone, indicating activity of the hypothalamic-pituitary-gonadal (HPG) axis. An initial search for common mutations was negative, but a more detailed genetic analysis of the CYP21A2 gene revealed two mutations including R341W, a non-classical mutation inherited from his mother, and g.823G>A, a novel not previously reported consensus donor splice site mutation inherited from his father, which is predicted to be salt wasting. However, the child had a normal plasma renin activity. He was effectively treated with low-dose dexamethasone and a GnRH agonist. His father was an unaffected carrier, but his mother had evidence of mild non-classical CAH. In a male child presenting with gonadotropin independent SP it is important to investigate adrenal function with respect to the androgen profile, and to carry out appropriate genetic studies.