Diabetes mellitus (DM) is a chronic metabolic disorder caused by an absolute or relative deficiency of insulin, an anabolic hormone. Insulin is produced by the beta cells of the islets of Langerhans located in the pancreas, and the absence, destruction, or other loss of these cells results in type 1 diabetes (insulin-dependent diabetes mellitus [IDDM]). Most children with diabetes have IDDM and a lifetime dependence on exogenous insulin.
Type 2 diabetes (non–insulin-dependent diabetes mellitus [NIDDM]) is a heterogeneous disorder. Most patients with NIDDM have insulin resistance, and their beta cells lack the ability to overcome this resistance. Although this form of diabetes was previously uncommon in children, in some, countries 20% or more of new patients with diabetes in childhood and adolescence have NIDDM, a change associated with increased rates of obesity. Other patients may have inherited disorders of insulin release leading to maturity onset diabetes of the young (MODY).
This chapter addresses only IDDM.
Pathophysiology
Insulin is essential to process carbohydrates, fat, and protein. Insulin reduces blood glucose levels by allowing glucose to enter muscle cells and by stimulating the conversion of glucose to glycogen (glycogenesis) as a carbohydrate store. Insulin also inhibits the release of stored glucose from liver glycogen (glycogenolysis) and slows the breakdown of fat to triglycerides, free fatty acids, and ketones. It also stimulates fat storage. Additionally, insulin inhibits the breakdown of protein and fat for glucose production (gluconeogenesis) in both liver and kidneys.
Hyperglycemia (ie, random blood glucose concentration more than 200 mg/dL or 11 mmol/L) results when insulin deficiency leads to uninhibited gluconeogenesis and prevents the use and storage of circulating glucose. The kidneys cannot reabsorb the excess glucose load, causing glycosuria, osmotic diuresis, thirst, and dehydration. Increased fat and protein breakdown leads to ketone production and weight loss. Without insulin, a child with IDDM wastes away and eventually dies from diabetic ketoacidosis (DKA).
An excess of insulin prevents the release of glucose into the circulation and results in hypoglycemia (blood glucose concentrations of <60 mg/dL or 3.5 mmol/L). Glucose is the sole energy source for erythrocytes, kidney medulla, and the brain.
Frequency
United States
Overall incidence is approximately 15 cases per 100,000 individuals annually and probably increasing. An estimated 3 children out of 1000 develop IDDM by age 20 years.
International
DM exhibits wide geographic variation in incidence and prevalence. Annual incidence varies from 0.61 cases per 100,000 persons in China, to 41.4 cases per 100,000 in Finland. Substantial variations exist between nearby countries with differing lifestyles, such as Estonia and Finland, and between genetically similar populations such as those in Iceland and Norway. Even more striking are the differences in incidence between mainland Italy (8.4/100,000) and the Island of Sardinia (36.9/100,000). These variations strongly support the importance of environmental factors in the development of IDDM. Most countries report that incidence rates have at least doubled or more in the last 20 years. Incidence appears to increase with distance from the equator.
Mortality/Morbidity
Information on mortality rates is difficult to ascertain without complete national registers of childhood diabetes, although age-specific mortality is probably double that of the general population. Particularly at risk are children aged 1-4 years who may die with DKA at the time of diagnosis. Adolescents are also a high-risk group. Most deaths result from delayed diagnosis or neglected treatment and subsequent cerebral edema during treatment for DKA, although untreated hypoglycemia also causes some deaths. Unexplained death during sleep may also occur.
IDDM complications are comprised of 3 major categories: acute complications, long-term complications, and complications caused by associated autoimmune diseases.
Acute complications reflect the difficulties of maintaining a balance between insulin therapy, dietary intake, and exercise. Acute complications include hypoglycemia, hyperglycemia, and DKA.
Long-term complications arise from the damaging effects of prolonged hyperglycemia and other metabolic consequences of insulin deficiency on various tissues. While long-term complications are rare in childhood, maintaining good control of diabetes is important to prevent complications from developing in later life. The likelihood of developing complications appears to depend on the interaction of factors such as metabolic control, genetic susceptibility, lifestyle (eg, smoking, diet, exercise), pubertal status, and gender.Long-term complications include the following:
Retinopathy
Cataracts
Hypertension
Progressive renal failure
Early coronary artery disease
Peripheral vascular disease
Neuropathy, both peripheral and autonomic
Increased risk of infection
Associated autoimmune diseases are common with IDDM, particularly in children who have the human leukocyte antigen DR3 (HLA-DR3). Some conditions may precede development of diabetes; others may develop later. As many as 20% of children with diabetes have thyroid autoantibodies.
Race
Different environmental effects on IDDM development complicate the influence of race, but racial differences clearly exist.
Whites have the highest reported incidence of IDDM; Chinese have the lowest.
IDDM is 1.5 times more likely to develop in American whites than in American blacks or Hispanics.
Current evidence suggests that when immigrants from an area with low incidence move to an area with higher incidence, their IDDM rates tend to increase toward the higher level.
Sex
The influence of sex varies with the overall incidence rates.
Males are at greater risk in regions of high incidence, particularly older males, whose incidence rates often show seasonal variation.
Females appear to be at a greater risk in low-incidence regions.
Age
Generally, incidence rates increase with age until mid-puberty then decline after puberty, but IDDM can occur at any age. Onset in the first year of life, though unusual, can occur and must be considered in any infant or toddler, because these children have the greatest risk for mortality if diagnosis is delayed. Their symptoms may include the following:
Severe monilial diaper/napkin rash
Unexplained malaise
Poor weight gain or weight loss
Increased thirst
Vomiting and dehydration, with a constantly wet napkin/diaper
Where prevalence rates are high, a bimodal variation of incidence has been reported that shows a definite peak in early childhood (ie, 4-6 y) and a second, much greater peak of incidence during early puberty (ie, 10-14 y).
Read further HERE
Showing posts with label Pediatrics. Show all posts
Showing posts with label Pediatrics. Show all posts
Thursday, 31 July 2008
Thursday, 29 May 2008
Social Phobia and Selective Mutism
Social phobia (social anxiety disorder) is the third most common mental health disorder after major depression and substance abuse, affecting approximately 10 million Americans, including children and adults. This disorder is defined by marked and persistent fear of social or performance situations in which embarrassment may occur; exposure to the social or performance situation almost always causes an anxiety reaction such as a situationally bound or situationally predisposed panic attack.
The anxiety reaction is not due to psychosis; individuals are able to recognize their fears as excessive and unreasonable. However, the ability to fully comprehend that the reaction is out of proportion to the precipitant may be less complete in children and may depend on their cognitive-developmental level of functioning.
The person's level of functioning (eg, ability to complete required educational, social, or family tasks) is significantly impaired, and the person may experience significant emotional distress (eg, dread, avoidance) as a response to social or performance situations. By definition, social phobia must persist for at least 6 months (in persons <18 y), must not be due to the direct physiological effects of a substance (eg, caffeine) or a general medical condition, and must not be better accounted for by another mental health disorder.
Often, social phobia can coexist with, or be the precursor to, agoraphobia. Agoraphobia is a specific phobia in which the individual fears being in crowded places. People with agoraphobia often become homebound.
Selective mutism is a disorder primarily affecting children, with some adolescents and adults who continue to experience an inability to speak in public. This inability is generally most disabling at school, as the child cannot be assertive and speak when called on by teachers. In adults, functional impairment occurs when public speaking or lecturing are required in one's vocation.
Formerly, selective mutism was called elective mutism in the Diagnostic and Statistical Manual of Mental Health Disorders, Third Edition (DSM-III), which was reflective of a previous view that the child intentionally refused to speak with others who are outside of the immediate family group. Often, the child with selective mutism designates a friend or close family member to serve as an interpreter of communication and whispers in that person's ear, so that communication occurs with the designated person as intermediary.
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Pathophysiology
Serotonin pathways may be involved in the mediation of the anxious and obsessive qualities of both social phobia and selective mutism. This theory is reinforced by animal models of phobic behavior and by response to commonly prescribed medications such as selective serotonin reuptake inhibitors (SSRIs), such as paroxetine, sertraline, or older heterocyclic-type antidepressants, such as Anafranil (clomipramine).
Frequency
United States
Social phobia is the third most common mental health disorder after depression. Lifetime prevalence ranges from 3-13%. Selective mutism is seen in fewer than 1% of children observed in mental health settings.
Mortality/Morbidity
No mortality occurs except with associated major depression resulting in suicide or reaction to medication treatment (sudden cardiac death with imipramine or clonidine) or adverse reaction such as newly onset suicidality to SSRIs or other antidepressants. A high morbidity rate is observed, with many missed school or workdays; the child often develops associated school refusal because of the anxiety associated with being asked to speak in class.
Age
Onset of social phobia may occur as early as school age but generally occurs by mid adolescence following a childhood history of social inhibition or excessive shyness. Often, onset is abrupt, occurring after a stressor or humiliating social experience.
Onset of selective mutism is typically when a child first attends school (either kindergarten or preschool) and, like social phobia, is often associated with an initial negative school experience, such as a stressor or humiliating social experience.
Read more HERE
The anxiety reaction is not due to psychosis; individuals are able to recognize their fears as excessive and unreasonable. However, the ability to fully comprehend that the reaction is out of proportion to the precipitant may be less complete in children and may depend on their cognitive-developmental level of functioning.
The person's level of functioning (eg, ability to complete required educational, social, or family tasks) is significantly impaired, and the person may experience significant emotional distress (eg, dread, avoidance) as a response to social or performance situations. By definition, social phobia must persist for at least 6 months (in persons <18 y), must not be due to the direct physiological effects of a substance (eg, caffeine) or a general medical condition, and must not be better accounted for by another mental health disorder.
Often, social phobia can coexist with, or be the precursor to, agoraphobia. Agoraphobia is a specific phobia in which the individual fears being in crowded places. People with agoraphobia often become homebound.
Selective mutism is a disorder primarily affecting children, with some adolescents and adults who continue to experience an inability to speak in public. This inability is generally most disabling at school, as the child cannot be assertive and speak when called on by teachers. In adults, functional impairment occurs when public speaking or lecturing are required in one's vocation.
Formerly, selective mutism was called elective mutism in the Diagnostic and Statistical Manual of Mental Health Disorders, Third Edition (DSM-III), which was reflective of a previous view that the child intentionally refused to speak with others who are outside of the immediate family group. Often, the child with selective mutism designates a friend or close family member to serve as an interpreter of communication and whispers in that person's ear, so that communication occurs with the designated person as intermediary.
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Pathophysiology
Serotonin pathways may be involved in the mediation of the anxious and obsessive qualities of both social phobia and selective mutism. This theory is reinforced by animal models of phobic behavior and by response to commonly prescribed medications such as selective serotonin reuptake inhibitors (SSRIs), such as paroxetine, sertraline, or older heterocyclic-type antidepressants, such as Anafranil (clomipramine).
Frequency
United States
Social phobia is the third most common mental health disorder after depression. Lifetime prevalence ranges from 3-13%. Selective mutism is seen in fewer than 1% of children observed in mental health settings.
Mortality/Morbidity
No mortality occurs except with associated major depression resulting in suicide or reaction to medication treatment (sudden cardiac death with imipramine or clonidine) or adverse reaction such as newly onset suicidality to SSRIs or other antidepressants. A high morbidity rate is observed, with many missed school or workdays; the child often develops associated school refusal because of the anxiety associated with being asked to speak in class.
Age
Onset of social phobia may occur as early as school age but generally occurs by mid adolescence following a childhood history of social inhibition or excessive shyness. Often, onset is abrupt, occurring after a stressor or humiliating social experience.
Onset of selective mutism is typically when a child first attends school (either kindergarten or preschool) and, like social phobia, is often associated with an initial negative school experience, such as a stressor or humiliating social experience.
Read more HERE
Monday, 26 May 2008
Gastrointestinal Duplications
Gastrointestinal duplications are rare congenital malformations that may vary greatly in presentation, size, location, and symptoms.
Problem
In 1733, Calder published the first report of an intestinal duplication. In 1937, Ladd introduced the term duplication of the alimentary tract. This condition consists of a group of congenital anomalies with the following 3 characteristics:
A well-developed coat of smooth muscle is present.
The epithelial lining represents some portion of the alimentary tract.
Duplications are frequently intimately attached to some portion of the gastrointestinal tract.
Frequency
Gastrointestinal duplications are observed in 1 of every 4500 autopsies, predominantly in white males. The small intestine is the most frequent site involved, whereas gastric, duodenal, rectal, and thoracoabdominal involvement is relatively rare. Synchronous gastrointestinal duplications occur in as many as 15% of patients.
Cervical duplications: Cervical esophageal duplication cysts are the most unusual gastrointestinal duplication, with fewer than 10 cases reported.
Thoracic and thoracoabdominal duplications: These make up 4% of all gastrointestinal duplications.
Gastric duplications: These duplications account for 7% of all gastrointestinal duplications.
Pyloric duplications: These are extremely rare. However, they are reported in the literature.1
Duodenal duplications: These account for 5% of all gastrointestinal duplications.
Small-intestine duplications: The small intestine is the most frequent site of gastrointestinal duplications, accounting for 44% of cases.
Colonic duplications: They may be cystic or tubular; colonic duplications represent 15% percent of duplications.
Rectal duplications: These represent up to 5% of gastrointestinal duplications.
Etiology
The true etiology of gastrointestinal tract duplications is not known. Several theories have been postulated. The idea that the initial developmental abnormality occurs in the gastrulation stage and results in a split notochord has been proposed. During early embryogenesis, the notochord is open, and the endoderm of the yolk sac and the ectoderm of the notochord are fused; a tube called the neuroenteric canal connects the yolk sac and the amnion. As part of the development of the split notochord, an endodermal-ectodermal adhesion between the cord has been proposed to result in the persistence of an endomesenchymal tract between the yolk sac and the amnion. The endomesenchymal tract formed is responsible for the anomalies of the entire gastrointestinal system. However, not all duplications are compatible with this theory, and other etiologies have been proposed.
Some duplications of the foregut and hindgut may occur as a result of "partial twinning." These duplications may be associated with other paired structures, such as those found in the genital and urinary tract. Other duplications, especially those of the ileum, may occur as a result of persistent embryological diverticula. Some portions of the intestinal tract have a solid stage during development; therefore, duplications of these structures may result from "aberrant luminal recanalization." Finally, intrauterine environmental factors, such as trauma or hypoxia during a vascular accident, may cause duplications at any level of the gastrointestinal tract.
Clinical
Presentation depends on the size and location of the duplication.
Cervical duplications: Patients with cervical duplications present with respiratory distress that may be life-threatening and requires rapid diagnosis and treatment.
Thoracic and thoracoabdominal duplications: Respiratory distress caused by airway compression may be noted in younger children; however, in older patients, heartburn or melena has been reported, which is probably caused by the presence of gastric mucosa in one third of patients with thoracic and thoracoabdominal duplications.
Gastric duplications: Patients usually present when younger than 1 year with vomiting, poor feeding, failure to gain weight, and a palpable mass upon physical examination. Hypertrophic pyloric stenosis is often a misdiagnosis in such infants. The mucosal lining of the cysts is often gastric and can lead to melena or hematemesis.
Duodenal duplications: Fifteen percent of these duplications contain ectopic gastric mucosa, which predisposes the patient to ulceration. Peptic ulceration may lead to painless gastrointestinal hemorrhage that can progress to perforation. Duplications may extend into the liver or even transdiaphragmatically. These are generally diagnosed after onset of high intestinal obstruction or hemorrhage that may commonly be accompanied by icterus or pancreatitis.
Small-intestine duplications: Clinical presentation depends on the type, size, location, and mucosal lining of the duplication. Small cystic duplications can be anchor points for intussusception or can result in volvulus, whereas long tubular duplications with proximal communication drain poorly, and retention of intestinal contents can obstruct adjacent intestine. Distal communication is more common and is more difficult to diagnose than proximal communication. Gastric mucosa in a duplication can lead to ulceration and perforation. The diagnosis is often not established before surgery.
Colonic duplications
Cystic colonic duplications are either asymptomatic or present as abdominal masses that may be accompanied by pain. Bleeding may be observed despite the lower prevalence of ectopic gastric mucosa in colon duplications. Newborns may present with volvulus or acute intestinal obstruction.
Tubular colonic duplications are usually asymptomatic, but severe esthetic problems are observed with the duplicated genitalia.
Rectal duplications: Presenting signs of colonic or presacral duplications may include constipation, rectal bleeding, hematochezia, rectal prolapse, hemorrhoids, fistula-in-ano, and perirectal abscess.
Read more HERE
Problem
In 1733, Calder published the first report of an intestinal duplication. In 1937, Ladd introduced the term duplication of the alimentary tract. This condition consists of a group of congenital anomalies with the following 3 characteristics:
A well-developed coat of smooth muscle is present.
The epithelial lining represents some portion of the alimentary tract.
Duplications are frequently intimately attached to some portion of the gastrointestinal tract.
Frequency
Gastrointestinal duplications are observed in 1 of every 4500 autopsies, predominantly in white males. The small intestine is the most frequent site involved, whereas gastric, duodenal, rectal, and thoracoabdominal involvement is relatively rare. Synchronous gastrointestinal duplications occur in as many as 15% of patients.
Cervical duplications: Cervical esophageal duplication cysts are the most unusual gastrointestinal duplication, with fewer than 10 cases reported.
Thoracic and thoracoabdominal duplications: These make up 4% of all gastrointestinal duplications.
Gastric duplications: These duplications account for 7% of all gastrointestinal duplications.
Pyloric duplications: These are extremely rare. However, they are reported in the literature.1
Duodenal duplications: These account for 5% of all gastrointestinal duplications.
Small-intestine duplications: The small intestine is the most frequent site of gastrointestinal duplications, accounting for 44% of cases.
Colonic duplications: They may be cystic or tubular; colonic duplications represent 15% percent of duplications.
Rectal duplications: These represent up to 5% of gastrointestinal duplications.
Etiology
The true etiology of gastrointestinal tract duplications is not known. Several theories have been postulated. The idea that the initial developmental abnormality occurs in the gastrulation stage and results in a split notochord has been proposed. During early embryogenesis, the notochord is open, and the endoderm of the yolk sac and the ectoderm of the notochord are fused; a tube called the neuroenteric canal connects the yolk sac and the amnion. As part of the development of the split notochord, an endodermal-ectodermal adhesion between the cord has been proposed to result in the persistence of an endomesenchymal tract between the yolk sac and the amnion. The endomesenchymal tract formed is responsible for the anomalies of the entire gastrointestinal system. However, not all duplications are compatible with this theory, and other etiologies have been proposed.
Some duplications of the foregut and hindgut may occur as a result of "partial twinning." These duplications may be associated with other paired structures, such as those found in the genital and urinary tract. Other duplications, especially those of the ileum, may occur as a result of persistent embryological diverticula. Some portions of the intestinal tract have a solid stage during development; therefore, duplications of these structures may result from "aberrant luminal recanalization." Finally, intrauterine environmental factors, such as trauma or hypoxia during a vascular accident, may cause duplications at any level of the gastrointestinal tract.
Clinical
Presentation depends on the size and location of the duplication.
Cervical duplications: Patients with cervical duplications present with respiratory distress that may be life-threatening and requires rapid diagnosis and treatment.
Thoracic and thoracoabdominal duplications: Respiratory distress caused by airway compression may be noted in younger children; however, in older patients, heartburn or melena has been reported, which is probably caused by the presence of gastric mucosa in one third of patients with thoracic and thoracoabdominal duplications.
Gastric duplications: Patients usually present when younger than 1 year with vomiting, poor feeding, failure to gain weight, and a palpable mass upon physical examination. Hypertrophic pyloric stenosis is often a misdiagnosis in such infants. The mucosal lining of the cysts is often gastric and can lead to melena or hematemesis.
Duodenal duplications: Fifteen percent of these duplications contain ectopic gastric mucosa, which predisposes the patient to ulceration. Peptic ulceration may lead to painless gastrointestinal hemorrhage that can progress to perforation. Duplications may extend into the liver or even transdiaphragmatically. These are generally diagnosed after onset of high intestinal obstruction or hemorrhage that may commonly be accompanied by icterus or pancreatitis.
Small-intestine duplications: Clinical presentation depends on the type, size, location, and mucosal lining of the duplication. Small cystic duplications can be anchor points for intussusception or can result in volvulus, whereas long tubular duplications with proximal communication drain poorly, and retention of intestinal contents can obstruct adjacent intestine. Distal communication is more common and is more difficult to diagnose than proximal communication. Gastric mucosa in a duplication can lead to ulceration and perforation. The diagnosis is often not established before surgery.
Colonic duplications
Cystic colonic duplications are either asymptomatic or present as abdominal masses that may be accompanied by pain. Bleeding may be observed despite the lower prevalence of ectopic gastric mucosa in colon duplications. Newborns may present with volvulus or acute intestinal obstruction.
Tubular colonic duplications are usually asymptomatic, but severe esthetic problems are observed with the duplicated genitalia.
Rectal duplications: Presenting signs of colonic or presacral duplications may include constipation, rectal bleeding, hematochezia, rectal prolapse, hemorrhoids, fistula-in-ano, and perirectal abscess.
Read more HERE
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