What causes cleft lip and cleft palate, and what maternal factors contribute?
Both are developmental anomalies of the first branchial arch caused by multiple gene-environment interactions. Maternal factors: deficiency of B vitamins (B6, folate, B12), alcohol, smoking, diabetes, steroids/statins, hyperhomocysteinemia, gene mutations- all reduce neural crest mesenchyme that forms the embryonic face.
When do cleft lip and cleft palate each occur developmentally?
Cleft lip= incomplete fusion of the nasomedial or intermaxillary process during the 4th week of development. Cleft palate= incomplete fusion of primary palatal shelves during the 3rd month of gestation.
What are the treatment components for cleft lip/palate?
Surgical correction at 3-6 months, special feeding bottle, possible breastfeeding, orthodontic prosthesis, parental education and support, evaluation for hearing loss.
What is Meckel diverticulum and what are the Rules of Two?
Outpouching of all layers of the small intestinal wall (usually ileum)- most common congenital GI malformation. Rules of Two: 2 % of population, 2 % develop complications before 2, located within 2 feet of the ileocecal valve, averages 2 inches in length.
What causes Meckel diverticulum and what are its clinical manifestations?
Failure of the omphalomesenteric duct to obliterate (normally leaves a fibrous band connecting small intestine to umbilicus). Manifestations: usually asymptomatic; most common symptom= painless rectal bleeding. Treatment: surgical resection.
What is Hirschsprung disease, what causes it, and how does it present?
Obstruction of the colon- most common cause of colon obstruction in children. Caused by failure of neural crest cells to migrate into the GI tract- aganglionic skipped segments. Presents with delayed meconium passage, poor feeding, poor weight gain, abdominal distention. Treatment: surgical.
How does GER differ from GERD in infants, and why is reflux normal in newborns?
GER= normal in newborns because neuromuscular control of the gastroesophageal sphincter is not fully developed; infants usually outgrow it. GERD= persistnet reflux causing mucosal erosion, bleeding, dysphagia, or failure to thrive from ineffective protective mechanisms.
What is eosinophilic esophagitis and how is it differentiated from GERD?
Atopic disease involving immediate and delayed hypersensitivity reactions to food ingestion. Differentiated from GERD by presentation: dysphagia, food impaction, vomiting. Treatment: elimination diets and oral corticostreroids.
What is the treatment for pediatric GERD?
Thickened feedings, small/frequent feedings, prolonged feeding duration, slower flow rate, frequent burping and position changes, medications (increase motility, increase LES pressure, or decrease gastric acid). If no improvement: antireflux surgery (gastropexy and fundoplication- wrapping the fundus around the lower esophagus).
What is intussuception and what is the most common scenario?
Telescoping of one part of the intestine into anothe, causing obstruction. Most common: ileum invaginates into the cecum. Mesentery is constricted- venous stasis- engorgement- edema-exudation-further vascular compression-bleeding, necrosis, perforation, gangrene if untreated.
What are the classic clincal manifestations of intussuception?
Abdominal pain, irritable infant who flexes knees (colicky), vomiting shortly after pain onset, and currant jelly stools (dark, gelatinous- blood and mucus). Treatment: edema reduction; if unsuccessful, surgery. FATAL IF LEFT UNTREATED.
What is the classic triad of cystic fibrosis?
Deficiency of pancreatic enzymes, overproduction of vicous mucus in the respiratory tract, and abnormally elevated sodium and chloride concentrations (sweat chloride test).
How does cystic fibrosis affect the pancreas and what is the long-term consequence?
Thick mucus obstucts pancreatic ducts- blocks pancreatic enzyme flow- degenerative and fibrotic changes in the pancrease. Eventually damages beta cells- diabetes mellitus.
How is cystic fibrosis diagnosed and treated?
Diagnosis: 72- hour fecal fat measurements (determines extent of pancreatic function); sweat chloride test. Treatment: PERT (pancreatic enzyme replacement therapy), high-calorie/high-protein diet with frequent snacks and vitamin supplements, growth hormone, enteral supplements.
What is celiac disease and what is its pathophysiologic mechanism?
Autoimmune disease of the small intestinal villous epithelium triggered by gluten ingestion. T cell-mediated autoimmune injury to testinal epithelial cells- mucosal cell destruction with inflamation, atrophy, and flattening of villi in the upper small intestine.
What grains contain gluten?
Wheat, rye, barley, oats, and malt.
What are the clinical mainfestations of celiac disease?
Pale, bulky, greasy, foul-smelling stools; failure to thrive; malabsorption (rickets, bleeding, anemia, fat-soluable vitamin deficiencies); dehydration; protein loss; Mg/Ca malabsorption (irritability, tremor, convulsions, tetany, bone pain, dental abnormalities, osteomalacia); dermatitis herpetiformis (itchy blisters on elbows, knees, shoulders, back/buttocks midline).
How is celiac disease diagnosed?
Serologic antiendomysial and antitransglutaminase IgA antibodies + HLA-DQ2 or DQ8 typing (HLA class haplotypes that regulate immunity). Confirmed by duodenal biopsy showing classic mucosal changes.
What is the treatment for celiac disease and why is lactose initially excluded?
Immediately and permanently institute a gluten-free diet. Lactose is initially excluded because villous damage impairs lactose digestion; may be reintroduced after healing. Also supplement fat-soluable vitamins, iron, and folic acid.
Compare marasmus vs. kwashiorkor across age, cause and clinical findings.
Marasmus= deficiency of ALL nutrients; children < 1 year; lack of protein AND carbohydrates; metabolic processess preserved but growth severley retarded; muscle/fat wasting, anemia. Kwashiorkor= severe PROTEIN deficiencies; ages 1-4 years; weaned to high-starch, protein-deficient diet; generalized edema, dermatoses, hypopigmented hair, distended abdomen, hepatomegaly, NORMAL weight for age (due to edema).
What are the pathophysiologic mechanisms unique to kwashiorkor?
Inadequate dietary protein-leaky gut syndrome-intestinal inflammation-stored fat in liver-pancreatic atrophy/fibrosis.
What are the clinical manifestations of faltering growth (failure to thrive)?
Physical: delayed growth, pallid/dry/cracked skin, sparse hair, poorly developed musculature, decreased subcutaneous fat, swollen abdomen, diarrhea, anorexia, signs of vitamin deficiencies (rickets). Social/emotional: reduced energy/responsiveness, social isolation, spasticity when held, inability to make eye contact or smile, refusal to eat.
What is the threshold for diagnosing faltering growth on a growth curve?
Falls below the 3rd percentile on the growth curve OR shows stagnation in length or weight.
What is the leading cause of severe diarrhea in infants and young children worldwide?
Rotavirus. Treatment of acute infectious diarrhea: rehydration with fluids and electrolytes, maintain nutrition, treat associated conditions (antibiotics, antispasmodics, probiotics, IV solutions). Prevention: clean water, hygiene; sanitation, vaccines.
