Enterocolitis
Answer: D.
As in any age range, melena typically denotes an upper gastrointestinal (GI) bleed (above the ligament of Treitz) or a slow-transit bleed anywhere in the GI tract, while hematochezia is typically caused by a lower GI bleed or possibly a massive or brisk upper GI bleed.
The etiology of lower GI bleeding varies greatly by age. In the neonatal period (first month), lower GI bleeding is a life-threatening disease until proven otherwise: the differential diagnosis includes malrotation with midgut volvulus, coagulopathy, necrotizing enterocolitis, sepsis, and Hirschprung disease. More benign etiologies include swallowing of maternal blood and anal fissures.
Out of the newborn period and up to two years the differential diagnosis includes the choices in the question stem as well as ano-rectal fissures, and lymphonodular hyperplasia (a self-limiting condition which thins the mucosa and causes hematochezia). Less common etiologies include arteriovenous malformations and tumors.
In preschool-age children, the main causes of lower GI bleeding are infection (viral, Shigella, Salmonella, Campylobacter, Yersinia, E. coli, C. difficile, among others) and juvenile polyps.
School-age children may have any of the above disorders seen in preschool-age children, but conditions such as inflammatory bowel disease enter the differential diagnosis at this age.
In this girl, her age range (infancy) includes both benign and dangerous etiologies.
Intussusception is the most common cause of obstruction in infants (B). Commonly there is abdominal pain (often children are woken from sleep), episodes of vomiting or irritability, or periods of somnolence. Bloody stools are a later finding. Ultrasonography is an excellent screening choice.
Hemolytic-uremic syndrome consists of a triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure (C). Risk factors include eating incompletely cooked ground beef, recent trip to a petting zoo, and visiting a resident in a nursing home with diarrhea. Typically there is a GI prodrome of up to a week of diarrhea, followed by bloody stools. Urine output may be reduced; up to a third of children may present with neurologic signs or symptoms such as irritability, seizure, or altered mental status. These children need critical care support with fluid resuscitation, correcting electrolyte abnormalities, and plasma exchange.
A Meckel diverticulum is a remnant of the omphalomesenteric duct (connection of the yolk sac to the intestine during embryo development). The cells lining the omphalomesenteric duct are pluripotent – if an island of these cells is trapped in a diverticulum, they may develop properties of gastric or pancreatic tissues, causing GI bleeding. Remember the rule of 2s: 2% of the population, 2% are symptomatic, 2 times more boys than girls, 2 types of ectopic tissue (gastric and pancreatic), most presentations under 2 years, 2 feet from ileocecal valve, 2 inches in length. A Meckel scan confirms the diagnosis.
Food protein-induced enterocolitis (also called milk-induced or soy-induced colitis) is an inflammatory reaction to ingested protein, either in breast milk or in formula. These children present well, with bloody stools – mothers will often relate that they wouldn’t have known anything was wrong “except for the bloody diaper”. The breast-feeding mother should eliminate all dairy from the diet (and potentially other allergens such as eggs, peanuts, shellfish, etc), including any products with additives such as casein or whey. Formula-fed infants may change to a formula with a higher whey:casein ratio (whey is much easier to digest), or avoid any dairy altogether and use a protein hydrosylated formula or amino acid-based formula (often not necessary and more expensive). After other dangerous etiologies have been considered and ruled out (mostly with a thorough history and physical – ancillary testing if appropriate), the child can be referred to his or her pediatrician to help the family sort out any feeding changes. In the ED, provide brief education, reassurance, anticipatory guidance, and close follow-up.
As in any age range, melena typically denotes an upper gastrointestinal (GI) bleed (above the ligament of Treitz) or a slow-transit bleed anywhere in the GI tract, while hematochezia is typically caused by a lower GI bleed or possibly a massive or brisk upper GI bleed.
The etiology of lower GI bleeding varies greatly by age. In the neonatal period (first month), lower GI bleeding is a life-threatening disease until proven otherwise: the differential diagnosis includes malrotation with midgut volvulus, coagulopathy, necrotizing enterocolitis, sepsis, and Hirschprung disease. More benign etiologies include swallowing of maternal blood and anal fissures.
Out of the newborn period and up to two years the differential diagnosis includes the choices in the question stem as well as ano-rectal fissures, and lymphonodular hyperplasia (a self-limiting condition which thins the mucosa and causes hematochezia). Less common etiologies include arteriovenous malformations and tumors.
In preschool-age children, the main causes of lower GI bleeding are infection (viral, Shigella, Salmonella, Campylobacter, Yersinia, E. coli, C. difficile, among others) and juvenile polyps.
School-age children may have any of the above disorders seen in preschool-age children, but conditions such as inflammatory bowel disease enter the differential diagnosis at this age.
In this girl, her age range (infancy) includes both benign and dangerous etiologies.
Intussusception is the most common cause of obstruction in infants (B). Commonly there is abdominal pain (often children are woken from sleep), episodes of vomiting or irritability, or periods of somnolence. Bloody stools are a later finding. Ultrasonography is an excellent screening choice.
Hemolytic-uremic syndrome consists of a triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure (C). Risk factors include eating incompletely cooked ground beef, recent trip to a petting zoo, and visiting a resident in a nursing home with diarrhea. Typically there is a GI prodrome of up to a week of diarrhea, followed by bloody stools. Urine output may be reduced; up to a third of children may present with neurologic signs or symptoms such as irritability, seizure, or altered mental status. These children need critical care support with fluid resuscitation, correcting electrolyte abnormalities, and plasma exchange.
A Meckel diverticulum is a remnant of the omphalomesenteric duct (connection of the yolk sac to the intestine during embryo development). The cells lining the omphalomesenteric duct are pluripotent – if an island of these cells is trapped in a diverticulum, they may develop properties of gastric or pancreatic tissues, causing GI bleeding. Remember the rule of 2s: 2% of the population, 2% are symptomatic, 2 times more boys than girls, 2 types of ectopic tissue (gastric and pancreatic), most presentations under 2 years, 2 feet from ileocecal valve, 2 inches in length. A Meckel scan confirms the diagnosis.
Food protein-induced enterocolitis (also called milk-induced or soy-induced colitis) is an inflammatory reaction to ingested protein, either in breast milk or in formula. These children present well, with bloody stools – mothers will often relate that they wouldn’t have known anything was wrong “except for the bloody diaper”. The breast-feeding mother should eliminate all dairy from the diet (and potentially other allergens such as eggs, peanuts, shellfish, etc), including any products with additives such as casein or whey. Formula-fed infants may change to a formula with a higher whey:casein ratio (whey is much easier to digest), or avoid any dairy altogether and use a protein hydrosylated formula or amino acid-based formula (often not necessary and more expensive). After other dangerous etiologies have been considered and ruled out (mostly with a thorough history and physical – ancillary testing if appropriate), the child can be referred to his or her pediatrician to help the family sort out any feeding changes. In the ED, provide brief education, reassurance, anticipatory guidance, and close follow-up.