Gastroenterology: Infantile colic; CMA; Threadworms Flashcards
Describe what is meant by infantile colic [1]
nfantile colic is characterised by paroxysms of persistent and uncontrollable crying in an otherwise healthy infant.
Explain the three possible aetiologies of infantile colic? [3]
Gastrointestinal aetiologies thought to be due to a disturbance in the gastrointestinal system. Proposed mechanisms leading to infantile colic include:
* Differences in gut microbiome, particularly alterations in Klebsiella species, anaerobic gram-negative bacteria, Escherichia coli and Lactobacillus species
* Increased intra-luminal gas due to unabsorbed carbohydrate fermentation by colonic bacteria
* Gastrointestinal dysmotility: notably intestinal hypermotility secondary to autonomic imbalance
* Visceral hypersensitivity: increase in pain signals from hypersensitive gut visceral pathways
Psychosocial aetiologies
There is an association between certain psychosocial factors in the parents and infantile colic, including:
* Stressful pregnancies and birth
* Post-partum depression
* Parental anxiety and depression, even paternal depression during pregnancy
* Lower parental education and intelligence
Biological aetiologies
* One of the theories that has been studied is that infantile colic may be the early manifestation of migraine, although studies have shown inconclusive results regarding this association
* Tobacco smoke and nicotine exposure, particularly during pregnancy or the post-partum period, is associated with a greater risk of developing infantile colic (twice as common)
* Elevated serotonin levels may play a role in infantile colic, where some studies have shown that urinary 5-OH IAA concentrations are greater in infants with colic compared to controls
What are the clinical features of infantile colic [+]
Infantile colic is characteristically described as paroxysms of uncontrollable crying in an infant less than three months old
- These episodes tend to occur early in the morning and in the evening within clusters
The cry in colic tends to be more severe than that of normal crying, for example the cry may be:
* Louder
* Higher in frequency
* Described as ‘screaming’ rather than crying
* More piercing/grating in nature
Other clinical features which may occur during the episodes of colic include:
* Facial flushing
* Tense abdomen
* Drawing up of legs to the abdomen
* Clenched fists
* Circumoral pallor
* Stiffening and tightening of arms
* Back arching
What is key to note about the presentation of infantile colic? [1]
Another important factor in infantile colic is the absence of red flag symptoms and signs. Infantile colic is generally a diagnosis of exclusion, as it occurs in an otherwise healthy infant. Usually an organic cause of crying is only found in approximately 10% of patients who present with excessive crying. Red flag features which must be absent include:
* Fever
* Evidence of diarrhoea, vomiting, abdominal distention
* Reduced conscious state e.g. lethargy, drowsiness, floppy
* Signs of trauma e.g. bruising, bleeding, fractures
* Poor feeding
* Poor weight gain and growth
* Signs of developmental delay
What are the ddx for infatile colic and how would you differentiate? [4]
Normal crying
Differences
* Normal crying is usually consolable by soothing, feeding, burping, or changing nappies (there is usually a discernible cause of crying)
* The crying in infantile colic tends to be louder, more ‘screaming’ in nature, of a higher pitch
Intussusception:
Differences
* Vomiting may be present
* Infants with intussusception may have diarrhoea, ‘red-currant jelly’ like stools or rectal bleeding
* The pathognomonic sign is an elongated mass in the right upper quadrant
Cow’s milk protein allergy
Differences
* Usually will have other symptoms such as vomiting, diarrhoea with blood/mucous, eczema
* May have poor weight gain and growth
* May have family history of milk protein allergy also
Gastro-oesophageal reflux disease
Differences
* May present with recurrent regurgitation of feeds after meals, often effortless and is worse when the infant lying down
* May have poor weight gain and growth
* In severe cases, may have haematemesis
How do you manage infantile colic? [3]
Caregiver education and support
- It is important to educate the caregiver on the benign and self-limiting nature of the condition, providing reassurance that the infant is not unwell and that it will spontaneously resolve by 3-5 months of age
- Reassure that is long term prognosis is excellent
Distraction techniques are excellent at helping
Appropriate feeding techniques
CBT and hypnotherapy can be useful
- Reduce brain-gut axis that drives it
Dietary changes not helpful.
Describe the classifications of cow’s milk protein intolerance/allergy (CMPI/CMPA) [2]
Both immediate (IgE mediated) and delayed (non-IgE mediated) reactions are seen.
- The term CMPA is usually used for immediate reactions and CMPI for mild-moderate delayed reactions.
Describe the GI symptoms of cow’s milk protein intolerance/allergy [5]
GI features:
Diarrhoea:
- This can be chronic and may contain blood or mucus. It is often associated with perianal redness.
Vomiting:
- This is typically regurgitation but can occasionally be projectile in nature.
Abdominal pain:
- Infants may show signs of discomfort such as crying and drawing up their legs. Older children may verbalise this symptom.
Faltering growth or failure to thrive:
- Due to malabsorption and loss of nutrients or decreased intake due to aversion to feeding.
Constipation:
- This can also be a feature, though less common than diarrhoea.
NB: While immediate IgE-mediated reactions (urticaria, angioedema, vomiting, wheezing) within 2 hours of ingestion are easier to recognise, non-IgE mediated reactions such as those involving the gastrointestinal tract may have a delayed onset up to 48 hours after ingestion making them more difficult to identify. Furthermore, some patients may experience mixed IgE and non-IgE mediated responses.
Describe the dermatological and respiratory features of cow’s milk protein intolerance / allergy [3]
Dermatological features
* Eczema: Particularly atopic eczema which may not respond well to standard treatments.
* Rash: Urticarial rash can occur which presents as transient wheals that are intensely itchy.
Respiratory features
* Asthma-like symptoms: Such as wheezing and coughing. These symptoms might not respond well to typical asthma treatment if they are caused by cow’s milk protein intolerance.
NB: While immediate IgE-mediated reactions (urticaria, angioedema, vomiting, wheezing) within 2 hours of ingestion are easier to recognise, non-IgE mediated reactions such as those involving the gastrointestinal tract may have a delayed onset up to 48 hours after ingestion making them more difficult to identify. Furthermore, some patients may experience mixed IgE and non-IgE mediated responses.
What are the first line investigations for CMA? [3]
Dietary Elimination and Reintroduction:
- The cornerstone of CMA diagnosis is the elimination of cow’s milk protein from the diet for 2-6 weeks, followed by a monitored reintroduction.
- If symptoms resolve during elimination and recur upon reintroduction, a diagnosis of CMA can be made.
Skin Prick Test (SPT):
- SPTs are useful for identifying IgE-mediated CMA.
- A positive result indicates sensitisation but does not confirm allergy. Therefore, it should be interpreted in conjunction with clinical history.
Specific IgE testing:
- This blood test measures levels of specific IgE antibodies to cow’s milk proteins. A higher level suggests greater likelihood of true allergy, however, like SPTs, it does not confirm allergy and must be interpreted in context.
If first-line investigations do not provide a clear answer or if non-IgE mediated CMA is suspected, which further investigations may be warranted? [3]
Dietary Elimination with Amino Acid-Based Formula (AAF): In cases where symptoms persist despite strict dietary elimination with extensively hydrolysed formula (eHF), an AAF trial may be necessary to confirm diagnosis.
Faecal Calprotectin: This stool test can help identify gastrointestinal inflammation associated with non-IgE mediated CMA. Elevated levels suggest inflammation but are not specific to CMA.
Endoscopy with Biopsies: In complex cases where diagnosis remains uncertain, endoscopic evaluation with biopsies may be considered. Histological findings can support a diagnosis of CMA, but are not diagnostic on their own.
What is the mx for CMA if formula fed [3] or breast-fed [3]
Management if formula-fed
* extensive hydrolysed formula (eHF) milk is the first-line replacement formula for infants with mild-moderate symptoms
* amino acid-based formula (AAF) in infants with severe CMPA or if no response to eHF
* around 10% of infants are also intolerant to soya milk
Management if breast-fed:
* continue breastfeeding
* eliminate cow’s milk protein from maternal diet. Consider prescribing calcium supplements for breastfeeding mothers whose babies have, or are suspected to have, CMPI, to prevent deficiency whilst they exclude dairy from their diet
* use eHF milk when breastfeeding stops, until 12 months of age and at least for 6 months
[] commonly known as threadworms, are small, white parasitic nematodes that primarily inhabit the human gastrointestinal tract.
Enterobius vermicularis, commonly known as threadworms, are small, white parasitic nematodes that primarily inhabit the human gastrointestinal tract.
Describe the features of threadworms infection [2]
Threadworm infestation is asymptomatic in around 90% of cases, possible features include:
* perianal itching, particularly at night
* girls may have vulval symptoms
How do you dx threadworms? [2]
Diagnosis may be made by the applying Sellotape to the perianal area and sending it to the laboratory for microscopy to see the eggs.
However, most patients are treated empirically and this approach is supported in theNICEguidelines.
Describe the pharmacological management of threadworms [2]
Mebendazole
- is recommended as a first-line treatment for all individuals aged over six months. A single dose should be given, followed by a repeat dose after two weeks if symptoms persist.
Piperazine with senna is an alternative for those who cannot tolerate mebendazole or for pregnant women in their second or third trimester.
What is the pathophysiology of Hirschprung’s disease [2]
parasympathetic neuroblasts fail to migrate from the neural crest to the distal colon → developmental failure of the parasympathetic Auerbach and Meissner plexuses → uncoordinated peristalsis → functional obstruction
Which populations is Hirschsprung’s disease most likely in? [2]
- 3 times more common in males
- Down’s syndrome
How would a neonate [1] compared to older children likely present with Hirschsprungs? [2]
neonatal period
- e.g. failure or delay to pass meconium
- vomiting
older children:
- constipation, abdominal distension
NB:
- The severity of the presentation and the age at diagnosis varies significantly depending on the individual and the extent of the bowel that is affected. It can present with acute intestinal obstruction shortly after birth or more gradually developing symptoms:
Describe what is meant by Hirschsprung-Associated Enterocolitis [1]
When does it occur in the life of a neonate? [1]
How does it present? [3]
What is there a risk of? [2]
Hirschsprung-associated enterocolitis (HAEC) is inflammation and obstruction of the intestine occurring in around 20% of neonates with Hirschsprung’s disease.
- It typically presents within 2-4 weeks of birth with fever, abdominal distention, diarrhoea (often with blood) and features of sepsis.
- It is life threatening and can lead to toxic megacolon and perforation of the bowel. It requires urgent antibiotics, fluid resuscitation and decompression of the obstructed bowel.
What is the Ix [2] and Mx [2] of Hirschsprungs?
Investigations
* abdominal x-ray
* rectal biopsy: gold standard for diagnosis
Management
* initially: rectal washouts/bowel irrigation
* definitive management: surgery to affected segment of the colon
