Pediatrics
Malabsorption
Paediatric malabsorption for NEET-PG: coeliac serology and biopsy, giardiasis, tropical sprue and abetalipoproteinaemia, mapped to NMC PE25.1.
MedNext Academy | 3 min read
Malabsorption
Paediatric malabsorption for NEET-PG: coeliac serology and biopsy, giardiasis, tropical sprue and abetalipoproteinaemia, mapped to NMC PE25.1.
This chapter covers the approach to malabsorption in children, anchored on coeliac disease serology and biopsy, and extending to giardiasis, tropical sprue, abetalipoproteinaemia, intestinal lymphangiectasia and short bowel syndrome. It emphasises growth monitoring and the red flags that separate benign toddler diarrhoea from organic disease.
High-yield: Malabsorption
- Coeliac disease must be diagnosed while the child is still eating gluten, starting with tissue transglutaminase IgA plus total IgA, before any move to endomysial antibody or biopsy.
- tTG-IgA is the most sensitive screening test at around 95 percent, while endomysial antibody IgA is the most specific at around 99 percent but is operator-dependent and expensive.
- Marsh 1, raised intraepithelial lymphocytes alone, is not diagnostic of coeliac disease by itself and also occurs in giardiasis, cow milk protein allergy, Crohn disease and H. pylori infection.
- The treatment of coeliac disease is a secure diagnosis followed by a lifelong gluten-free diet, and a gluten-free trial must not be started before testing because it erases the evidence.
- Dermatitis herpetiformis is the skin manifestation of gluten sensitivity, presenting as intensely pruritic grouped vesicles on extensor surfaces from IgA antibodies to epidermal transglutaminase.
- Stool ELISA for Giardia antigen is the preferred single test, whereas a saline wet-mount needs fresh warm stool examined within 30 minutes to preserve trophozoite motility.
- Giardiasis presents with intermittent bulky greasy offensive stools, no fever and no blood, often clustering among household members or classmates sharing water.
- A D-xylose test that is reduced points to mucosal disease such as coeliac disease or giardiasis, while a normal D-xylose with raised faecal fat points to a pancreatic or luminal cause.
- Abetalipoproteinaemia is a microsomal triglyceride transfer protein defect giving acanthocytes, cholesterol near zero and fat-soluble vitamin deficiency, treated with high-dose vitamin E.
- The intestinal lymphangiectasia triad is hypoalbuminaemia, lymphopenia and low immunoglobulins across all classes, with white villi seen on endoscopy.
- Tropical sprue should be suspected in a child from north-east India with chronic diarrhoea, megaloblastic anaemia and weight loss that does not improve on a gluten-free diet.
- Toddler diarrhoea is the commonest cause of chronic loose stools at 1 to 4 years, occurring in a thriving child with no blood, no nocturnal stools and undigested food in the stool.
- In chronic diarrhoea, preserved growth is the strongest reassurance, whereas crossing down weight or height centiles converts a stool complaint into an organic disease work-up.
- Short bowel syndrome prognosis depends on remnant small-bowel length, presence of the ileocaecal valve, colonic continuity and remnant mucosal health.
- Nocturnal diarrhoea, blood in stool, or fever with weight loss and night sweats are red flags for organic disease such as inflammatory bowel disease or intestinal tuberculosis.
Coeliac serology and biopsy traps
- **tTG-IgA:** Most sensitive screening antibody, about 95 percent; test with total IgA on a gluten-containing diet.
- **Endomysial antibody IgA:** Most specific antibody, about 99 percent, but operator-dependent and expensive.
- **Marsh 1:** Raised intraepithelial lymphocytes alone; not diagnostic without positive tTG-IgA.
- **D-xylose test:** Reduced in mucosal disease; normal with raised faecal fat suggests a pancreatic or luminal cause.
NMC competencies in this chapter
- **PE25.1:** Malabsorption in Children
Frequently Asked Questions
How is coeliac disease diagnosed in children?
It must be diagnosed while the child is still eating gluten. Start with tissue transglutaminase IgA plus total IgA, then use endomysial antibody or biopsy depending on the titre and pathway, and only commit to a lifelong gluten-free diet once the diagnosis is secure.
Which coeliac antibody is most sensitive and which is most specific?
tTG-IgA is the most sensitive screening test at about 95 percent, while endomysial antibody IgA is the most specific at about 99 percent. EMA is used to confirm weak-positive tTG results but is operator-dependent and expensive.
What is the best single test for Giardia?
Stool ELISA for Giardia antigen is the preferred single test. A saline wet-mount requires fresh warm stool examined within 30 minutes, since delay destroys trophozoite motility, and three samples on alternate days improve sensitivity.
What are the red flags for organic disease in chronic childhood diarrhoea?
Nocturnal diarrhoea, blood in stool, and fever with weight loss or night sweats point to organic disease such as inflammatory bowel disease or intestinal tuberculosis. Preserved growth is reassuring, while crossing down centiles demands a full work-up.
Continue reading
MBBSAll Pediatrics chapters
Continue through the Pediatrics chapter map.
Continue studying Pediatrics
Explore clinician-written learning resources, structured revision and practice across the MedNext platform.
Open in the MedNext appSee plans