Avoidant restrictive food intake disorder — formative SAQs

SAQ 1 — 13-year-old with sudden food refusal after a choking scare, falling weight (10 marks)

A 13-year-old boy has refused all solids for six weeks after choking on a piece of meat at a family dinner. He now takes only smoothies and milk and has lost 5 kg. He is anxious at the table and panics if solid food is offered. He is clear that he is not trying to lose weight and is upset about the weight he has lost. His BMI has dropped but remains above the 0.4th centile. He has no purging, no body-image concern, and no drive for thinness. [3] [1]

Questions

1. What is the most likely diagnosis, and what single boundary must you hold at this contact? Justify your reasoning. (3 marks) [2]
2. Outline your medical safety assessment and the red flags you must screen for. (3 marks) [3] [7]
3. Outline your stepwise management plan, naming the evidence-based therapy and its mechanism. (4 marks) [4] [6]

Model answer

Diagnosis and boundary (3). The most likely diagnosis is ARFID, fear or aversive subtype, triggered by the choking event — sudden onset, dated to an aversive trigger, anticipatory anxiety and panic at the table, restriction of whole food groups, and recent weight loss. The single boundary to hold is with anorexia nervosa: the absence of drive for thinness, fear of weight gain, body-image disturbance, purging, or compulsive exercise keeps this ARFID. State explicitly that some patients cross over, so you will screen for weight and shape overvaluation at every future contact. [2] [3]

Medical safety and red flags (3). Assess hydration status and ability to maintain fluids, screen for hypoglycaemia risk from near-zero intake, and plot serial weight and BMI to quantify the tempo of loss. Because he is low-weight, assess refeeding risk — he needs phosphate, magnesium and potassium surveillance and gradual nutritional restoration under local refeeding protocol if admitted, because refeeding syndrome is a preventable killer. Screen for an unsafe swallow and any organic driver hiding under a behaviour label, and an electrocardiogram is indicated if he is bradycardic or severely malnourished. Red flags that would mandate admission are dehydration, inability to maintain fluids, severe malnutrition with refeeding risk, or home-safety uncertainty. [3] [7]

Stepwise management (4). Medical safety first — stabilise and address refeeding risk before any therapy. Stop coercion and restore a calm meal structure of three meals and two to three snacks with no pressure tactics. Protect nutrition with dietetics — close the energy gap within accepted fluids and build toward tolerated textures, with oral nutritional supplements and, if truly necessary, enteral feeding only with an explicit exit plan. Deliver evidence-based therapy: cognitive-behavioural therapy for ARFID (CBT-AR), which for the fear subtype uses systematic desensitisation and graded, non-coercive exposure matched to the phobic mechanism — never forcing solids to prove they are safe, which would strengthen the phobia. Treat comorbid anxiety, involve the family without blame, and set shared functional goals. Escalate to intensive or inpatient care if outpatient fails or medical instability recurs, and build a relapse plan. [4] [6]

SAQ 2 — 8-year-old with autism, sensory selectivity and faltering growth (10 marks)

An 8-year-old boy with autism eats only six foods, all beige, from specific brands. If the packaging changes he will not eat. His weight has crossed two centiles down over a year. His mother has started force-feeding to get calories in, and mealtimes last ninety minutes and end in tears. He has no interest in losing weight and no body-image concern. [3] [8]

Questions

1. How do you classify this presentation, and what is your one-sentence problem representation? (3 marks) [2] [3]
2. What investigations are indicated, and which are low-value here? (3 marks) [3] [8]
3. Outline your management, including what you say to the mother about force-feeding tonight. (4 marks) [4] [5]

Model answer

Classification and problem representation (3). This is ARFID, sensory-based subtype, in an autistic child — extreme brand-specific selectivity, rigid sensory rules, distress when rules are violated, and faltering growth crossing two centiles, with no weight or shape overvaluation excluding anorexia nervosa. The problem representation is: "Eight-year-old with autism, six accepted brand-specific beige foods, weight crossing two centiles down over a year, ninety-minute coercive mealtimes, no body-image concern — ARFID sensory pattern with active nutritional and psychosocial domains, anorexia nervosa excluded." The line that separates ARFID from ordinary picky eating here is harm: faltering growth and collapsing family function, not parental annoyance. [2] [3]

Investigations (3). Order targeted bloods guided by the narrow diet and faltering growth — full blood count and iron studies, vitamin D, and micronutrients selected by diet pattern; in extreme sensory restriction add vitamin C (scurvy risk in autistic ARFID is documented), vitamin A and B12 where history suggests risk. Coeliac serology belongs if growth, stool or family history raises it. Plot serial growth on WHO-appropriate charts. A swallow assessment is indicated only if cough, wet voice or recurrent chest infection suggests unsafe swallow. Low-value and to be avoided: routine abdominal imaging, automatic long-term acid suppression without clear indication, endless allergy panels driven by parental fear, and repeated normal imaging that reinforces a disease model without changing management. [3] [8]

Management and the force-feeding conversation (4). Medical safety first — he is not currently in refeeding-risk territory but needs growth surveillance and a safety-net. The first prescription tonight is to stop force-feeding, because coercion amplifies the avoidance loop and worsens outcome; explain to the mother, without blame, that the ninety-minute battles are making the restriction worse and that stopping pressure is treatment, not giving up. Restore a calm meal structure of three meals and two to three snacks. Protect nutrition with dietetics — close the energy and micronutrient gaps within accepted foods first, with fortification and oral nutritional supplements. Deliver evidence-based therapy: CBT-AR with sensory-based graded exposure matched to his mechanism, or an FBT adaptation empowering the parents to lead non-coercive exposure at home; change one variable at a time and protect calories while expanding flexibility, with neurodiversity-affirming goals rather than a demand for a neurotypical plate. Treat comorbid anxiety, coordinate school and family support, and set shared functional goals — growth trajectory, variety, mealtime stress and school participation — not a perfect plate. [4] [5]