OSFED — atypical anorexia and residual ED assessment (MEQ)

(i) Diagnosis and differentials. Most appropriate framing: OSFED — atypical anorexia nervosa. She meets AN psychopathology (restriction leading to significant weight loss, intense fear of weight regain, body image disturbance) but current weight is not in the significantly low range, so full AN is not coded. Full AN would require significantly low weight for age/sex/developmental trajectory. BN requires recurrent objective binge eating plus regular compensation at non-AN weight; she denies objective binges (twice-weekly vomiting alone without binge points toward purging within a restrictive atypical AN picture, or concurrent purging behaviours to document carefully — do not force BN). ARFID lacks shape/weight overvaluation and fear of fatness as the drive. Named OSFED example communicates residual reason; this is not “healthy weight” wellness.^[1][4]

(ii) Assessment priorities. Medical: quantify amount/rate of loss (18 kg / 8 months — high-risk trajectory); vitals (bradycardia 42, orthostasis) already signal instability; serial U&E including phosphate/magnesium/potassium, ECG, temperature, hydration; dental if purging; menstrual and bone-health history. Psychiatric: full suicide risk (passive death wishes), mood, exercise compulsion, food rules, trauma, substances; capacity and engagement; collateral from parents/coach myths. Formulation: large recent weight loss predicts complications independent of absolute BMI.^[1][2][5][6]

(iii) Management. Acute: medical stabilisation pathway now — bradycardia and orthostasis warrant urgent medical review/likely admission for monitoring and supervised refeeding with phosphate/electrolyte surveillance; do not reassure based on BMI 22.4. Parallel suicide risk management and safety planning. Definitive: nutritional rehabilitation toward individualised healthy trajectory; adolescent family-based elements (parent-supported renourishment, reduce accommodation of exercise/rules); CBT-E/transdiagnostic ED therapy for shape/weight overvaluation once medically safe enough for psychological work; GP–paediatric–psychiatry shared care. Medication is adjunctive only if indicated for comorbidity — not a substitute for renourishment and ED therapy.^[3][4][5]

(iv) Disposition and safety-net. Prefer medical admission or equivalent intensive monitoring given vitals; step down only after medical stability. Family psychoeducation: residual OSFED label does not mean mild; coach messages about “healthy weight” are harmful. Crisis contacts for worsening mood/suicidality; red-flag advice for syncope, further HR drop, purging escalation. Early outpatient review of weight trajectory, vitals, and binge/purge counts after discharge. Reassess diagnosis if weight falls into AN range.^[1][4][5]