First Presentation of Atypical Anorexia Nervosa in Asian Adolescents

Atypical Anorexia Nervosa (AAN) had been found to have significant physical and psychological complications at presentation but has not been described in a multi-ethnic Asian population. This retrospective cohort analysis aimed to characterize the baseline presentation of adolescents with Anorexia nervosa (AN) (N=317) and AAN (N=141) in an Asian cohort that presented to a specialist paediatric eating disorder program between January 2010 to October 2020 for assessment. In patients with AAN, there were increased proportions of males (16% vs 7%) and of Malay ethnicity (11% vs 4%) compared to AN. Adolescents with AAN had lower admission rates (61% vs 81%) as well as lower rates of bradycardia (45% vs 75%) and hypotension (7% vs 21%) but higher rate of syncope (13% vs 7%) compared to adolescents with AN. However, adolescents with AAN had higher frequency of psychological complications including self-harm and drug overdose (14% vs 1.5%) requiring admission as well as higher rates of purging (45.1% vs 14.8%) and for Eating Disorder Questionnaire score in the shape domain was more severe. Asian adolescents with AAN manifest with physical complications of malnutrition and had worse eating disorder psychopathology with higher frequency of other psychological co-morbidities underlining the severity of the illness.