Pediatric Onychophagia: A Survey-Based Study of Prevalence, Etiologies, and Co-Morbidities

Onychophagia, defined as habitual nail biting, is a common disorder affecting 6-45% of the population and is more prevalent in children.

Our primary objective was to determine the prevalence of nail biting in the pediatric population. Secondary objectives were to assess the presence of psychiatric co-morbidities associated with nail biting, and the effect of treatment on nail biting.

An anonymous voluntary survey was administered to participants at an outpatient academic pediatric clinic at Weill Cornell Medicine. Age, sex, psychiatric diagnosis, treatment sought, family history, and frequency of nail biting were analyzed across 282 enrolled patients aged 3-21 years. One patient was subsequently excluded due to incomplete data.

Of 281 patients, 101 (37%) reported past or present nail biting lasting more than a month. Median age of onset was 5 years old (range 1-13 years). A significantly higher percentage of biters (18%; 19/104) than non-biters (6%; 11/177) were diagnosed with a psychiatric disorder (p < 0.01). Amongst biters, concurrent fingernail and toenail involvement was much less common (12%; 12/104) than that of fingernails alone (88%; 92/104). However, the ratio of fingernail and toenail biters to fingernail biters alone was greater in those with psychiatric diagnosis (0.36) than without (0.09) (p = 0.07).

Our study highlights behavioral patterns as well as familial, psychiatric, and other factors associated with pediatric nail biting. Familiarity with such factors, the clinical presentation of onychophagia, and available treatment options may aid in reducing its severity in affected patients and overall prevalence.