Normative hair removal/manipulation. Trichotillomania should not be diagnosed when hair removal is performed solely for cosmetic reasons (i.e., to improve one’s physical ap- pearance). Many individuals twist and play with their hair, but this behavior does not usu- ally qualify for a diagnosis of trichotillomania. Some individuals may bite rather than pull hair; again, this does not qualify for a diagnosis of trichotillomania.
Other obsessive—compulsive and related disorders. Individuals with OCD and sym- metry concerns may pull out hairs as part of their symmetry rituals, and individuals with body dysmorphic disorder may remove body hair that they perceive as ugly, asymmetri- cal, or abnormal; in such cases a diagnosis of trichotillomania is not given. The description related disorder excludes individuals who meet diagnostic criteria for trichotillomania.
Neurodevelopmental disorders. In neurodevelopmental disorders, hair pulling may meet the definition of stereotypies (e.g., in stereotypic movement disorder). Tics (in tic dis- orders) rarely lead to hair pulling.
Psychotic disorder. Individuals with a psychotic disorder may remove hair in response to a delusion or hallucination. Trichotillomania is not diagnosed in such cases.
Another medical condition. Trichotillomania is not diagnosed if the hair pulling or hair loss is attributable to another medical condition (e.g., inﬂammation of the skin 01‘ other der- matological conditions). Other causes of scarring alopecia (e.g., alopecia areata, androgenic alopecia, telogen efﬂuvium) or nonscarring alopecia (e.g., chronic discoid lupus erythema- tosus, lichen planopilaris, central centrifugal cicatricial alopecia, pseudopelade, folliculitis decalvans, dissecting folliculitis, acne keloidalis nuchae) should be considered in individu- als with hair loss who deny hair pulling. Skirt biopsy or dermoscopy can be used to differ- entiate individuals with trichotillomania from those with dermatological disorders.
Substance-related disorders. Hair-pulling symptoms may be exacerbated by certain substances—for example, stimulants—but it is less likely that substances are the primary cause of persistent hair pulling.
Trichotillomania is often accompanied by other mental disorders, most commonly major depressive disorder and excoriation (skin-picking) disorder. Repetitive body-focused symptoms other than hair pulling or skin picking (e.g. nail biting) occur in the majority of individuals with trichotillomania and may deserve an additional diagnosis of other spec- ified obsessive-compulsive and related disorder (i.e., body-focused repetitive behavior disorder).
Diagnostic Criteria 698.4 (L98.1)
A. Recurrent skin picking resulting in skin lesions.
B. Repeated attempts to decrease or stop skin picking.
C. The skin picking causes clinically significant distress or impairment in social, occupa- tional, or other important areas of functioning.
D. The skin picking is not attributable to the physiological effects of a substance (e.g., co- caine) or another medical condition (e.g., scabies).
E. The skin picking is not better explained by symptoms of another mental disorder (e.g., delusions or tactile hallucinations in a psychotic disorder, attempts to improve a per- ceived detect or flaw in appearance in body dysmorphic disorder, stereotypies in ste- reotypic movement disorder, or intention to harm oneself in nonsuicidal self-injury).