Clinical characteristics and medical complications of pathologic
Brian L. Odlaug, B.A., Jon E. Grant, J.D., M.D., M.P.H.⁎
Department of Psychiatry, University of Minnesota School of Medicine, Minneapolis, MN 55454, USA
Received 25 June 2007; accepted 30 July 2007
Objective: This study sought to detail the phenomenology and medical consequences of pathologic skin picking (PSP).
Method: Sixty subjects (11.7% males) with PSP (mean±S.D.=33.7±11.6 years) were assessed. Subjects seen in a pharmacological study as
well as those from an ongoing outpatient longitudinal study comprised this sample. Subjects were assessed for current and lifetime
psychiatric comorbidity (using the Structured Clinical Interview for DSM-IV Axis I Disorders), clinical severity (using the Clinical Global
Impression — Severity scale) and psychosocial interference due to picking (using the Sheehan Disability Scale). Clinical characteristic data,
including time spent picking per day, sites picked and medical complications directly resulting from skin picking behavior, as well as family
history, were also obtained.
Results: The mean age (±S.D.) of onset for PSP was 12.3±9.6 years. The face was the most common area picked. Subjects reported picking a
mean of 107.6 min each day. Scarring, ulcerations and infections were common. Few had ever sought psychiatric treatment for their behavior.
Current comorbid Axis I psychiatric conditions were found in 38.3% of the sample. Trichotillomania (36.7%), compulsive nail biting
(26.7%), depressive disorder (16.7%) and obsessive–compulsive disorder (15%) were the most common current comorbid conditions.
Conclusion: PSP appears to be time consuming and frequently associated with medical complications. Research is needed to optimize
patient care for individuals with this behavior.
© 2008 Elsevier Inc. All rights reserved.
Keywords: Pathologic skin picking; Neurotic excoriation; Psychogenic excoriation
Pathologic skin picking (PSP), also referred to as neurotic
excoriation or psychogenic excoriation, is a condition
characterized by repetitive or compulsive picking of skin
to the point of causing tissue damage. Individuals suffering
from PSP report significant distress and psychosocial
impairment, including occupational and marital difficulties
[1–3]. Prevalence rates of PSP in the general population are
unknown, but studies have found that the behavior occurs in
4% of college students , 2% of dermatology patients [5,6],
11.8% of adolescent psychiatric inpatients  and 44.9% of
individuals with body dysmorphic disorder (BDD) .
Recent studies have also detailed the relationship between
PSP and obsessive–compulsive disorder (OCD), finding
elevated rates of PSP in patients with OCD and their first-
degree relatives [9,10]. The majority of individuals seeking
treatment for PSP are female .
Although PSP generally has its onset in adolescence, it
may occur at any age [4,12,13]. In fact, the onset of PSP
often begins with a dermatological condition such as acne,
eczema or psoriasis . The picking behavior may result
in significant tissue damage and scarring, sometimes even
warranting surgery , and, in rare cases, can be life
threatening . Individuals with PSP rarely seek derma-
tological or psychiatric treatment due to embarrassment 
or the mistaken belief that their condition is untreatable
. In a study of 31 patients with PSP, only 14 (45%) had
ever sought treatment and only 6 of the 31 had ever
received dermatological treatment despite the infections and
“deep craters” their picking behavior often resulted in .
Research on PSP has been limited by small sample sizes,
with little attention given to the medical consequences of
Available online at www.sciencedirect.com
General Hospital Psychiatry 30 (2008) 61–66
⁎Corresponding author. Tel.: +1 612 273 9736; fax: +1 612 273 9779.
E-mail address: email@example.com (J.E. Grant).
0163-8343/$ – see front matter © 2008 Elsevier Inc. All rights reserved.
picking behavior. Because there have been few systematic
studies of a series of rigorously diagnosed individuals with
PSP, the present study's purpose was to construct a detailed
demographic, phenomenological and medical picture of
individuals meeting proposed criteria for PSP. An under-
standing of the characteristics and medical problems of
individuals suffering from this behavior may have clinical
importance. Clinicians not only need to recognize the
emotional and psychosocial impact of picking to provide
appropriate mental health care but also need to be aware of
possible medical sequelae of picking so that appropriate
interventions may be made.
Sixty male and female outpatients, aged 17–63 years,
were recruited from a completed pharmacological treatment
study for PSP  and from an ongoing outpatient study
examining the longitudinal course of impulse control
disorders. Subjects for the pharmacological treatment
study (n=31) were recruited through newspaper advertising
and by posting flyers around the Minneapolis/Saint Paul
metro area. The outpatient study sample (n=29) was
recruited through flyers placed in a psychiatry clinic or
physician referral. No individuals refused to participate in
either study. Subjects were included in this database if they
met the general inclusion criteria, that is, if they (a) have a
primary diagnosis of current (past 12 months) PSP, (b) are
17 years or older and (c) could be interviewed in person.
The only exclusion criterion was the presence of an organic
mental disorder or inability to understand and consent to
by the following criteria (note: Criteria c and d have been
of trichotillomania and to limit more mild forms of picking
from being pathologized): (a) recurrent skin picking resulting
in noticeable tissue damage; (b) preoccupation with impulses
or urges to pick skin, which is experienced as intrusive;
(c) feelings of tension, anxiety or agitation immediately prior
to picking; (d) feelings of pleasure, relief or satisfaction while
picking; (e) the picking is not accounted for by another
medical or mental disorder (e.g., cocaine or amphetamine use
disorders, scabies); and (f) the individual suffers significant
distress or social or occupational impairment.
All research procedures were approved by the Institu-
tional Review Board of the University of Minnesota, and all
research subjects provided written informed consent prior
2.2.1. Clinical characteristics
All subjects underwent a semistructured interview to
assess clinical characteristics of the behavior. Clinical
questions assessed time spent picking per day, what
percentage of the time spent picking was conscious,
triggers to picking, sites of the body picked, whether the
subject picked anyone else's skin (i.e., proxy picking) and
whether the picking resulted in medical complications. All
clinical interviews were conducted by the same clinician
(J.E.G.) to ensure rating consistency and were done in an
2.2.2. Severity of PSP
Severity of picking was assessed using the Clinical
Global Impression (CGI) — Severity scale . The CGI
consists of a seven-item Likert scale used to assess severity
in clinical symptoms. Although not tested specifically in
PSP, the CGI has demonstrated excellent reliability and
validity in a wide range of psychiatric disorders. The
Severity scale of the CGI ranges from 1 (not ill at all) to 7
(among the most extremely ill).
In order to assess the overall psychosocial interference
due to picking, we included the Sheehan Disability Scale
(SDS) , a three-question self-report measure. The three
questions examine the degree to which picking interferes
with work/school, social life and family life/home respon-
sibilities. Each item uses an 11-point Likert scale with scores
ranging from 0 (no impairment) to 10 (extreme impairment).
Greater impairment is therefore defined by higher scores,
with total scores ranging from 0 to 30. The SDS was used in
only those subjects who consented to the pharmacological
treatment study (n=31) .
2.2.3. Comorbid psychiatric disorders
Each subject underwent the Structured Clinical Interview
for DSM-IV Axis I Disorders (SCID-I) , which was
administered by one clinician (J.E.G.), to assess current and
lifetime comorbid disorders, and SCID-compatible modules
were used to examine current and lifetime rates of impulse
control disorders (pathologic gambling, trichotillomania,
kleptomania, pyromania, intermittent explosive disorder,
compulsive buying and compulsive sexual behavior).
2.2.4. Family history
Each subject underwent a semistructured interview using
the SCID-I and SCID-compatible modules  to examine
psychiatric disorders, including impulse control disorders,
PSP and hair pulling, in first-degree relatives. All psychiatric
disorders that were included for the subject were also
included in this interview. No relatives were interviewed
directly for this study.
Sixty consecutive subjects [n=7 (11.7%) males] with
current PSP were studied. At the time of presentation,
the age of the 60 subjects ranged from 17 to 63 years
(mean±S.D.=33.7±11.6). The sample included 55 (91.7%)
62 B.L. Odlaug, J.E. Grant / General Hospital Psychiatry 30 (2008) 61–66
Caucasians, 3 (5.0%) Asian Americans and 2 (3.3%)
Of the 60 subjects with PSP, 13 (21.7%) were high school
graduates, 10 (16.6%) had some college or trade school
education, 28 (46.7%) were college graduates and 9 (15.0)
had pursued education beyond college. Thirty-two (53.3%)
were single, 25 (41.7%) were married and 3 (5.0%) were
divorced or separated.
3.2. Clinical characteristics
The clinical characteristics are presented in Table 1. The
reported mean age (±S.D.) of onset of PSP was 12.3±9.6
years (range=3–49). Individuals picked with full awareness
of their behavior the majority of time (78.1%), and clear
triggers, such as the sight or feel of the skin, usually
precipitated the picking.
The face was the area most commonly picked, and face
picking resulted in significant distress and embarrassment
because of the difficulty hiding the tissue damage. The
majority of subjects (68.8%) picked from more than one area
and often reported that they would switch areas in order to
allow an area to heal.
Subjects were generally quite ill. Subjects reported
picking a mean (±S.D.) of 107.6±108.7 min each day, with
some subjects spending 6–8 h each day. Mean (±S.D.) CGI
scores (4.7±0.9) denote marked severity of illness. The level
of social and occupational dysfunction (as reflected in the
SDS scores), however, was only mild in severity (12.1±6.3).
Table 2 summarizes comorbidity results for Axis I
disorders. Twenty-three (38.3%) subjects reported symptoms
consistent with a current Axis I disorder, and 34 (56.7%)
reported at least one lifetime Axis I disorder. Although
trichotillomania was the most common current and lifetime
comorbid disorder (36.7% and 38.3%, respectively), comor-
bidity with other impulse control disorders was infrequent
(1.6% current and 3.3% lifetime). Comorbid OCD was fairly
common (15.0% current and 16.7% lifetime), but a similar
disorder, BDD, was uncommon in this sample (5.0% current
and 5.0% lifetime).
3.4. Family history
Twenty-four subjects (40.0%) had at least one first-degree
relative with a psychiatric disorder. The most common were
the following: 17 (28.3%) reported having at least one first-
degree relative with picking behavior, 12 (20.0%) reported at
Clinical characteristics, family history and psychiatric comorbidity of
60 individuals with PSP
Age of onset (years), mean (±S.D.)
Time spent picking per day (min),
mean (±S.D.) [range]
Percentage of total picking time
that was conscious,
mean (±S.D.) [range]
Triggers to picking, n (%)
Sites picked, n (%)
Number of sites picked,
mean (±S.D.) [range]
No. of places picked, n (%)
Items used to pick skin
Picks other people's skin, n (%)
Previously sought treatment
for picking, n (%)
CGI severity, mean (±S.D.)
SDS (n=31), mean (±S.D.) [range]
At least one first-degree
family member with:
PSP, n (%)
Trichotillomania, n (%)
Subjects with at least one
first-degree family member
with either trichotillomania or PSP, n (%)
107.6 (108.7) [20–480]
78.1 (27.0) [10–100]
2.28 (1.21) [1–7]
12.1 (6.3) [0–28]
Current and lifetime psychiatric comorbidity of 60 individuals with PSP
Comorbid disordersCurrent, n (%)Lifetime, n (%)
Major depressive disorder
Depressive disorder NOS
Any bipolar spectrum disorder
Any substance use disorder
Any somatoform disorder
Any impulse control disorder
Compulsive nail biting
Any eating disorder
Any psychotic disorder
Any current comorbid disorder
63B.L. Odlaug, J.E. Grant / General Hospital Psychiatry 30 (2008) 61–66
least one relative with a substance use disorder and 11
(18.3%) reported a relative suffering from depression.
3.5. Medical consequences
Table 3 presents the medical consequences of PSP. All
subjects had noticeable excoriations, and 17 (28.3%) had
more severe ulcerations, at the initial visit. Scarring from
previous picking was noted in 27 (45.0%) subjects. Scarring
and ulcerations ultimately led 7 (25.9%) of those with
scarring to undergo laser therapy or dermabrasion for
cosmetic reasons. Although the majority of subjects used
their fingernails to pick, 17 (28.3%) used tweezers and 8
(13.3%) used knives or pins to pick. None of the subjects
who used these utensils sterilized them prior to use.
Infections from picking were not uncommon. In fact, 35%
of subjects had experienced an infection that required oral,
topical or intravenous antibiotics. In the most severe cases,
two subjects required skin grafting due to their inability to
stop picking. Both cases of skin grafting required multiple
grafts because the subjects could not stop picking the area of
To our knowledge, this is the first study to examine the
clinical characteristics and medical complications of a large
sample of individuals suffering from PSP. This is also a
fairly broad sample of individuals with this disorder (our
study had very broad inclusion/exclusion criteria), which
may increase the generalizability of the results. The results
demonstrate that PSP is a pathologic behavior that is time
consuming, causes significant distress and often leads to
serious medical complications.
PSP is currently classified in DSM-IV-TR as an “impulse
control disorder not otherwise specified” . Although
there exists some controversy regarding the most precise
categorization of this behavior, this study's comorbidity data
support a possible link between PSP and trichotillomania
and compulsive nail biting but not other impulse control
disorders such as pathologic gambling or kleptomania.
Rates of trichotillomania in this study (38.3% lifetime and
36.7% current) are notably higher than rates found in the
general population (1.0–2.5%) [22,23]. Similarly, nail
biting was common in this study (current rate of 26.7%
and lifetime rate of 31.7%), with rates much higher than the
6.4% current prevalence rate found in one study of college
Although PSP has clear similarities to trichotillomania
and nail biting , its relationship to other obsessive–
compulsive spectrum disorders remains unclear. Studies of
OCD have consistently found elevated rates of comorbid
PSP among subjects with OCD [25–29], and there has been
evidence of a possible genetic link between PSP and
subgroups of OCD [9,10,30]. This study found that rates of
OCD were seven to eight times greater in PSP than in the
population at large (2–3%) [31,32], further supporting a
link between these disorders. The relationship of PSP to
BDD (a disorder with phenomenological links to OCD)
appears more complicated. A previous study found that
almost one half (44.9%) of BDD subjects engage in skin-
picking behavior at some point in their lives . Rates of
BDD in this sample of PSP subjects, however, were only
5% for both current and lifetime comorbidity. This raises
questions of whether picking behavior may be a symptom
of multiple disorders and whether different neurobiological
and genetic underpinning may all give rise to the symptom
of repetitive picking.
This study found that medical complications are frequent
in individuals with PSP. Approximately one third of subjects
required antibiotic treatment due to their picking. This
finding suggests that clinicians should carefully screen for
picking behavior as patients are unlikely to volunteer the
information without being asked. In addition, when picking
is acknowledged, clinicians must perform physical examina-
tions of their patients to assess the extent and severity of
picking. Infections often go unnoticed and untreated when
the picking is not restricted to the face. When picking is
severe, appropriate referrals and collaboration with medical
internists may be warranted.
One health concern with these subjects, however, is that
the longitudinal course of PSP remains unknown. There-
fore, there is the possibility that those who have not yet
caused ulcerations or needed antibiotic treatment may
require such treatment in the future. In fact, many of the
subjects reported that their picking behavior had initially
been less frequent but that the intensity and frequency of
their behavior had increased over time. In such a small
sample, however, a thorough understanding of the course of
PSP is not possible. These findings emphasize the
importance of studying the course of PSP in order to
optimize prevention and treatment strategies.
This study suffers from several limitations. First, this
sample was composed only of individuals seeking treatment
Medical consequences of PSP
Medical consequencen (%)
Linear erosions/excoriations from picking
noticeable on examination
Ulcerations from picking noticeable
Notable scarring due to tissue damage
Underwent laser therapy or
dermabrasion for scarringa
Required oral or topical antibiotic treatment
due to infection from picking
Required intravenous antibiotic treatment
due to bacteremia/septicemia from picking
Required skin grafts due to tissue damage
aOf the 27 subjects who had scarring
64 B.L. Odlaug, J.E. Grant / General Hospital Psychiatry 30 (2008) 61–66
(either therapy or medication). The extent to which these
results generalize to the larger population of people with PSP
warrants future study. Future studies using a control group of
patients with a range of psychiatric disorders would be useful
in determining if comorbid psychiatric illness is more
prevalent in the PSP population. Second, the medical
information was gathered retrospectively with no corrobora-
tion from medical records. Therefore, this information may
suffer from possible recall bias and underestimation of
medical complications. Third, although subjects were asked
extensively about family history, no interviews were
conducted with family members and no control groups
were used. Nonetheless, the inclusion/exclusion criteria of
the study were fairly broad (inclusion of those who did or did
not meet criteria for treatment studies) and used both self-
report and interviewer-administered measures with strong
Large phenomenological studies are needed to elucidate
the clinical characteristics, course and medical complications
of PSP. As promising advances have been made in the
treatment of PSP [16,33,34], early detection and intervention
are imperative. Just as research has provided greater
information on the neurobiology and treatment of other
psychiatric disorders, neuroimaging, genetics and clinical
trials will be needed to identify the pathophysiology of, and
treatment for, this behavior.
This research was supported in part by a Career
Development Award (K23 MH069754-01A1) to Dr. Grant
and by NIDA (R01 DA019039). Part of this research sample
was also supported by an unrestricted educational grant from
GlaxoSmithKline to Dr. Grant. Dr. Grant received no
honorarium and does not have any other financial interest
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