FCPS Paediatrics TOACS · Interactive Station

✅ Candidate's answer:
• This is NOT a simple habit – it is a clinically significant Body-Focused Repetitive Behavior (BFRB).
• Factors indicating clinical significance:
1️⃣ Tissue damage – bleeding, infection of cuticles (beyond minor cosmetic concerns).
2️⃣ Multiple unsuccessful attempts to stop – bitter polish, willpower alone (she has tried).
3️⃣ Presence of premonitory urge and relief – tension before, relief/gratification after (characteristic of BFRBs).
4️⃣ Functional impairment – embarrassment, hiding hands, social avoidance.
5️⃣ Duration >2 years – chronic, not transient.
• DSM-5 classification: While nail biting alone does not have a specific code, this presentation could be diagnosed as Other Specified Obsessive-Compulsive and Related Disorder (Body-Focused Repetitive Behavior). It is distinct from trichotillomania (hair pulling) and excoriation (skin picking), but clinically similar.
• Differential includes habit (no distress/impairment) vs BFRB (distress, impairment, tissue damage).

✅ Candidate's answer:
• BFRBs: Repetitive, self-grooming behaviors that cause damage to the body. They are characterized by a premonitory urge before the behavior and relief or gratification during/after.
• Common BFRBs and DSM-5 classification:
- Trichotillomania (Hair-Pulling Disorder) – recurrent pulling out of one's hair, resulting in hair loss. DSM-5 diagnosis.
- Excoriation (Skin-Picking) Disorder – recurrent skin picking resulting in lesions. DSM-5 diagnosis.
- Onychophagia (Nail biting) – not a standalone diagnosis in DSM-5; classified under Other Specified Obsessive-Compulsive and Related Disorder (or Unspecified) if causing clinically significant distress/impairment.
- Cheek biting, lip biting, tongue chewing – also BFRBs.
• This patient has nail biting with tissue damage and functional impairment – meets criteria for a BFRB diagnosis.
• BFRBs are distinct from tics (no premonitory urge? – actually tics also have premonitory urges) and from OCD (no obsessions).

✅ Candidate's answer:
• Differential diagnosis:
1️⃣ Body-Focused Repetitive Behavior (BFRB) – repetitive grooming behavior; premonitory urge + relief; no obsession; ego-syntonic (feels "right" to do).
2️⃣ Tic disorders (Tourette, chronic motor tic) – sudden, rapid, recurrent, non-rhythmic movements (e.g., eye blinking, neck jerking). Premonitory urge also present. Tics are typically less focused on grooming and can involve vocalizations. Nail biting is not typically classified as a tic.
3️⃣ Obsessive-Compulsive Disorder (OCD) – repetitive behaviors (compulsions) performed to neutralize obsessions (e.g., fear of contamination). Compulsions are ego-dystonic (unwanted, resisted). No premonitory urge/relief cycle. Nail biting in OCD would be driven by an obsession (e.g., "my nails must be perfectly smooth") – not typical.
4️⃣ Stereotypic movement disorder – repetitive, rhythmic, purposeless movements (e.g., hand flapping, body rocking) in neurodevelopmental disorders. Not this.
5️⃣ Self-injurious behavior (non-suicidal self-injury) – intentional harm to cope with negative emotions, but different intent and context.
6️⃣ Habit (normal) – no tissue damage, no distress, no impairment.
• This patient's presentation (urge + relief, tissue damage, embarrassment) is most consistent with BFRB.

✅ Candidate's answer:
• Function of the behavior (triggers):
- "What feelings or situations make you bite your nails more?" (boredom, stress, anxiety, concentration).
- "Do you feel a tension or urge before biting?" (premonitory urge).
- "Do you feel relief during or after biting?"
- "Are you aware of the behavior while doing it?" (automatic vs focused).
• Comorbid psychiatric symptoms:
- Anxiety disorders – excessive worry, social anxiety (hiding hands).
- Depression – low mood, anhedonia.
- ADHD – impulsivity, difficulty stopping habits.
- OCD – other rituals, obsessions, compulsions.
- Tic disorders – other motor or vocal tics.
- Trichotillomania, excoriation – pulling hair, picking skin elsewhere.
• Family history: BFRBs, tics, OCD, anxiety.
• Past treatments: What worked? What failed? (bitter polish, fidget toys, rewards).
• Functional impact: School performance, social relationships (peers noticing), avoidance behaviors.
• Rule out organic causes: Neurologic exam (rule out tics, chorea, dystonia).

✅ Candidate's answer:
• Premonitory urge: An unpleasant bodily sensation, tension, or feeling that precedes and triggers the repetitive behavior (nail biting, tic, hair pulling, skin picking). The behavior is performed to relieve the urge.
• Characteristics:
- Patients describe it as "building tension" or "itch" that must be relieved.
- The behavior provides temporary relief or gratification.
- This distinguishes BFRBs/tic disorders from habits or OCD (where compulsions are driven by obsessions, not sensory urges).
• Importance in treatment:
- Habit Reversal Training (HRT) teaches the patient to recognize the premonitory urge and perform a competing response (an alternative behavior that is incompatible with nail biting) when the urge occurs.
- This is the first-line behavioral treatment for BFRBs and tics.
- This patient described urge before biting → good candidate for HRT.

✅ Candidate's answer:
• Habit Reversal Training (HRT) – evidence-based treatment for BFRBs and tic disorders.
• Key components (applied to nail biting):
1️⃣ Increased awareness (Response description and detection):
- Patient describes the nail-biting behavior in detail.
- Patient identifies each time the nail-biting occurs (self-monitoring).
2️⃣ Identifying premonitory urge:
- Patient recognizes the tension/urge that precedes biting.
- Early warning: "I feel my finger moving toward my mouth."
3️⃣ Competing response:
- Patient is taught an incompatible behavior to perform when the urge is felt.
- For nail biting: clench fists for 1-2 minutes, squeeze a stress ball, put hands in pockets, or press palms together until the urge passes.
- The competing response must be physically incompatible with nail biting.
4️⃣ Relaxation training: Deep breathing to reduce overall anxiety.
5️⃣ Social support: Parents/peers provide praise when competing response is used.
6️⃣ Generalization training: Practice in various situations (home, school, boredom, stress).
• Efficacy: HRT is highly effective (>70-80% reduction in symptoms) for BFRBs.
• This patient should be referred to a psychologist for HRT.

✅ Candidate's answer:
• Competing responses for nail biting:
1️⃣ Clench fists – squeeze tightly for 1 minute (cannot bite nails while clenching).
2️⃣ Place hands under thighs or in pockets.
3️⃣ Squeeze a stress ball or fidget toy.
4️⃣ Press palms together firmly.
5️⃣ Interlock fingers and rest them on the lap.
6️⃣ Hold a smooth stone or worry stone.
7️⃣ Apply bitter-tasting polish (as an adjunct, but not effective alone).
• Why physically incompatible? The competing response must physically prevent the nail-biting behavior. If the response is not incompatible (e.g., just thinking about not biting), it will not work. The muscle movement of the competing response substitutes for the habitual movement.
• The patient must practice the competing response multiple times daily when NOT biting, so it becomes automatic when the urge occurs.
• Duration: Competing response should be performed for 1-2 minutes or until the urge subsides.

✅ Candidate's answer:
• Why bitter polish failed (common):
- It targets the consequence (aversive taste) rather than the antecedent (premonitory urge).
- Many patients continue biting despite the taste, or they become desensitized to the taste over time.
- Does not address the underlying urge or provide a competing behavior.
• Is bitter polish ever helpful?
- May be useful as an adjunct to HRT (provides an extra deterrent).
- May work for mild, automatic nail biting (without premonitory urge) in younger children.
- For this patient (severe, with urge, tissue damage), bitter polish alone is insufficient – she needs HRT.
• Recommend using bitter polish together with HRT, not as a standalone treatment.

✅ Candidate's answer:
• No FDA-approved medications specifically for nail biting or BFRBs.
• Medications are used to treat comorbid conditions that may exacerbate nail biting:
- Anxiety disorders (GAD, social anxiety) – SSRIs (fluoxetine, sertraline) may reduce overall anxiety, which may reduce nail biting as a secondary effect.
- ADHD – stimulants may reduce impulsivity, but can worsen tics/BFRBs in some; alpha-agonists (guanfacine) may help.
- Tic disorders – alpha-agonists (guanfacine, clonidine) may reduce tics and BFRBs.
• N-acetylcysteine (NAC): An amino acid that has shown some benefit in trichotillomania and skin picking (small studies). Limited evidence for nail biting. Dose: 1200-2400 mg/day. May be tried as adjunct.
• Do NOT use benzodiazepines (risk of dependence) or antipsychotics unless severe tic disorder or aggression.
• This patient should first try HRT. If comorbid anxiety is present, treat the anxiety with CBT/SSRI; nail biting may improve as a secondary benefit.

✅ Candidate's answer:
• Paronychia management:
- Mild (no abscess): Warm soaks (2-3 times daily), topical antibiotic (mupirocin or bacitracin).
- Moderate (purulent discharge, erythema): Oral antibiotics (cephalexin or clindamycin) for 7-10 days. Cover for Staph and Strep.
- Abscess formation: Incision and drainage by a dermatologist or surgeon.
• Preventive measures:
- Moisturize cuticles with petroleum jelly or lotion to prevent cracking.
- Keep nails trimmed short (but not too short) to reduce temptation.
- Wear gloves or bandages on fingers to break the habit (temporary).
- Treat underlying BFRB with HRT to prevent recurrence.
• Consider dermatology referral if recurrent infections or severe tissue damage.
- Screen for immunocompromise (unlikely in this patient).

✅ Candidate's answer:
• Common comorbidities:
- Anxiety disorders (generalized anxiety, social anxiety) – 30-50% comorbidity.
- Depression – due to shame, embarrassment, social avoidance.
- OCD – some overlap, but distinct.
- ADHD – impulsivity contributes to difficulty stopping.
- Tic disorders – co-occurrence common.
- Trichotillomania, excoriation disorder – other BFRBs.
• Why screen?
- Untreated comorbidity (e.g., anxiety) may perpetuate the BFRB.
- Treatment of anxiety with CBT/SSRI may improve nail biting as secondary benefit.
- BFRB may be a marker for underlying emotional dysregulation.
- This patient should be screened using validated tools (PHQ-9 for depression, SCARED for anxiety, Vanderbilt for ADHD).

✅ Candidate's answer:
• Psychosocial impact of severe nail biting:
- Social embarrassment and shame – peers may tease or stare at the damaged nails.
- Avoidance behaviors – hiding hands, avoiding handshakes, wearing gloves or long sleeves in warm weather.
- Impaired self-esteem and body image.
- Academic impact – difficulty writing or typing if pain present; distraction in class.
- Social isolation – avoiding activities where hands are visible (sports, music, art).
- Family conflict – parents frustrated by inability to stop.
- Risk of depression and anxiety due to chronic shame.
• This patient's embarrassment and hiding hands indicate significant functional impairment.
• Intervention (HRT) can improve both the behavior and the psychosocial consequences.

✅ Candidate's structured answer:
• “I understand your frustration. Many parents ask the same question. Your daughter is not doing this on purpose to upset you.”
• “This is not just a bad habit. It is a condition called a Body-Focused Repetitive Behavior. She feels a building tension or urge before biting, and the biting temporarily relieves that urge. She has tried to stop but cannot on her own – that is part of the disorder.”
• “Blaming her or nagging her will not help and may increase her shame and anxiety, which can actually worsen the behavior.”
• “The good news is that there is an effective treatment called Habit Reversal Training. A therapist will teach her to recognize the urge and do a competing behavior (like clenching her fists) instead of biting.”
• “You can help by praising her when you see her using the competing behavior, and by creating a calm, low-stress environment. Do not punish her for biting – that only increases anxiety.”
• “We also need to treat any underlying anxiety or depression, which may be contributing. I will screen her for those conditions.”
• “With proper treatment, she can learn to control this. It is not her fault, and it is not a lack of willpower.”

✅ Candidate's answer:
• Refer to a mental health specialist (psychologist or psychiatrist) with experience in BFRBs and Habit Reversal Training.
• Indications for referral (this patient qualifies):
1️⃣ Severe tissue damage – bleeding, infection, significant physical harm.
2️⃣ Failed simple behavioral measures – bitter polish, parental reminders have failed.
3️⃣ Functional impairment – embarrassment, hiding hands, social avoidance.
4️⃣ Presence of premonitory urge and relief – indicates BFRB that requires HRT.
5️⃣ Possible comorbid psychiatric conditions – screen for anxiety, depression, tics, OCD.
6️⃣ Symptoms persisting >1 year despite attempts to stop.
• Can primary care manage? Primary care can:
- Provide initial education and reassurance.
- Screen for comorbidities.
- Treat medical complications (paronychia).
- Recommend over-the-counter deterrents (bitter polish) as a trial.
- But for severe cases with tissue damage and functional impairment, referral to a therapist for HRT is the standard of care.
- This patient needs referral to a psychologist for HRT.