Random Dermatology MCQ - Trichotillomania

A 14-year-old girl presents with irregular patches of hair loss on the scalp, showing hairs of varying lengths. On close inspection, you notice broken hairs with blunt ends and no scaling or inflammation. The patient admits to frequently twisting and pulling her hair when stressed. Which of the following is the most likely diagnosis?

A) Alopecia areata
B) Trichotillomania
C) Tinea capitis
D) Telogen effluvium
E) Androgenetic alopecia

Correct Answer: B) Trichotillomania

Explanation

Key Features of Trichotillomania:

1. Clinical Presentation:

   • Patchy, irregular hair loss with preserved hair density at margins (unlike alopecia areata).

   • Broken hairs of varying lengths (due to repeated pulling).

   • Blunt-tipped fractured hairs (vs. exclamation mark hairs in alopecia areata).

   • No scaling or inflammation (rules out tinea capitis).

2. Behavioral Component:

   • Hair-pulling is compulsive, often triggered by stress/anxiety.

   • Patients may deny the behavior initially (diagnosis requires careful history).

3. Diagnostic Clues:

   • "Friar Tuck" pattern: Irregular bald patches with spared posterior scalp.

   • Perifollicular hemorrhage (seen on dermoscopy).

Why Not Other Options?

• (A) Alopecia areata: Smooth bald patches with exclamation mark hairs (tapered at scalp).

• (C) Tinea capitis: Scaling, inflammation, black-dot stubble (broken hairs with KOH+).

• (D) Telogen effluvium: Diffuse shedding, positive hair pull test (no broken hairs).

• (E) Androgenetic alopecia: Gradual thinning in patterned distribution (vertex/frontal).

Management:

• Behavioral therapy (habit reversal training).

• Cognitive-behavioral therapy (CBT) for underlying anxiety.

• N-acetylcysteine (NAC) may reduce urges (off-label use).

Prognosis: Chronic without intervention; early treatment improves outcomes.