What Is Trichoscopy?

Trichoscopy is a non-invasive diagnostic technique that uses a dermoscope (a handheld magnifier with a light source) to examine the scalp and hair shafts. Originally adapted from general dermoscopy for skin lesions, trichoscopy has become an essential tool for dermatologists and hair specialists. It enhances the ability to detect subtle features of hair and scalp diseases without the need for immediate biopsy.

How Does Trichoscopy Work?

• Equipment

  • A dermoscope with polarized or non-polarized light
  • Magnification typically ranging from 10× to 70×
  • Optional digital camera or smartphone adapter for image capture

• Procedure

  1. The patient’s hair is parted systematically to expose various areas of the scalp.
  2. The clinician places the dermoscope on the scalp surface—sometimes using a coupling fluid for better visualization.
  3. Key findings are observed in real time and can be photographed for monitoring over time.

What Can Trichoscopy Reveal?

Trichoscopy lets clinicians visualize microscopic changes in both the hair shaft and the scalp skin. Key observations include:

• Hair shaft abnormalities

  • Black dots (destroyed hairs in alopecia areata)
  • Yellow dots (dilated follicular ostia filled with keratin and sebum)
  • Exclamation‐mark hairs (narrowing at the proximal end seen in alopecia areata)
  • Broken hairs and flame hairs

• Scalp skin findings

  • Follicular openings (present in non‐scarring alopecias; absent in scarring types)
  • Perifollicular erythema or scaling
  • Vascular patterns (arborizing or red dots in conditions like discoid lupus)
  • Fibrotic white dots (sign of scarring alopecia)

Clinical Applications

Trichoscopy has transformed the evaluation of hair disorders by providing rapid clues to differentiate between conditions:

1. Alopecia Areata

   • Exclamation‐mark hairs, black dots, and yellow dots
   • Easy to spot early disease activity
   • Consider a free online symptom check for Alopecia Areata if you notice patchy hair loss

2. Androgenetic Alopecia (Male/Female Pattern Hair Loss)

   • Hair shaft miniaturization (variation in shaft diameter)
   • Brown peripilar signs (slight perifollicular pigmentation)

3. Telogen Effluvium

   • Uniform variation in hair shaft diameter without scarring or marked follicular changes
   • Increased empty follicular ostia

4. Scarring (Cicatricial) Alopecias

   • Absence of follicular openings
   • White or ivory areas indicating fibrosis
   • Specific vascular patterns (e.g., comma‐shaped vessels in lichen planopilaris)

5. Other Conditions

   • Tinea capitis: comma or corkscrew hairs
   • Trichotillomania: coiled hairs, broken shafts at different lengths
   • Psoriasis and seborrheic dermatitis: red dots, scaling, and pustules

Advantages of Trichoscopy

• Non‐invasive and painless
• Immediate real‐time results
• Ability to document and monitor progress with digital images
• Reduces the need for invasive scalp biopsies in many cases
• High patient acceptance and minimal preparation

Limitations and Considerations

• Operator Dependence
  Proper interpretation requires training and experience.
• Surface Evaluation
  Trichoscopy visualizes only superficial structures; deep pathology may still need a biopsy.
• Equipment Quality
  Higher magnification and digital capture tools enhance diagnostic accuracy but may increase cost.

Comparison with Other Non-Invasive Techniques

While trichoscopy focuses on hair and scalp, other fields use similar non-invasive imaging:

• Transient Elastography for liver stiffness (Castera et al. 2005)
• Hepatic Venous Pressure Gradient measurement (Bosch et al. 2009)

These hepatology tools, like trichoscopy, underscore the value of avoiding invasive procedures when possible.

Preparing for a Trichoscopy Appointment

• Wash and dry hair before your visit—avoid heavy styling products.
• Bring a history of hair loss, treatments tried, and any recent changes in health or stress.
• Discuss any medications you’re using, including topical solutions and supplements.

When to Seek Further Evaluation

Trichoscopy is highly informative, but certain “red‐flag” scenarios warrant urgent medical attention:

• Rapid, widespread hair loss over days
• Signs of infection (pain, swelling, fever)
• Scalp lesions that bleed, ooze, or fail to heal

Always speak to a doctor if you experience life‐threatening or serious symptoms.

Key Takeaways

• Trichoscopy is a safe, non-invasive way to examine hair and scalp disorders.
• It helps distinguish between different types of alopecia and scalp diseases.
• The technique reduces unnecessary biopsies and guides targeted treatment.
• If you notice patchy hair loss, consider a free online symptom check for Alopecia Areata.
• Always consult a healthcare professional for any serious or concerning symptoms.