Trichoscopy, which is based on dermoscopy, can be a valuable tool for diagnosing conditions that cause hair loss and inflammatory scalp disease.
Trichoscopy, a method of hair and scalp evaluation based on dermoscopy, is an essential tool in the dermatologist armamentarium for diagnosis of causes of hair loss, rare genetic hair shaft abnormalities, and inflammatory scalp diseases.
In a presentation at the American Academy of Dermatology Virtual Meeting Experience 2021 in April, Lidia Rudnicka, MD, PhD; Anna Waśkiel-Burnat, MD, PhD; Sergio Vañó-Galván, MD, PhD; and Bianca Marie Piraccini, MD, discussed best-practice recommendations for using trichoscopy as an aid in hair and scalp diagnosis and treatment.1
Rudnicka, a professor and chairman of the department of dermatology at Warsaw Medical University in Poland, discussed the 7 distinct ways to spot trichotillomania in patients with hair loss.2
Trichotillomania, a mental disorder classified under the obsessive-compulsive umbrella, involves “the recurrent and irresistible urge to pull hair from the scalp, eyebrows, eyelashes, and other body areas,” she said.
Rudnicka listed tips for diagnosing the disorder:
1. Look for evidence of hook hairs, categorized by hairs with a distal end shaped like a hook, due to its high link to the mental disorder. “If we see a field of view with multiple hook hairs, we can be almost sure this is trichotillomania because the hook hairs have a 100% positive predictive score,” she said.
2. Check for the presence of coiled hairs, seen to be irregular in shape with a jagged end. This is not to be confused with circle/pigtail hairs seen in alopecia areata, which are regular in shape with a sharp distal end.
3. Watch for V-sign hairs from a patient pulling 2 or more hairs from 1 follicle unit. An indication of the disorder, they are formed from creating breakage in similar areas of the strands.
4. Monitor the patient for trichoptilosis, which are young short hairs with split ends.
5. Examine patients for flame hairs, which is hair residue that is semitransparent, wavy, and thinning toward the distal end.
6. Watch for hair powder, which is even more dispersed participles of hair residue.
7. Identify any sign of tulip hair, which develops when a hair is broken diagonally and gives the impression of distal hyperpigmentation in the shape of a tulip head.
Rudnicka also highlighted the lesser-known trichotillomania incognito.
“This is a case of a person who has almost normal-looking hair but complains of a tendency of hair that has stopped growing,” she said. “[With] trichoscopy, you will see very discreet features of trichotillomania.”
Inflammatory Scalp Diseases
Waśkiel-Burnat, a clinician at the department of dermatology at the Medical University of Warsaw, discussed the differentiating features of inflammatory scalp diseases using trichoscopy.3
Using 4 cases of scalp diseases that presented with similar symptoms, she highlighted key ways to distinguish the diseases.
In her first example, Waśkiel-Burnat diagnosed mycosis fungoides through the presence of pili torti (hair with a twisted hair shaft), 8-shaped hair (resembling a number 8), white scaling, and perifollicular arrangement of linear and glomerular vessels.
In another case, seborrheic dermatitis presented with symptoms consisting of yellow and whitish scaling and arborizing vessels, which are commonly observed in these patients, she said.
A third example of psoriasis showed signs of white scaling, glomerular vessels, and punctate hemorrhages. And lastly, a patient with dermatomyositis showed evidence of enlarged tortuous capillaries, bushy capillaries, and interfollicular and perifollicular scaling.
Highlighting the main trichoscopic features of lichen planopilaris (LPP), Vañó-Galván, head of the trichology unit at Ramón y Cajal Hospital in Madrid, Spain, discussed the difference between active lesions and inactive lesions. He included other features such as pili torti, blue gray dots in a target pattern, and broken hairs.4
Active lesions can be distinguished by perifollicular scaling and peripilar casts. According to Vañó-Galván, these scales migrate along the hair shaft and form a tubular structure that covers the proximal portion of the emerging hair shaft. This is believed to occur due to changes in the outer hair follicle root sheath, he said.
Elongated linear blood vessels are another indicator of active LPP lesions. These vessels form a V with the corresponding emerging hair shaft. Violaceous follicular erythema is additional evidence of this, according to Vañó-Galván.
Inactive lesions on the other hand have irregular, large white dots, white or milky red areas, and tufted hairs.
Piraccini, an associate professor in the department of specialized experimental and diagnostic medicine in the Alma Mater Studiorum at the University of Bologna, Italy, uses trichoscopy not only as a diagnostic tool but also to grade severity, diagnose associated diseases, and monitor treatment outcomes for androgenetic alopecia.5
She uses the tool in mostly the anterior/vertex/temples where there are androgen-sensitive hair follicles and the occipital area where hair follicles are not as sensitive to androgens.
Androgenetic alopecia trichoscopy signs include reduced hair thickness with an increased number of hairs with the diameter of less than 3 mm, empty follicles, reduced number of hairs per pilosebaceous unit, and peripilar halos, according to Piraccini. Thinning is especially evident in the frontal area because of hair follicle miniaturization, she said.
She monitors treatment outcomes through trichoscopy as a clear and easy way for patients to understand the indicators of increased hair density and health.
“I follow the patient every 6 months, and after the first 6 months trichoscopy shows improvement,” Piraccini said. “I show the patient the positive outcomes in the number of hairs and the thickness.”
Trichoscopy, as presented by the 4 experts, plays an essential role for diagnosing hair or scalp disease, and showcases the ease of treatment monitorization.
Rudnicka and Waśkiel-Burnat reported no relevant financial disclosures. Vañó-Galván is a speaker and adviser for Almirall, Cantabria Labs, Laboratoires Pierre Fabre-Ducray, and L’Oréal. He is a speaker for Novartis International AG, GlaxoSmithKline, Merck & Co, and Galderma; he is an adviser for Pfizer Inc, Janssen Pharmaceuticals, and Isdin. He has received research funding from Novartis International AG, Cantabria Labs, Fagron, and DS Pharma. Piraccini disclosed industry relationships with Laboratoires Pierre Fabre-Ducray, Legacy Healthcare, Pfizer Inc, Almirall, Difa Cooper, and Dercos L’Oréal.
1. Rudnicka L, Waśkiel-Burnat A, Vañó-Galván S, Piraccini B. Trichoscopy: an update. American Academy of Dermatology Virtual Meeting Experience 2021; April 23-25, 2021; virtual. Accessed May 7, 2021.
2. Rudnicka L. Trichoscopy of trichotillomania. American Academy of Dermatology Virtual Meeting Experience 2021; April 23-25, 2021; virtual. Accessed May 7, 2021.
3. Waśkiel-Burnat A. Trichoscopy cases of inflammatory scalp diseases. American Academy of Dermatology Virtual Meeting Experience 202; April 23-25, 2021; virtual. Accessed May 7, 2021.
4. Vañó-Galván S. Trichoscopy of lichen planopilaris. American Academy of Dermatology Virtual Meeting Experience 2021; April 23-25, 2021; virtual. Accessed May 7, 2021.
5. Piraccini B. Trichoscopy of androgenetic alopecia. American Academy of Dermatology Virtual Meeting Experience 2021; April 23-25, 2021; virtual. Accessed May 7, 2021.