Trichoscopic structures and patterns

5.00

(1 vote)

 Editor: Anna Waskiel Burnat

 Author(s): Anna Waskiel Burnat     ·  Lidia Rudnicka

→ cite chapter  → become an author 

Annotations
Description	This chapter describes tricoscopy structuresThis glossary term has not yet been described. and patternsThis glossary term has not yet been described. as seen by dermoscopyThe examination of [skin lesions] with a 'dermatoscope'. This traditionally consists of a magnifier (typically x10), a non-polarised light source, a transparent plate and a liquid medium between the instrument and the skin, and allows inspection of skin lesions unobstructed by skin surface reflections. Modern dermatoscopes dispense with the use of liquid medium and instead use polarised light to cancel out skin surface reflections.
Author(s)	Anna Waskiel Burnat · Lidia Rudnicka
Responsible author	Anna Waskiel Burnat → send e-mail
Status	released
Status update	December 4, 2018
Status by	Ralph P. Braun

This chapter describes tricoscopy structures and patterns as seen by dermoscopy

It has the following subchapters:

Hair shafts	Anna Waskiel Burnat, Lidia Rudnicka
Hair follicle openings	Anna Waskiel Burnat, Lidia Rudnicka
Perifollicular and interfollicular skin surface	Anna Waskiel Burnat, Lidia Rudnicka
Blood vessels (scalp)	Anna Waskiel Burnat, Lidia Rudnicka
Normal trichoscopic findings	Anna Waskiel Burnat, Lidia Rudnicka

Trichoscopy, Structures, Patterns Trichoscopic structures and patterns – cite! Trichoscopic structures and patterns (message) Trichoscopic structures and patterns – participate!

User=

Trichoscopic structures and PatternsThis glossary term has not yet been described.

Trichoscopic features can be divided into 4 main groups: hair shafts, hair follicle openingsThis glossary term has not yet been described., perifollicular epidermis and blood vesselsare the part of the circulatory system, and microcirculation, that transports blood throughout the human bodyThis glossary term has not yet been described. [1].

Hair shafts

• A normal terminal hair are more than 55 µm wide and are uniform in thickness and color [1].
• The trichoscopic classificationis a general process related to categorization, the process in which ideas and objects are recognized, differentiated, and understood. of hair shaftThis glossary term has not yet been described. abnormalities is proposed by Rudnicka et al. [2].

Fractured hairsThis glossary term has not yet been described.

Trichoptilosis	Trichoschisis or trichoclasis	Broken hairs	Golf tee hairs
Longitudinal splitting of the distal end of hair shaft	A clean transverse fracture across the hair shaft	Irregular transverse fracture across the hair shaft	A hair with a concave distal end
Unspecific manifestation of a defect in hair shaft structure	Trichothiodystrophy, secondary to conditions that weaken the hair shaft	TrichotillomaniaThis glossary term has not yet been described., traction alopecia, alopecia areataThis glossary term has not yet been described., tinea capitisThis glossary term has not yet been described.	Specific for Netherton syndrome

Narrowings

Monilethrix	Monilethrix-like congenital Hypotrichosis	Monilethrix-like hairs (Pohl-Pinkus constriction)	Pseudomonilethrix	Exclamation mark hairs	Tapered hairs
Hair with regularly distributed nodes and narrowings The nodes correspond to normal hairThis glossary term has not yet been described. shaft thickness; the internodes are the narrowings	As in monilethrix, but the spaces between narrowings are extremely short	Hair with irregularly distributed narrowings (Pohl-Pinkus constrictions)	Differs from monilethrix—nodes appear thicker than the normal hair shaft and internodes have the thickness of the normal hair	Hairs with a thin, usually hypopigmented proximal end and thicker, pigmented distal end	Long exclamation mark hairs, the distal end is outside the field of view of a dermoscope
Specific for monilethrix	Specific for monilethrix-like congenital hypotrichosis	Alopecia areataThis glossary term has not yet been described., chemotherapyinduced alopecia, bleeding, malnutrition Artificial: monilethrix-like effect from hair styling gel or immersionThis glossary term has not yet been described. fluid	Controversial	Alopecia areata, chemotherapyinduced alopecia, intoxication, trichotillomaniaThis glossary term has not yet been described.	Alopecia areata, cicatricial alopeciaThis glossary term has not yet been described., trichotillomania, bleeding, malnutrition, chronic intoxication

Node-like appearance

Trichonodosis (hair knotting)	Trichorrhexis nodosa	Trichorrhexis invaginata (bamboo hairs)	Hair casts (peripilar keratin casts)
A single or double knot in the hair shaft	A hair shaft with a restricted area where the shaft splits longitudinally into numerous small fibers The outer fibers bulge out, causing a segmental increase in hair diameter	The hair shaft telescopes into itself The proximal part of the abnormality is concave and the distal end is convex (bulging), producing an impression of nodular swelling along the hair shaft	Firm, white, tubular masses that encircle the hair shafts
No clinical significance	Multiple acquired and inherited diseases, commonly due to mechanical or chemical traumaThis glossary term has not yet been described.	Specific for Netherton syndrome	A nonspecific finding, commonly associated with scaling or epidermal detachment Traction alopecia

Curls and twists

Pigtail hairs	Coiled hairs	Comma hairs	Corkscrew hairs	Zigzag hairs	Pili torti	Wooly hairs
Short, regularly coiled hairs with tapered ends	Irregularly coiled hairs with a jagged end When not fully coiled, they may have a hook-like appearance	Short, comma-like (C-shaped) hairs, homogeneous in thickness and pigmentation	Hairs with multiple twists and coils, forming corkscrew-like structures	Hairs, bent at sharp angles, form zigzag structures	Hairs that are flattened and twisted on their own axis at irregular intervals, usually through an angle of 180°	Hair shafts with waves at very short intervals, giving a crawling snake appearance
Alopecia areata	Trichotillomania	Tinea capitisThis glossary term has not yet been described.	Tinea capitis	Tinea capitis, alopecia areata	Associated with multiple inherited and acquired hair diseases	Inherited syndromes

Bands

Continuous Medulla	Interrupted Medulla	Pili annulati	Interrupted (Morse Code-like) hairs
Longitudinal white band along the midpart of the hair shaft that covers less than 50% of the hair shaft thickness	Interrupted longitudinal white band along the midpart of the hair shaft The band covers less than 50% of the hair shaft thickness	Hair shafts with transverse light, blurry, whitish bands covering (nearly) the width of a hair	Hairs with multiple thin white bands across the hair shaft
Normal	Normal	Hair shafts with transverse light, blurry, whitish bands covering (nearly) the width of a hair	Tinea capitis

Short hairs

Upright regrowing	Vellus hairs	Dark lines	Tulip hairs	Block hairs	i-Hairs	Broom hairs	Broom fibers	Flame hairs
New, healthy, regrowing hairs that have a tapered end and a straight-up position	Short, thin, hypopigmentedThis glossary term has not yet been described., delicate, nonmedullated hairs, usually somewhat wavy in shape	Thin, short, intensely pigmented hairs, appearing tapered at both sides	Short hairs with a tulip leaf-like hyperpigmentation at the distal end	Very short hairs with a transverse horizontal distal end	i-Hairs are block hairs with an accented dark distal end	Few or more linear, short hairs emerging from one follicular opening	Few or more linear, short, dark fibers (significantly thinner than terminal hairs) emerging from one follicular opening	Hair residues, semitransparent, wavy, and cone-shaped, resembling a fire flame
Normal; If abundant, may reflect a regrowth phase of telogen effluviumThis glossary term has not yet been described.	Normal; If abundant, may reflect androgenetic alopeciaThis glossary term has not yet been described.	Noncicatricial alopecia	Trichotillomania	Noncicatricial alopecia associated with shaft hair fragility	Noncicatricial alopecia associated with high shaft hair fragility (eg, tinea capitis)	Observed in diverse entities, both cicatricial and noncicatricial	Observed in diverse entities, both cicatricial and noncicatricial	Trichotillomania

Adapted from Rudnicka et al. [2]

Hair follicle openings

"DotsDots are small, round structures of less than 0.1 mm in diameter that have a red color when corresponding to blood vessels; however, when due to melanin, their color ranges from black, brown, to blue-gray depending on the depth and concentration of the melanin in the skin (Tyndall effect)." correspond to hair follicle openings observed in trichoscopic examination [1].

Black dotsDots are small, round structures of less than 0.1 mm in diameter that have a red color when corresponding to blood vessels; however, when due to melanin, their color ranges from black, brown, to blue-gray depending on the depth and concentration of the melanin in the skin (Tyndall effect).

Black dots, also known as “cadaverized hairs”, represent pigmented hairs broken or destroyed at scalpThis glossary term has not yet been described. level [1]. They are commonly observed in alopecia areata [3], dissecting cellulitis [4, 5], trichotillomania [6] and tinea capitis [4]. Black dots may be also detected in chemotherapy-induced alopecia [4], lichen planopilarisThis glossary term has not yet been described. [7], discoid lupus erythematosusis a chronic skin condition of sores with inflammation and scarring favouring the face, ears, and scalp and at times on other body areas. These lesions develop as a red, inflamed patch with a scaling and crusty appearance. The centre areas may appear lighter in colour with a rim darker than the normal skin. [7], traction alopecia [7], traumatic alopecia [8], androgenetic alopecia [8, 9] and following a laser depilation or trichogram [1].

Yellow dots

Yellow dots correspond to follicular infundibula filled with sebum and/or keratotic material [10]. They present as yellow, or whitish, round or polycyclic dots, varied in size and uniformed in colorColor (American English) or colour (Commonwealth English) is the characteristic of human visual perception described through color categories, with names such as red, yellow, purple, or blue., devoid of hairs or containing miniaturized, cadaverized or dystrophic hairs [10-12].
In alopecia areata, yellow dots are characterized by an abundant amount and regular distribution and predominate in long-lasting, inactive disease [3, 13].
The predominance of yellow dots (they are predominantly sebaceous) in the frontal area compared to the occipital area is characteristic for androgenetic alopecia [14]. They correspond to empty follicular openings of follicles in kenogen phase.
In discoid lupus erythematosus, large, dark yellow dots that correspond to wide infundibula filled with keratotic material are observed [1, 5].
Yellow dots, appearing as large "3D" soap bubbles imposed over dark dystrophic hairs are specific for dissecting cellulitis [1, 5].
Sparse yellow dots may also be detected in chronic telogen effluvium [8, 9], traumatic alopecia [8] traction alopecia [7], congenital hypotrichoses and kerion celsi [15].

Red dots

Red dots correspond to widened infundibula plugged by keratin and surrounded by dilated vesselsThis glossary term has not yet been described. and extravasated erythrocytes [16]. They are characteristic trichoscopic finding for active discoid lupus erythematosus and believed to be a positive prognostic factor [5].

White dots

There are two types of white dots.
The classic, big, irregular white dots correspond to areas of perifollicular fibrosis and are observed most commonly in lichen planopilaris [1].
The small, regular pinpoint white dots represent hair follicle openings and eccrine sweat gland openings and are observed in sun exposed areas and in dark skin phototypes regardless of hair loss [1].

Perifollicular and interfollicular skin surface

In trichoscopyThis glossary term has not yet been described., following perifollicular and interfollicular skin surface abnormalities may be observed: scaling, discoloration, discharge and surface structure.

Scaling

Epidermal scaling can be divided into perifollicular and diffuse [13].

Mild diffuse scaling may be observed in healthy persons with dry skinThis glossary term has not yet been described.. White moderate to severe diffuse scaling is detected in psoriasisThis glossary term has not yet been described., discoid lupus erythematosus and contact dermatitisalso known as eczema is a group of diseases that results in inflammation of the skin.. Yellowish moderate to severe diffuse scaling is presented in seborrheic dermatitisThis glossary term has not yet been described., discoid lupus erythematosus and ichthyosis [13].

White perifillicular, tubular scaling is characteristic for lichen planopilaris. In folliculitis decalvans, yellowish, tubular with collar formation is observed [13]. It needs to be emphasized, that diffuse “scaling” with formation of white perifollicular clusters may be present in monoclonal gammopathy [13].

Discoloration

Brown areas in trichoscopy may occur in three different patterns.
Honeycomb pattern comprises a homogenous, mosaic or contiguous brown rings. It may be observed in chronically sun-exposed areas of thinning or complete hair loss and the scalp of dark-skinned patients [17]. Perifollicular brown coloration results from perifollicular lymphocytic infiltration [14] and is commonly detected in androgenetic alopecia, telogen effluvium. It may be presented in up to 10% of hair follicle openings in healthy persons [14, 18]. Scattered brown discoloration is typical feature of discoid lupus erythematosus [5].

Pink, “strawberry ice cream” areas are characteristic trichoscopic findings of cicatricial alopecia and correspond to early fibrosis [5].

Red areas may be observed in case of inflammationThis glossary term has not yet been described., extravasation, epidermal detachment and vascular abnormalities [13].

White areas are common feature of cicatricial alopecia and correspond to late fibrosing process [5]. They may be also observed in epidermal detachment and edema [13].

Yellow areas are detected in dissecting cellulitis, follicular pustules, dissecting cellulitis and bacterial infections [13].

Discharge

Yellow or yellow-red discharge is detected in folliculitis decalvans, bacterial infections, dissecting cellulitis or tinea capitis [13].

Surface structure

Starburst patternThis pattern consists of peripheral globules, pseudopods or streaks (or a combination of them), located around the entire perimeter of the lesion hyperplasia results from fibrosis and is characteristic trichoscopic findings of folliculitis decalvans [5].

Blood vesselsare the part of the circulatory system, and microcirculation, that transports blood throughout the human bodyThis glossary term has not yet been described.

Comma vesselslinear curved short vessels dermal nevi	Dotted vesselstiny pinpoint vessels	Hairpin vessels	Elongated hairpin vessels	Straight linear vesselsLinear mildly curved vessels considered irregular when different sizes shapes and curves with a haphazard or random distribution are presented and considered regular when short and fine (thin) linear vessels prevail various diagnoses	Thin arborizing vesselsanalytic term is branched vessels; Bright red sharply in focus large or thick diameter vessels dividing into smaller vessels; BCC	Thick arborizing vessels	Capillary blood extravasations	Concentric perifollicular vessels	Milky red globulesThis glossary term has not yet been described.	Linear helical vesselscorkscrew twisted looped vessels with bends twisted along a central axis melanoma metastasis	Lace-like vessels	Glomerular vessels	Serpentine vesselslinear irregular vessels with multiple bends. Seen with flat BCC and melanoma	Thick root-like vessels	Vessel nets
C-shaped or slightly curved vesselscomma vessels - linear curved short vessels - dermal nevi monomorphous vessels: one type of vessel dominates	Tiny, red dots densely aligned next to each other	Small, linear looped vesselsmetaphoric term: hairpin vessels <br /> two parallel linear vessels forming a half looped or hairpin like structure <br /> seen in seborrheic keratosis viral warts	Elongated, linear looped vessels	Straight linear vessels	Thinner than the average terminal hair arborizing vessels	Thicker than the average terminal hair arborizing vessels	Round or oval, sharply demarcated, intensely red areas	VesselsThis glossary term has not yet been described. (loops or linear) arranged concentrically around a follicular unit	Globules or larger areas of a fuzzy or unfocused milky red color	Linear vesselsLinear mildly curved vessels considered irregular when different sizes shapes and curves with a haphazard or random distribution are presented and considered regular when short and fine (thin) linear vessels prevail various diagnoses twisted along a central axis	CombinationThis glossary term has not yet been described. of serpentine and looped vessels	Coiled or twisted vessels	Bending, scarcely branching vessels	Thick, irregularly banded, linear vessels	Interfollicular networkThis glossary term has not yet been described. of blood vessels
InflammatoryThis glossary term has not yet been described. scalp diseases (seborrheic dermatitis, psoriasis), healthy persons	Healthy persons in the frontal area, eczema	Healthy persons in the frontal area	Cicatricial alopeciaThis glossary term has not yet been described. (lichen planopilaris, folliculitis decalvans), T-cell lymphomaThis glossary term has not yet been described.	Pemphigus vulgaris	Healthy persons (the occipital and temporal area), seborrheic dermatitis	Discoid lupus erythematosusis a chronic skin condition of sores with inflammation and scarring favouring the face, ears, and scalp and at times on other body areas. These lesions develop as a red, inflamed patch with a scaling and crusty appearance. The centre areas may appear lighter in colour with a rim darker than the normal skin., basal cell carcinomais the most common skin cancer, and one of the most common cancers in the United States.[1] While BCC has a very low metastatic risk, this tumor can cause significant disfigurement by invading surrounding tissues	Active psoriasis	Cicatricial alopecia (lichen planopilaris, folliculitis decalvans)	T-cell lymphoma, psoriasis	PsoriasisThis glossary term has not yet been described., pemphigus, T-cell lymphoma	Psoriasis	Psoriasis	Discoid lupus erythematosus	Discoid lupus erythematosus, congenital capillary malformations	Healthy persons, after topical corticosteroids

1. Rudnicka, L., et al., TrichoscopyThis glossary term has not yet been described. update 2011. J Dermatol Case Rep, 2011. 5(4): p. 82-8.
2. Rudnicka, L., et al., Hair shafts in trichoscopy: cluesEvidence, in an investigation for diagnosisis the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines with variations in the use of logic, analytics, and experience to determine "cause and effect". In systems engineering and computer science, it is typically used to determine the causes of symptoms, mitigations, and solutions of hair and scalp diseases. Dermatol Clin, 2013. 31(4): p. 695-708, x.
3. Inui, S., et al., Clinical significance of dermoscopy in alopecia areata: analysis of 300 cases. Int J Dermatol, 2008. 47(7): p. 688-93.
4. Kowalska-Oledzka, E., et al., 'Black dots' seen under trichoscopy are not specific for alopecia areata. Clin Exp Dermatol, 2012. 37(6): p. 615-9.
5. Rakowska, A., et al., Trichoscopy of cicatricial alopecia. J Drugs Dermatol, 2012. 11(6): p. 753-8.
6. Rakowska, A., et al., New trichoscopy findings in trichotillomania: flame hairs, V-sign, hook hairs, hair powder, tulip hairs. Acta Derm Venereol, 2014. 94(3): p. 303-6.
7. Shim, W.H., et al., Dermoscopic approach to a small round to oval hairless patch on the scalp. Ann Dermatol, 2014. 26(2): p. 214-20.
8. Park, J., et al., Trichoscopic Findings of Hair Loss in Koreans. Ann Dermatol, 2015. 27(5): p. 539-50.
9. Karadag Kose, O. and A.T. Gulec, Clinical evaluation of alopecias using a handheld dermatoscopeThis traditionally consists of a magnifier (typically x10), a non-polarised light source, a transparent plate and a liquid medium between the instrument and the skin, and allows inspection of skin lesions unobstructed by skin surface reflections. Modern dermatoscopes dispense with the use of liquid medium and instead use polarised light to cancel out skin surface reflections.. J Am Acad Dermatol, 2012. 67(2): p. 206-14.
10. Ross, E.K., C. Vincenzi, and A. Tosti, Videodermoscopy in the evaluation of hair and scalp disorders. J Am Acad Dermatol, 2006. 55(5): p. 799-806.
11. Chiramel, M.J., et al., Relevance of trichoscopy in the differential diagnosis of alopecia: A cross-sectional study from North India. Indian J Dermatol Venereol Leprol, 2016. 82(6): p. 651-658.
12. Kibar, M., et al., Trichoscopic findings in alopecia areata and their relation to disease activity, severity and clinical subtype in Turkish patients. Australas J Dermatol, 2015. 56(1): p. e1-6.
13. Rudnicka, L., M. Olszewska, and A. Rakowska, Atlas of trichoscopy: dermoscopy in hair and scalp disease. 2012, London: Springer.
14. Rakowska, A., et al., DermoscopyThe examination of [skin lesions] with a 'dermatoscope'. This traditionally consists of a magnifier (typically x10), a non-polarised light source, a transparent plate and a liquid medium between the instrument and the skin, and allows inspection of skin lesions unobstructed by skin surface reflections. Modern dermatoscopes dispense with the use of liquid medium and instead use polarised light to cancel out skin surface reflections. in female androgenic alopecia: method standardization and diagnostic criteriameasure of how well one variable or set of variables predicts an outcome. Int J Trichology, 2009. 1(2): p. 123-30.
15. Inui, S., Trichoscopy for common hair loss diseases: algorithmic method for diagnosis. J Dermatol, 2011. 38(1): p. 71-5.
16. Tosti, A., et al., Follicular red dots: a novel dermoscopic pattern observed in scalp discoid lupus erythematosus. Arch Dermatol, 2009. 145(12): p. 1406-9.
17. Waskiel, A., et al., Trichoscopy of alopecia areata: An update. J Dermatol, 2018.
18. Rakowska, A., Trichoscopy (hair and scalp videodermoscopy) in the healthy female. Method standardization and norms for measurable parameters. J Dermatol Case Rep, 2009. 3(1): p. 14-9.