Trichoscopy Simplified

It has been a long while since skin surfaces and skin lesions have been examined by dermoscopy. However examining the hair and the scalp was done again recently and gained attention and slight popularity by the practical tool, namely trichoscopy, which can be called in a simplified way as a dermoscopy of the hair and the scalp. Trichoscopy is a great tool to examine and asses an active scalp disease and hair and other signs can be specific for some scalp and hair diseases. These signs include yellow dots, dystrophic hairs, cadaverized (black dots), white dots and exclamation mark hairs. Trichoscopy magnifies hair shafts at higher resolution to enable detailed examinations with measurements that a naked eye cannot distinguish nor see. Trichoscope is considered recently the newest frontier for the diagnosis of hair and scalp disease. Aim of this paper. The aim of this paper is to simplify and sum up the main trichoscopic readings and findings of hair and scalp disorders that are commonly encountered at clinic dermatology settings.


INTRODUCTION
Any dermatology clinic will be quite busy and in many instances faced with many patients mostly women complaining of hair loss, which can have significant effects on their self-esteem and quality of life. A normal terminal hair is identical in thickness and colour right through its length (Fig. 1). The width of normal hairs is usually more than 55 mm. Trichoscopy of normal scalp illustrates follicular units composing of 2-4 terminal hairs and 1 or 2 vellus hairs (less than 0.03 mm in width).
Trichoscopy can be either performed with a handheld dermoscope or a videodermoscope (with software equipped). Trichoscopy works similar to the skin surface and at right angles to the histological plane; like the histopathology [1]. It should examine hair and scalp in all locations namely frontal, occipital, and temporal areas. The choice of fluid immersion is individual choice. Water, ultrasound gels, aqueous gels, liquid paraffin, alcohol, and oil can be used to enhance clarity and visualization. However air bubbles or paraffin can impede or blurs vision and also gels [2].
Trichoscopy aids in visualizing hair at a working magnifications of 20-fold to 70-fold, and some higher up to 160 [3,4]. Trichoscopy is a quick, easy, priceless, novel, efficient, and a non-invasive device, which can save time and money to achieve a clear-cut diagnosis and enable treatment to start [4]. It assists visualization of the surface and beneath constitutions and colour outlines of scalp and hair [5]. It offers rapid appreciation of scalp and hair disorders, and advances diagnostic accuracy. It predicts the course of the *Address correspondence to this author at the Dermatology OPD, STJTL, Tripoli, Libya; E-mail: ebtisamya@yahoo.com disease and lessens the needless need for biopsies. It can be generally alienated into hair signs, vascular patterns, pigment patterns and interfollicular patterns, all of which can denote specific disease and aid in making the proper diagnosis.
Likewise recently, its function extended to aid in diagnosing some inflammatory scalp conditions like lichen planopilaris (LPP), scalp psoriasis, and discoid lupus erythematosus (DLE).

TRICHOSCOPIC MAIN AND SPECIAL FINDINGS
Starting off with the main clinical appreciations and then the main trichoscopic main findings and recognitions are shown ( Table 1).

Trichoscopic Findings
According to Bhamla et al. [8], the presence of hair with different calibre is classic of FPHL and imitates progressive hair miniaturization due to the disease (about 75% showed anisotrichosis on trichoscopy) (Fig. 2).
Telogen Effluvium (TE): TE is a self-limiting, abrupt generalized hair loss and thinning process, with premature development of catagen and telogen follicles with premature termination of anagen follicles, and almost never causes apparent baldness; however patients panic and complain of handful hair shedding as its severe at earlier stages.

Trichoscopic Findings
Presence of empty hair follicles and decreased hair density, one follicular hair unit dominance (Fig. 3) and perifollicular discolouration (perpilar sign) and upright short hair re-growth [5,9]. TE is a diagnosis of exclusion.
Androgenetic Alopecia (AGA): AGA is the most common form of hair loss both in men and women, and is featured by a progressive loss of hair diameter, length, and pigmentation and over time may become cosmetically undesirable [10].

Trichoscopic Findings
Increased proportion of thin and vellus hairs, anisotrichosis due to miniaturization of the hair follicles (Fig. 5), empty follicle [10], perifollicular discoloration and the presence of a variable number of yellow dots (YD) and decline in one follicular hair unit (Figs. 5, 6).
It has been suggested that a diversity of 20% is diagnostic of FAGA [3, 5, 10].
White dots were seen and are suggested to be related to severe disease stage. They signify empty follicular opening which replaced by fibrosis in advanced phase of the disease (Fig. 7).
There are certain diagnostic criteria for FAGA. Moreover, in FAGA the number of yellow dots, pilosebaceous units with only one hair and with PFP was signifycantly increased in androgenic alopecia.
Previously the exclamation mark was thought to be a sign for recovery and re-growth of the hair. However some studies had contradicted the concept of active disease findings, as a Turkish study by Kibar et al. [15] concluded that white dots and black dots were related to severe disease, while exclamation mark hairs related to mild disease. According to Tosti and Estrada [16], yellow dots, short vellus are sensitive marker of AA and black dots, tapering hairs and broken hairs are most specific marker, and the only markers of AA activity.

Trichoscopic Findings
According to Tosti and Estrada [16], there are numerous, diffuse yellow dots of different size and uniform colours within the follicular orifices of both empty and hair-bearing with a large number of re-growing of tapered terminal hairs in the entire scalp (Fig. 12). Fig. (12). YD in whole scalp; hairy and none hairy areas.
Scalp Psoriasis and Seborrheic Dermatitis: Psoriasis and seborrheic dermatitis are equally chronic erythematosquamous dermatoses that can involve the scalp. It may be hard to distinguish between both clinically when it affects only the scalp [18] and thus it poses a diagnostic challenge, however involvement of frontal hair lines is distinctive for scalp psoriasis.
The zigzag shaped hairs or corkscrew (twisting -coiled) hair looks to be a variant of the comma hair, manifesting in black patients.
It factually means dismal urge and craving to pull out hair repeatedly, with a sense of pleasure, gratification, or relief after the hair is plucked. The pulling behaviour serves as a coping mechanism for anxiety, stress, and other difficult emotions.
It is considered amongst the psycho-cutaneous diseases as it to be associated with psychiatric comorbidity, social, and functional hurt.
The follicular micro-hemorrhage has a diagnostic sign in TTM. It appears as a red dot corresponding follicular ostia that is swollen with the blood clot due to traumatic forceful hair plucking (Fig. 20). Fig. (20). Follicular hemorrhage, black dots, V shape, flame hair and tulip hair [10,11,21,22].
Newly suggested, the flame hairs, v-sign, tulip hairs, and hair powder are added, and Abu emphasize these signs are explicit only for TTM. Flame hairs are semi-transparent, wavy and cone-shaped hair remains, that occurs due to strict mechanical hair pulling and tears up (Figs. 20, 21). Syphilitic Alopecia: Syphilitic alopecia is unusual in patients with secondary syphilis. However it is known to be moth-eaten alopecia. Fig. (21). Tulip hairs [10,11,21,22].

Trichoscopy Findings
Previously the trichoscopic features of syphilitic alopecia have not been looked into. According to Ye et al. [22], there are black dots, focal atrichia, hypopigmentation of hair shaft, empty ostia of hair follicle and yellow dots (Fig. 22).   Fig. (22). Black and yellow dots [16].

CICATRICIAL ALOPECIAS
Recently it has been discovered that the scarring incurred are due to irreversible insult of the stem-cell-rich bulge area of the hair, which is required for the cyclic regeneration of the lower follicle [16]. Thus in any trichoscopy we can expect no hair follicle orifice and a fibrous white band.
Lichen Planopilaris (LPP): LPP clinically manifest as purplish plaques affecting the central scalp, and then ending up at later stages with atrophy and permanent alopecia of the scalp [23].
Frontal Fibrosing Alopecia (FFA): FFA is a clinical variant of lichen planopilaris, and is distinguished by the recession of the frontotemporal hairline (FTHL) [25].

Trichoscopic Findings
Trichoscopic findings are loss of follicular opening, follicular hyperkeratosis, follicular plugs and erythema. And according to Toledo et al. [25] the presence of perifollicular erythema will be a direct marker of FFA activity (Fig. 25).

Discoid Lupus Erythematosus (DLE)
: DLE clinically appears as erythematous scaly follicular plaques in the early stages, which then get thickened with adherent scales and follicular plugging [23]. In late stage, lesions become depressed (atrophy), depigmented, with telengiectasia, and the follicular openings is completely lost. DLE may show hair re-growth if promptly treated and thus early treatment is important [16].
According to Tosti and Estrada [16] scalp atrophy is appreciated by a diffuse white colour of the scalp. Arborizing and tortuous vessels are seen inside DLE plaques. Red to pinkish-red, round and polycyclic dots of uniform size are often distributed around follicular openings and may be a peculiar finding as well.

Folliculitis Decalvans (FD) and Tufted Folliculitis (TF):
Folliculitis decalvans (baldheadedness with scarring) is a variety of alopecia that associated with scarring. It is distinguished by redness, swelling and pustules oozing pus around the hair follicle which leads to inflammation of the hair follicle (folliculitis) with damage of the hair follicle and thus permanent hair loss with scaring. It is also called tufted folliculitis (TF) [26].

Dissecting Cellulitis (DC):
Is an uncommon condition that affects the scalp vertex and posterior neck, commonly seen in black males (skin type 5&6) aged 20-40 years, and called doll hair (Fig. 30).
It starts clinically as simple folliculitis or perifolliculitis then rapidly erupts as multiple painful nodules with purulent discharge that coalesce to form interconnecting abscesses and sinuses.
Pseudopelade Brocq: Pseudopelade of Brocq is an unusual form of enduring alopecia of the scalp and mostly affects middle aged and older women. The cause of which is unknown. Its diagnosis by exclusion of LPP and DLE, and described as 'foot print in snow'.

Trichoscopy Features
According to Rudnicka et al. [27], the trichoscopy features of classic pseudopelade of Brocq are nonspecific. It appears as white areas with no follicular openings. Also some solitary dystrophic hairs can be seen at the periphery of the lesion. Fig. (25). Perifollicular scales, follicular hyperkeratosis, follicular plugs and erythema [3].

Trichoscopy Simplified
The Open Dermatology Journal, 2015, Volume 9 19 Fig. (26). Numerous yellow Follicular keratotic plugging [25]. Fig. (27). Thick arborizing blood vessels, and red follicular dots interspersed with scar areas [1]. Fig. (28). Tufted hair [13]. Fig. (29). Polytrichia and redness [17]. In closing, diffuse hair loss of different intensity is a frequent complaint, in particular among women. Trichoscopy is a very useful handy and non-invasive tool in the armamentarium of dermatologist for the clinical evaluation and diagnosis of hair and scalp disorders. It enhances diagnostic potential, and revealed new novel features to advance our understanding. Nonetheless, the diagnosis cannot be made without a clinical case approach, available data, and histology reading in some cases. All are complement to each other.