Indian Journal of Paediatric Dermatology

RESIDENTS CORNER
Year
: 2019  |  Volume : 20  |  Issue : 2  |  Page : 183--186

Relevance of circular hair by trichoscopy in pediatric age group


Tarang Goyal, Sakshi Kohli 
 Department of Dermatology, Venereology and Leprosy, Muzaffarnagar Medical College and Hospital, Muzaffarnagar, Uttar Pradesh, India

Correspondence Address:
Dr. Tarang Goyal
Department of Dermatology, Muzaffarnagar Medical College and Hospital, Muzaffarnagar, Uttar Pradesh,
India




How to cite this article:
Goyal T, Kohli S. Relevance of circular hair by trichoscopy in pediatric age group.Indian J Paediatr Dermatol 2019;20:183-186


How to cite this URL:
Goyal T, Kohli S. Relevance of circular hair by trichoscopy in pediatric age group. Indian J Paediatr Dermatol [serial online] 2019 [cited 2019 Nov 13 ];20:183-186
Available from: http://www.ijpd.in/text.asp?2019/20/2/183/255199


Full Text



 Introduction



Trichoscopy is the dermoscopic evaluation of the hair and scalp. Structures which may be visualized by trichoscopy include hair shafts, hair follicle openings, perifollicular epidermis, and cutaneous microvasculature. Trichoscopy allows easy detection of various hair shaft abnormalities due to curling and twisting of the hair shaft giving rise to a circular shape. However, as of now, there is a paucity of literature and great degree of confusion with regard to terminology in the use of different types of circular hair seen in a variety of hair and scalp disorders, particularly in pediatric age group. In this article, we aim to provide a comprehensive review regarding the relevance of circular hair in the pediatric age group.

 What Are Circle Hair and in Which Sites They Are Commonly Seen?



Circle hairs (CHs) were first described clinically by Adatto[1] in 1963 and by Argueta and Tschen[2] by the use of dermoscope in 2014. These are asymptomatic hair located under a thin skin layer corresponding to stratum corneum, with perfect circular or spiral arrangement, and are seen commonly seen on posterior arms, shoulder, back, and buttocks [Figure 1]. These tend to grow in elderly, hairy and obese males, predominantly on the torso and thighs.[3] These are not associated with follicular abnormalities or inflammation.{Figure 1}

 What is the Pathogenesis of Circle Hairs?



The pathogenesis of CHs is obscure. Some authors have stated CH to have small follicular diameter which makes it difficult to penetrate the stratum corneum, for which reason they grow in a circular tract and in a subcorneal location.[4] Others state that these are a genetically predetermined disorder and as the follicular ostia are continuously open, there is no need for hair to penetrate the ostium.[5] There has been a possibility that these hairs correspond to vestigial of the mammal undercoat as quoted by some authors.[5]

 What Are the Characteristic, Trichosopic, and Histopathological Findings of Circle Hairs?



After pulling from the skin, the CHs show typical “Question mark” appearance which when released, returns back to its original format with partially or fully recoiled shape.[4],[5] On histopathological examination, these show “River bed” dilated follicular infundibula with entrapped hair shafts. They show dystrophic bulb in anagen phase, absence of inner root sheath, and narrowing of distal hair shaft forming circular track. The hair follicle density remains normal; and intermediate, miniaturized, anagen and catagen hair follicles are seen.[6]

 Have Circle Hairs Shown to Be Associated With Any Disorder of Hair Shaft?



Yes, CHs have been associated with pili multigemini in a young female.[7]

 What is the Differential Diagnosis of Circle Hairs?



CHs have to be differentiated from rolled hairs (RHs), the closest differential diagnosis.[4]

 What Are Rolled Hair and Why Are They Important?



RHs are irregularly coiled hair, which may be found on the surface or beneath the stratum corneum and are associated with follicular hyperkeratosis and keratin plugging. These are not perfectly circular as opposed to CHs and can be the result of mechanical trauma associated with frequent and repeated friction[8] [Figure 2].{Figure 2}

 What is the Significance of Rolled Hairs With Respect to Pediatric Dermatology?



The RHs are very significant finding as they are found to be associated with a number of hair disorders such as scurvy, atopic dermatitis, keratosis pilaris, ichthyosis, palmoplantar keratodermas, neurodermatitis, and xerosis.[3],[4],[5] Of the drug-induced causes, these have been found to be associated with corticosteroid therapy and cyclosporine therapy.[9],[10]

 What are the Sites Where Rolled Hairs are Commonly Found?



RH most commonly affects the extensor extremities but also the back, shoulders, and buttocks.[6]

 What is the Pathogenesis of Rolled Hairs?



The RHs, unlike CHs, are not perfectly circular, are irregularly coiled within a hyperkeratotic papule, and are associated with signs of inflammation. The distorted form of this hair has been thought to be because it is very thin and is unable to pass through the corneal layer.

 What is the Appearance of Rolled Hairs on Trichoscopy?



These appear as irregularly twisted hair in a hyperkeratotic papule.[11] When the keratin follicular plug is removed, it reveals the RH that is inside the follicle.[12]

 What is the Histopathology of Rolled Hairs?



Histologic findings are mostly follicular hyperkeratosis, and it is believed that the RH is a consequence of the incapacity of the hair follicle to emerge through the skin surface.[13]

 Why is it Important to Differentiate between Circle Hairs and Rolled Hairs?



Both CHs and RHs are benign. However, RHs can be related to other skin disorders that need additional treatment and can be a valuable diagnostic marker for the presence of these disorders.

 What are Pigtail Hairs?



The term “Pigtail hair” refers to circular or oval short hair regularly twisted hair with tapered and coiled distal end, similar to a pig's tail [Figure 3].{Figure 3}

 What is the Characteristic of Pigtail Hairs?



Pigtail hairs are new thin, re-growing hairs which are uniform in thickness, color, and shape. They demonstrate the regrowth of terminal hairs from hair follicles that are not fully intact.[14]

 In Which Disorders Do We Find the Pigtail Hairs?



Resolving alopecia areata, lichen planopilaris, and chemotherapy-induced alopecia has been shown to have pigtail hair. Isolated pigtail hairs have been reported to be seen in cicatricial alopecia also.[14]

 What is the Closest Differential Diagnosis of Pigtail Hairs?



The closest differential diagnosis of pigtail hair is coiled hair.

 What are Coiled Hairs?



Coiled hairs are broken hairs that curl back. Owing to pulling force the hair shaft fractures and the lower part or remaining attached shaft coils and contracts resulting in coiling, hence the appearance. These are also known as “Hook hair” or “Question mark hair.”

 In Which Disorders Do We See the Coiled Hairs?



We see coiled hairs in traction alopecia, trichotillomania, and even normally in individuals during the hair-spa procedures due to pulling.

 What is the Difference between Pigtail Hairs and Coiled Hairs?



The pigtail hairs are regularly twisted and tapered (pinpoint) distal end. However, the coiled hairs are fractured hair resulting from a pulling force on hair shaft causing hair fracture, leading to partial coiling of distal part of the hair. These frequently show features of trichoptilosis (split end).

 What are Comma Hairs?



Comma hairs are highly characteristic trichoscopic features of tinea capitis. They were first demonstrated by Slowinska et al. in 2008, in a patient with tinea capitis due to Microsporum canis. The comma hair may represent an intermediate stage in the evolution of tinea capitis before the formation of dystrophic hairs, characterized by a sharp slanting end, homogeneous thickness, and pigmentation of the hair shaft[15] [Figure 4]. Comma hairs have been demonstrated in both ectothrix and endothrix type of fungal invasion.[16] Comma hairs have been detected in tinea capitis due to M. canis, Microsporum langeronii, Tricophyton tonsurans, Trichophyton violaceum, and Trichophyton soudanense.{Figure 4}

 What are Corkscrew Hairs?



Corkscrew hairs are another characteristic, trichoscopic finding of tinea capitis which were first described by Hughes et al. in 2011 in patients with infection and they show more exaggerated coiled appearance of the hair shaft with multiple twists[17] [Figure 4]. Historically, corkscrew hairs were defined as normal terminal body hairs that curl spontaneously in patients with hypovitaminosis C (scurvy). These two types of corkscrew hairs share the same name, but their clinical appearance and etiopathogenesis are different.[14]

Financial support and sponsorship

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Conflicts of interest

There are no conflicts of interest.

References

1Adatto R. Spiral hair (coiled hair). Dermatologica 1963;127:145-7.
2Argueta EE, Tschen JA. Hairs with an irregular shape. Cutis 2014;94:E4-5.
3Levit F, Scott MJ Jr. Circle hairs. J Am Acad Dermatol 1983;8:423-5.
4Smith JB, Hogan DJ. Circle hairs are not rolled hairs. J Am Acad Dermatol 1996;35:634-5.
5Contreras-Ruiz J, Duran-McKinster C, Tamayo-Sanchez L, Orozco-Covarrubias L, Ruiz-Maldonado R. Circle hairs: A clinical curiosity. J Eur Acad Dermatol Venereol 2000;14:495-7.
6Lacarrubba F, Misciali C, Gibilisco R, Micali G. Circle hairs: Clinical, trichoscopic and histopathologic findings. Int J Trichology 2013;5:211-3.
7Nair PA, Kota RS, Gandhi S, Singhal RR. A rare association of pili multigemini and rolled hairs in a young female. Int J Trichology 2016;8:29-31.
8Esteves AL, Serafini NB, Lemes LR, Melo DF. Circular hairs: Nomenclature and meanings. An Bras Dermatol 2017;92:874-6.
9Fergusson AG, Derblay PR. Rolled hairs. A possible complication of corticosteroid therapy. Arch Dermatol 1963;87:311-4.
10Seçkin D, Güleç TO, Haberal M. Higher incidence of rolled hairs in renal transplant recipients: A possible complication of corticosteroid and cyclosporine therapy. Acta Derm Venereol 1998;78:384.
11Kanerva L, Niemi KM, Lassus A, Rantanen T. Scanning electron microscopic visualization of rolled hair (Poils en spirale). Acta Derm Venereol 1983;63:61-4.
12Ortonne JP, Juhlin L, el Baze P, Pautrat G. Familial rolled and spiral hairs with palmoplantar keratoderma. Acta Derm Venereol 1985;65:250-4.
13Panchaprateep R, Tanus A, Tosti A. Clinical, dermoscopic, and histopathologic features of body hair disorders. J Am Acad Dermatol 2015;72:890-900.
14Rudnicka L, Olszewska M, Rakowska A, editors. Atlas of Trichoscopy: Dermoscopy in Hair and Scalp Disease. 2nd ed. London: Springer-Verlag; 2012.
15Slowinska M, Rudnicka L, Schwartz RA, Kowalska-Oledzka E, Rakowska A, Sicinska J, et al. Comma hairs: A dermatoscopic marker for tinea capitis: A rapid diagnostic method. J Am Acad Dermatol 2008;59:S77-9.
16Sandoval AB, Ortiz JA, Rodríguez JM, Vargas AG, Quintero DG. Dermoscopic pattern in tinea capitis. Rev Iberoam Micol 2010;27:151-2.
17Hughes R, Chiaverini C, Bahadoran P, Lacour JP. Corkscrew hair: A new dermoscopic sign for diagnosis of tinea capitis in black children. Arch Dermatol 2011;147:355-6.