Journal List > Ann Dermatol > v.29(2) > 1095860

Ann Dermatol. 2017 Apr;29(2):254-256. English.
Published online March 24, 2017.
Copyright © 2017 The Korean Dermatological Association and The Korean Society for Investigative Dermatology
Pili Annulati with Multiple Fragile Hairs
Chan Hee Nam, Minkee Park, Mi Soo Choi, Seung Phil Hong, Myung Hwa Kim and Byung Cheol Park
Department of Dermatology, College of Medicine, Dankook University, Cheonan, Korea.

Corresponding author: Byung Cheol Park, Department of Dermatology, College of Medicine, Dankook University, 119 Dandae-ro, Dongnam-gu, Cheonan 31116, Korea. Tel: 82-41-550-6485, Fax: 82-41-552-7541, Email:
Received February 13, 2016; Revised May 03, 2016; Accepted May 04, 2016.

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Dear Editor:

A 25-year-old man visited Department of Dermatology, Dankook University Hospital with a complaint of whitish dots on his scalp hair that was coarse and broken easily. He noticed the changes for the first time about 6 years ago. He had used a hairdryer almost every day since he graduated high school. No family history except his father had androgenic alopecia. A physical examination revealed that the hair shafts were black mixed with alternating light brown color and multiple small white-gray spots were evident (Fig. 1A, B). On dermoscopic examination, the hair shafts had alternating light and dark bands with multiple white nodes (Fig. 1C). Light microscopy revealed an air-filled dark space or cavity, which appeared to be bright bands or white-gray beads on the hair shaft with the unaided eye (Fig. 1D). A scanning electron microscope showed loss of the cuticle, mild indentation and longitudinal fissuring on the hair shaft that revealed the microfibers of the cortex (Fig. 2A, B). In addition, white nodular swelling was evident that resembled the ends of two brushes aligned in opposition, and the end of the fractured hairs was a paint-brush appearance (Fig. 2C, D).

Fig. 1
(A) Regular alternating bright bands on hair shafts. (B) Multiple white-gray spots appearing like grains of sand exist on the hair shaft. (C) Alternating dark and bright bands with intermittent whit spots on the hair shaft appeared on the dermoscopic examination. (D) The air-filled dark spaces occupied 40%~80% of the hair shaft on inverted microscopy.
Click for larger imageDownload as PowerPoint slide

Fig. 2
(A) Loss of cuticle and mild indentation on the surface of mildly damaged hair. (B) Longitudinal cracks are visible in the hair shaft, which exposed the microfibers of the hair cortex. (C) Swollen node resembles two broomsticks pushed into each other and formed a so-called thrust paint brush. (D) Mechanical trauma on the swollen node fractured the hair ends, as shown by the frayed macrofibers.
Click for larger imageDownload as PowerPoint slide

Pili annulati (PA) has not been classically associated with increased hair fragility, as and tensile strength of hair in cases of PA is normal1. It has been suggested that intermittent hair banding without fragile hair may be related to a gene controlling hair growth dynamics instead of hair structure, such as keratins or keratin-associated proteins2. However, some abnormal weathering patterns have been reported in cases of PA, such as mild indentations to severe longitudinal folding in some hair shafts2, 3, 4, 5. Thus, the air filled spaces in cases of PA may be the reason for hair fragility, which would increase susceptibility to shearing stress4.

The scanning electron microscopic examination in our case revealed mild indentations or longitudinal cracking of the hair cortex, which is observed frequently in typical cases of PA. These findings could be the result of uneven compression of the hair shaft caused by the underlying air spaces4. Some severely damaged hair had multiple white nodes on the hair shaft or longitudinal fissures on the surface that exposed the microfibers of the cortex, which is usually observed in trichorrhexis nodosa. In particular, the nodes associated with the underlying air-filled cavities in a patient with PA may be the focus for the structural damage by environmental trauma4.

In conclusion, it is postulated that heavy use of hair dryer in our patient could have severely traumatized his underlying PA and caused multiple fragile hairs.


CONFLICTS OF INTEREST:The authors have nothing to disclose.

1. Giehl KA, Dean D, Dawber RP, Leigh I, de Berker DA, Wojnarowska F. Cytokeratin expression in pili annulati hair follicles. Clin Exp Dermatol 2005;30:426–428.
2. Giehl KA, Ferguson DJ, Dawber RP, Pittelkow MR, Foehles J, de Berker DA. Update on detection, morphology and fragility in pili annulati in three kindreds. J Eur Acad Dermatol Venereol 2004;18:654–658.
3. Akoglu G, Emre S, Metin A, Erbil KM, Akpolat D, Firat A, et al. Pili annulati with fragility: electron microscopic findings of a case. Int J Trichology 2012;4:89–92.
4. Feldmann KA, Dawber RP, Pittelkow MR, Ferguson DJ. Newly described weathering pattern in pili annulati hair shafts: a scanning electron microscopic study. J Am Acad Dermatol 2001;45:625–627.
5. Werner K, St-Surin-Lord S, Sperling LC. Pili annulati associated with hair fragility: cause or coincidence? Cutis 2013;91:36–38.