An ultrastructural study on corkscrew hairs and cigarette-ash-shaped hairs observed by dermoscopy of tinea capitis.

This study was aimed to explain the formation mechanisms of corkscrew hairs and cigarette-ash-shaped hairs observed by dermoscopy of tinea capitis. In the present work, the ultrastructure of the involved hairs collected from a girl with tinea capitis caused by Trichophyton violaceum was observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). SEM observation of the corkscrew hair revealed bent hair shaft and asymmetrically disrupted cuticle layer. TEM findings demonstrated the hair shaft became weak. The corkscrew hairs closely covered by scales on the scalp were observed under dermoscopy. We speculate that the formation of corkscrew hairs is a result of a combination of internal damage due to hair degradation by T. violaceum and external resistance due to scales covering the hair. SEM observation of the cigarette-ash-shaped hair revealed irregularly disrupted and incompact end, which might represent the stump of the broken corkscrew hair after treatment.

[1]  F. Lacarrubba,et al.  Newly described features resulting from high-magnification dermoscopy of tinea capitis. , 2015, JAMA dermatology.

[2]  Ö. Ekiz,et al.  Trichoscopy in Paediatric Patients with Tinea Capitis: A Useful Method to Differentiate from Alopecia Areata , 2014, Journal of the European Academy of Dermatology and Venereology : JEADV.

[3]  Y. Ran,et al.  Scanning and transmission electron microscopic observation of the parasitic form of Trichophyton violaceum in the infected hair from tinea capitis. , 2014, Scanning.

[4]  M. Starace,et al.  Corkscrew hair: a trichoscopy marker of tinea capitis in an adult white patient. , 2013, JAMA dermatology.

[5]  G. Argenziano,et al.  Dermoscopic corkscrew hairs dissolve after successful therapy of Trichophyton violaceum tinea capitis: A case report , 2012, The Australasian journal of dermatology.

[6]  A. Cerri,et al.  Comma Hairs in Tinea Capitis: A Useful Dermatoscopic Sign for Diagnosis of Tinea Capitis , 2012, Pediatric dermatology.

[7]  Ana Maria Costa Pinheiro,et al.  Dermoscopy findings in tinea capitis: case report and literature review. , 2012, Anais brasileiros de dermatologia.

[8]  W. Momani,et al.  Cases of tinea capitis as encountered in a private practice laboratory from Jordan. , 2011 .

[9]  C. Chiaverini,et al.  Corkscrew hair: a new dermoscopic sign for diagnosis of tinea capitis in black children. , 2011, Archives of dermatology.

[10]  Chao Zhang,et al.  Tinea Capitis in Southeastern China: A 16-Year Survey , 2010, Mycopathologia.

[11]  R. Schwartz,et al.  Comma hairs: a dermatoscopic marker for tinea capitis: a rapid diagnostic method. , 2008, Journal of the American Academy of Dermatology.

[12]  M. Quadroni,et al.  Comprehensive analysis of proteins secreted by Trichophyton rubrum and Trichophyton violaceum under in vitro conditions. , 2007, Journal of proteome research.

[13]  Ruoyu Li,et al.  Current topics of tinea capitis in China. , 2005, Nihon Ishinkin Gakkai zasshi = Japanese journal of medical mycology.

[14]  S. de Hoog,et al.  Origins of Microsatellite Diversity in the Trichophyton rubrum- T. violaceum Clade (Dermatophytes) , 2004, Journal of Clinical Microbiology.

[15]  K. Wawrzkiewicz,et al.  Screening the keratinolytic activity of dermatophytes in vitro , 1991, Mycopathologia.

[16]  O. Jousson,et al.  Secreted proteases from pathogenic fungi. , 2002, International journal of medical microbiology : IJMM.

[17]  M. Maslen.  Human cases of cattle ringworm due to Trichophyton verrucosum in Victoria, Australia , 2000, The Australasian journal of dermatology.

[18]  A. H. Aubaid,et al.  Extracellular enzyme activities of dermatophytes and yeast isolates on solid media , 1997, Mycoses.

[19]  J. Y. Lee,et al.  Pathogenesis of hair infection and black dots in tinea capitis caused by Trichophyton violaceum: a histopathological study , 1992, Journal of cutaneous pathology.

[20]  M. Ito,et al.  Fungus invasion into human hair tissue in black dot ringworm: light and electron microscopic study. , 1988, The Journal of investigative dermatology.

[21]  W. Shelley,et al.  The infected hairs of tinea capitis due to Microsporum canis: demonstration of uniqueness of the hair cuticle by scanning electron microscopy. , 1987, Journal of the American Academy of Dermatology.