Materia. erial - Taylor & Francis

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1 12 Infections Antonella Tosti TINEA CAPITIS Box 12.1 Tinea Capitis Common fungal infection, especially among children. Diagnosis is based on direct microscopic examinations and mycological cultures. Scalp Cscaling and alopecia due to hair breakage. Lymph node enlargement. Dermoscopy: comma hairs, corkscrew hairs, black dots, broken hairs, hair casts, and transverse white bands. Copyrighted Hair invasion by dermatophytes es has a different epidemiology depending on the causative agent. Trichophyton species cause endothrix tinea capitis, which Mich is the most common type in North America (Trichophyton tonsurans) and in Eastern and Southern Europe, and North Africa (Trichophyton violaceum). It affects both children and adults, transmission is interhuman and asymptomatic carriers are frequent. Microsporum canis causes ectothrix tinea capitis, which is common in Western Europe and almost exclusively affects children. Transmission occurs through a symptomatic or asymptomatic animal, usually a cat. Scalp scaling is a prominent feature in all types of tinea capitis. Tinea capitis produces patches of alopecia due to breakage of the hair shafts at the scalp level in endothrix infections or at 1 3 mm from scalp emergence in ectothrix infections. Pustular lesions may be observed in inflammatory tinea capitis (kerion). Cervical nodes are often enlarged. The dermoscopic marker of tinea capitis is comma hairs, which appear as short C-shaped hairs due to bending of the hair shaft filled with fungi. Corkscrew hairs are seen in patients of African descent due to the shape of the broken hair shaft, which has a corkscrew or coiled appearance. Black dots, broken hairs, hair casts, and horizontal white bands ( Morse-code hairs) may also be observed. Materia erial - Taylor & Francis Figure 12.1 (a c) Comma and corkscrew hairs in tinea capitis of patients of African descent. 117

2 tosti Copy Figure 12.2 (a, b) Comma hairs and horizontal white bands. Copyrigh ighted Materia rial - Taylor Tay ayl Figure 12.3 Comma hairs and hair casts. PIEDRA Box 12.2 Piedra Superficial mycoses of the hair shaft that can cause hair breakage White piedra: yellow white fusiform nodules Black piedra: irregular, dark, pebble-sized nodules Dermoscopy: white or black concretions on the hair shaft & sfrancis Fra s s White piedra is caused by Trichosporon asahii and five other species of Trichosporon,, a fungus that invades the hair shaft of pubic hairs, but it can involve the beard and scalp hair. The hair shaft is covered by soft yellow white fusiform nodules, which are easily detachable. Black piedra is caused by Piedraia a cissurrou hortae,, a fungus that penetrates the cuticle, grows and then surrounds spi the hair shaft with hyphae. It mostly occurs in tropical regions and usually affects scalp hair. The clinical presentation consists of black, firmly attached, hard nodules on the scalp, beard, and body hair. Dermoscopy shows white or black concretions on the hair shaft. 118

3 infections Copyrighted Material - Taylor & Fran ancis Figure 12.4 White piedra affecting the scalp of a Brazilian patient (a). (Courtesy of Dr. Nilton Di Chiacchio, Brazil.) Dermoscopy shows regular fusiform concretions surrounding the hair shaft (b d). (Courtesy of Dr. Fernanda Torres, Brazil.) 119

4 tosti Copyrighted Material distributed- Taylor & Francis Figure 12.5 (a, b) White piedra: white, irregularly Matedistributed fusiform nodules surrounding the hair shafts. (Courtesy of Dr. Lorena Dorado, Brazil.) Figure 12.6 White piedra in a Brazilian woman with minimal clinical lesions (a). Diagnosis is confirmed by dermoscopy (b). (Courtesy of Dr. Leonardo Spagnol Abraham, Brazil.) 120

5 infections SUGGESTED READINGS Haliasos EC, Kerner M, Jaimes-Lopez N, Rudnicka L, Zalaudek I, Malvehy J, Hofmann-Wellenhof R, Braun RP, Marghoob AA. Dermoscopy for the pediatric dermatologist part I: Dermoscopy of pediatric infectious and inflammatory skin lesions and hair disorders. Pediatr Dermatol Mar Apr;30(2): Hughes R, Chiaverini C, Bahadoran P, Lacour JP. Corkscrew hair: A new dermoscopic sign for diagnosis of tinea capitis in black children. Arch Dermatol Mar;147(3): Khatu SS, Poojary SA, Nagpur NG. Nodules on the hair: A rare case of mixed piedra. Int J Trichol Oct;5(4): Pinheiro AM, Lobato LA, Varella TC. Dermoscopy findings in tinea capitis: Case report and literature review. An Bras Dermatol Mar Apr;87(2): Copyrighted Material - Taylor & Francis 121