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117
InfectionsAntonella Tosti
TINEA CAPITIS
Hair invasion by dermatophytes has a di�erent epidemi-ology depending on the causative agent. Trichophyton species cause endothrix tinea capitis, which is the most common type in North America (Trichophyton ton-surans) and in Eastern and Southern Europe, and North
Africa (Trichophyton violaceum). It a�ects both children and adults, transmission is interhuman and asymptom-atic carriers are frequent.
Microsporum canis causes ectothrix tinea capitis, which is common in Western Europe and almost exclu-sively a�ects 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 sha�s at the scalp level in endothrix infections or at 1–3 mm from scalp emergence in ectothrix infections. Pustular lesions may be observed in in�am-matory tinea capitis (kerion). Cervical nodes are o�en enlarged.
�e dermoscopic marker of tinea capitis is comma hairs, which appear as short C-shaped hairs due to bend-ing of the hair sha� �lled with fungi. Corkscrew hairs are seen in patients of African descent due to the shape of the broken hair sha�, which has a corkscrew or coiled appear-ance. Black dots, broken hairs, hair casts, and horizontal white bands (“Morse-code” hairs) may also be observed.
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Box 12.1 Tinea Capitis
• Common fungal infection, especially among children.
• Diagnosis is based on direct microscopic exam-inations and mycological cultures.
• Scalp scaling and alopecia due to hair breakage.• Lymph node enlargement.• Dermoscopy: comma hairs, corkscrew hairs,
black dots, broken hairs, hair casts, and trans-verse white bands.
Figure 12.1 (a–c) Comma and corkscrew hairs in tinea capitis of patients of African descent.
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inations and mycological cultures.Copyrighted
inations and mycological cultures.Copyrighted
Copyrighted air invasion by dermatophytes has a di�erent epidemi
Copyrighted air invasion by dermatophytes has a di�erent epidemi
ology depending on the causative agent.
Copyrighted ology depending on the causative agent. species cause endothrix tinea capitis, which is the most
Copyrighted species cause endothrix tinea capitis, which is the most
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Scalp scaling and alopecia due to hair breakage.Copyrighted
Scalp scaling and alopecia due to hair breakage.Lymph node enlargement.
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Lymph node enlargement.Dermoscopy: comma hairs, corkscrew hairs,
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Dermoscopy: comma hairs, corkscrew hairs, black dots, broken hairs, hair casts, and trans
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black dots, broken hairs, hair casts, and transverse white bands.
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verse white bands.
Material
TrichophytonMaterial
Trichophytonspecies cause endothrix tinea capitis, which is the most Material
species cause endothrix tinea capitis, which is the most Trichophyton tonMaterial
Trichophyton ton) and in Eastern and Southern Europe, and North
Material
) and in Eastern and Southern Europe, and North
Material - Taylor & Francis
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PIEDRAWhite piedra is caused by Trichosporon asahii and �ve other species of Trichosporon, a fungus that invades the hair sha� of pubic hairs, but it can involve the beard and scalp hair. �e hair sha� is covered by so� yellow–white fusiform nodules, which are easily detachable.
Black piedra is caused by Piedraia hortae, a fungus that penetrates the cuticle, grows and then surrounds the hair sha� with hyphae. It mostly occurs in tropical regions and usually a�ects scalp hair. �e clinical presentation con-sists of black, �rmly attached, hard nodules on the scalp, beard, and body hair.
Dermoscopy shows white or black concretions on the hair sha�.
Box 12.2 Piedra
• Super�cial mycoses of the hair sha� 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 sha�
Figure 12.2 (a, b) Comma hairs and horizontal white bands.
Figure 12.3 Comma hairs and hair casts.
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a, b) Comma hairs and horizontal white bands.
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a, b) Comma hairs and horizontal white bands.
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Material - Taylor Figure 12.3
Taylor Figure 12.3 C
Taylor Comma hairs and hair casts.
Taylor omma hairs and hair casts.
& White piedra is caused by & White piedra is caused by
Trichosporon
& TrichosporonFrancis
Trichosporon asahiiFrancis
Trichosporon asahiiTrichosporonFrancis
Trichosporon, a fungus that invades the Francis
, a fungus that invades the hair sha� of pubic hairs, but it can involve the beard and
Francishair sha� of pubic hairs, but it can involve the beard and scalp hair. �e hair sha� is covered by so� yellow–white
Francisscalp hair. �e hair sha� is covered by so� yellow–white fusiform nodules, which are easily detachable.
Francisfusiform nodules, which are easily detachable.
Piedraia hortae
FrancisPiedraia hortae, a fungus that
Francis , a fungus that penetrates the cuticle, grows and then surrounds the hair
Francispenetrates the cuticle, grows and then surrounds the hair sha� with hyphae. It mostly occurs in tropical regions and
Francissha� with hyphae. It mostly occurs in tropical regions and
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Figure 12.4 White piedra a�ecting the scalp of a Brazilian patient (a). (Courtesy of Dr. Nilton Di Chiacchio, Brazil.) Dermoscopy shows regular fusiform concretions surrounding the hair sha� (b–d). (Courtesy of Dr. Fernanda Torres, Brazil.)
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Francishite piedra a�ecting the scalp of a Brazilian patient (a). (Courtesy of Dr. Nilton Di Chiacchio, Brazil.)
Francishite piedra a�ecting the scalp of a Brazilian patient (a). (Courtesy of Dr. Nilton Di Chiacchio, Brazil.)
FrancisDermoscopy shows regular fusiform concretions surrounding the hair sha� (b–d). (Courtesy of Dr. Fernanda Torres,
FrancisDermoscopy shows regular fusiform concretions surrounding the hair sha� (b–d). (Courtesy of Dr. Fernanda Torres,
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Figure 12.5 (a, b) White piedra: white, irregularly distributed fusiform nodules surrounding the hair sha�s. (Courtesy of Dr. Lorena Dorado, Brazil.)
Figure 12.6 White piedra in a Brazilian woman with minimal clinical lesions (a). Diagnosis is con�rmed by dermoscopy (b). (Courtesy of Dr. Leonardo Spagnol Abraham, Brazil.)
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Material a, b) White piedra: white, irregularly distributed fusiform nodules surrounding the hair sha�s. (Courtesy
Material a, b) White piedra: white, irregularly distributed fusiform nodules surrounding the hair sha�s. (Courtesy
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SUGGESTED READINGSHaliasos EC, Kerner M, Jaimes-Lopez N, Rudnicka L,
Zalaudek I, Malvehy J, Hofmann-Wellenhof R, Braun RP, Marghoob AA. Dermoscopy for the pediatric der-matologist part I: Dermoscopy of pediatric infectious and in�ammatory skin lesions and hair disorders. Pediatr Dermatol. 2013 Mar–Apr;30(2):163–71.
Hughes R, Chiaverini C, Bahadoran P, Lacour JP. Corkscrew hair: A new dermoscopic sign for diagnosis
of tinea capitis in black children. Arch Dermatol. 2011 Mar;147(3):355–6.
Khatu SS, Poojary SA, Nagpur NG. Nodules on the hair: A rare case of mixed piedra. Int J Trichol. 2013 Oct;5(4):220–3.
Pinheiro AM, Lobato LA, Varella TC. Dermoscopy �nd-ings in tinea capitis: Case report and literature review. An Bras Dermatol. 2012 Mar–Apr;87(2):313–4.
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