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Piedra


Synonyms

None

Definition

Piedra refers to colonization of the hair shaft that results in firm, irregular nodules. If the nodule is dark, the infection is Black Piedra and is due to Piedra iahortae. The nodule is the ascomycete fruiting body of the fungus, know as an ascostroma. If the nodule is white, the infection is White Piedra and is due to Trichosporon beigelii. These nodules are a loose aggregate of hyphae and arthroconidia. Multiple colonization of the same strand are common. The infection may affect hairs of the scalp, body and genital areas [741, 1145, 2155]. The source of infection is unknown and even though person to person transmission has been suggested, it rarely occurs [884, 1145, 1447].

Clinical manifestations

Both clinical varieties are mostly asymptomatic. However, according to the severity of the infection, progressive weakness of the hair shaft will occur causing breaks.

In black piedra, brown to black nodules will be firmly adherent to the shaft and cannot be readily detached. The area most frequently involved is the scalp. Indeed, a metallic sound may be heard when the hair is combed.

In white piedra, the nodules are easily detached from the hair shaft by rubbing along its length. Their color varies from white to light brown. Pubic hair, beard and mustache are the most commonly infected areas [1447].

Disseminated infections due to T. beigelli, another Trichosporon species, have been described among immunosuppressed hosts [238, 1028, 1678].

Differential diagnosis for both conditions includes pediculosis capitis, pubis louse infestations, trichorrhexis nodosa, trichomycosis axillaris and monilothrix [884].

Prognosis and therapy

Therapy includes shaving of affected areas or topical application of salycylic acid, 2% formaldehyde or azole creams. Oral therapy with either ketoconazole or terbinafine has also been used. However, relapse rates are high even after adequate therapy [842, 1145].

Mycology
Natural habitat

Ubiquitous



Hair with Black Piedra
Hair with black Piedra



References

238. Bhansali, S., C. Karanes, W. Palutke, L. Crane, R. Kiel, and V. Ratanatharathorn. 1986. Successful treatment of disseminated Trichosporon beigelii (cutaneum) infection with associated splenic involvement. Cancer. 58:1630-2.

741. Fishman, H. C. 1987. White piedra. Int. J. Dermatol. 26:538.

842. Gip, L. 1994. Black piedra: the first case treated with terbinafine (Lamisil). Br J Dermatol. 130 Suppl 43:26-8.

884. Grainger, C. R. 1986. White piedra: a case with evidence of spread by contact. Trans R Soc Trop Med Hyg. 80:87.

1028. Henwick, S., K. Henrickson, S. A. Storgion, and R. J. Leggiadro. 1992. Disseminated neonatal Trichosporon beigelii. Pediatr. Infect. Dis. J. 11:50-52.

1145. Kalter, D. C., J. A. Tschen, P. L. Cernoch, M. E. McBride, J. Sperber, S. Bruce, and J. E. Wolf, Jr. 1986. Genital white piedra: epidemiology, microbiology, and therapy. J Am Acad Dermatol. 14:982-93.

1447. Martin, A. G., and G. S. Kobayashi. 1993. Fungal diseases with cutaneous involvement, p. 2421-2451. In T. B. Fitzpatrick (ed.), Dermatology in general medicine, vol. 2. McGraw-Hill, New York.

1678. Ogata, K., Y. Tanabe, K. Iwakiri, T. Ito, T. Yamada, K. Dan, and T. Nomura. 1990. Two cases of disseminated Trichosporon beigelii infection treated with combination antifungal therapy. Cancer. 65:2793-5.

2155. Steinman, H. K., and R. B. Pappenfort. 1984. White piedra--a case report and review of the literature. Clin Exp Dermatol. 9:591-8.



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