Description

This blog was written by Maha Aladwan, a master's student in the Department of Biological Sciences at Western Illinois University.

Piedra is an asymptomatic superficial fungal infection of the hair shaft which leads to 

breakage of the hair itself. The first isolated case of black piedra was in 1876 in Colombia by 

Ozorio and Arango, and the fungus was cultured by Desenne in 1878 (3). Then,  Horta (1911) 

claimed that there were two types of piedra. The first type is black piedra, which is caused by 

Piedraia hortae. The second type is white piedra. Black piedra affects scalp hair, beard, 

mustache and pubic hair. The phylum of the causing agent is Ascomycota. In addition, black 

piedra is most common in the tropical regions of the World that have high temperatures and 

humidity, such as South American, Brazil and Southeast Asia (3-7).


 The macroscopic features of  black piedra are slow growing colonies, folded, small and dark brown. Also, they are covered with short aerial hyphae ( Figure 1). Black piedra produce a reddish brown diffusible pigment (Fonseca and de Area Leao in 1928). Microscopic features are septate hyphae, asci, and ascostromata. Hyphae are dark and have chlamydoconidium-like cells (doctor fungus). The Ascostromata is a pseudoparenchymatous structures that are black in color and the asci are ellipsoid, solitary and contain 8 ascospores. Ascospores are hyaline to darkly pigmented and contained one-celled (3).

Figure 1: Black piedra have folded, small and dark brown and short hyphae.