Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Black piedra
Introduction
Overview
Overview
Black piedra is a form of piedra caused by Piedraia hortae.[1]
Terbinafine has been used in the treatment.[2]
Differential Diagnosis
Differential Diagnosis
Black piedra should be differentiated from other diseases presenting as red, pruritic, annular, scaly rash. The differentials include the following:
| Name of superficial infection | Clinical presentation | Extension to hair follicle | Fungus(i) | Systemic disease | KOH preparations | Morphology in tissue sections |
|---|---|---|---|---|---|---|
| Tinea or ringworm | Round lesions with scaly border, accompanied by pruritis and burning | Yes; when suppurative known as kerion, when chronic known as Majocchi’s granuloma | Dermatophytes (Epidermophyton spp., Trichophyton spp., Microsporum spp.) | Very rare but can invade the dermis and soft tissues, causing mycetomas | Hyphae with or without septations | Hyphae cannot be visualized in the keratin with H&E, special stains are needed |
| Tinea versicolor | Hypo and hyperpigmentation in patients with oily and sweaty skin, fine scales when scratching | Yes, known as Pityrosporum folliculits | Malassezia spp. | Systemic infections may occur in premature neonates receiving parenteral nutrition and in other immunosuppressed hosts | Yeasts and hyphae (“spaghetti and meat balls”) | Faintly basophilic hyphae in the stratum corneum |
| Tinea nigra | Brown to black macule, usually on palms, with some scaling | No | Phaeoannellomyces werneckii | Not described | Darkly pigmented, septated, and branching hyphae | Pigmented hyphae in the stratum corneum |
| White piedra | Creamy-white, small, soft nodules in hair shafts | No | Trichosporon spp. | Immunosuppressed patients may have lung infiltrates, renal involvement, and fungemia | Septate hyphae perpendicular to hair shaft | Not used for diagnosis |
| Black piedra | Hard dark nodules in hair shafts | No | Piedraia hortae | Not described | Collections of crescent ascospores surrounded by pigmented hyphae | Not used for diagnosis |
| Superficial candidiasis | Intertrigo, chronic paronychia, onychodystrophy, cheilitis | Yes | Candida spp. | Yes, particularly in patients with AIDS and depending on the level of immunosuppression | Yeasts, pseudohyphae may be observed | Fungal elements may be seen through the biopsy, vascular invasion must be determined |
Gallery
Gallery
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![Under a relatively-low magnification of 100X, this photomicrograph reveals some of the pathologic morphology displayed by a primate hair shaft indicative of the disease known as, “black piedra”, also known as “trichosporosis”, which is caused by the fungal organism, Piedraia hortae. From Public Health Image Library (PHIL). [3]](https://www.wikidoc.org/images/2/2e/Black_piedra01.jpeg)
Under a relatively-low magnification of 100X, this photomicrograph reveals some of the pathologic morphology displayed by a primate hair shaft indicative of the disease known as, “black piedra”, also known as “trichosporosis”, which is caused by the fungal organism, Piedraia hortae. From Public Health Image Library (PHIL). [3] -
![This is a photomicrograph of a hair shaft with a condition called “black piedra” due to Piedraia hortae. From Public Health Image Library (PHIL). [3]](https://www.wikidoc.org/images/4/47/Black_piedra03.jpeg)
This is a photomicrograph of a hair shaft with a condition called “black piedra” due to Piedraia hortae. From Public Health Image Library (PHIL). [3] -
![This is a photomicrograph of the mycelium of the fungus Piedraia hortae, magnified 475X. From Public Health Image Library (PHIL). [3]](https://www.wikidoc.org/images/4/43/Black_piedra04.jpeg)
This is a photomicrograph of the mycelium of the fungus Piedraia hortae, magnified 475X. From Public Health Image Library (PHIL). [3] -
![This is a plate culture of Piedraia hortae, strain A272. From Public Health Image Library (PHIL). [3]](https://www.wikidoc.org/images/9/9a/Black_piedra05.jpeg)
This is a plate culture of Piedraia hortae, strain A272. From Public Health Image Library (PHIL). [3]
![Under a relatively-low magnification of 100X, this photomicrograph reveals some of the pathologic morphology displayed by a primate hair shaft indicative of the disease known as, “black piedra”, also known as “trichosporosis”, which is caused by the fungal organism, Piedraia hortae. From Public Health Image Library (PHIL). [3]](https://www.wikidoc.org/index.php/File%3ABlack_piedra01.jpeg)
![This is a photomicrograph of a hair shaft with a condition called “black piedra” due to Piedraia hortae. From Public Health Image Library (PHIL). [3]](https://www.wikidoc.org/index.php/File%3ABlack_piedra03.jpeg)
![This is a photomicrograph of the mycelium of the fungus Piedraia hortae, magnified 475X. From Public Health Image Library (PHIL). [3]](https://www.wikidoc.org/index.php/File%3ABlack_piedra04.jpeg)
![This is a plate culture of Piedraia hortae, strain A272. From Public Health Image Library (PHIL). [3]](https://www.wikidoc.org/index.php/File%3ABlack_piedra05.jpeg)
References
References
- ↑ “eMedicine – Piedra : Article by Robert A Schwartz”. Retrieved 2008-11-08.
- ↑ Gip L (1994). “Black piedra: the first case treated with terbinafine (Lamisil)”. The British journal of dermatology. 130 Suppl 43: 26–8. PMID 8186138. Unknown parameter
|month=ignored (help) - ↑ 3.0 3.1 3.2 3.3 “Public Health Image Library (PHIL)”.