1- الفطريات السطحية Superficial Mycoses Incidence Causative organisms Disease Rare Exophiala werneckii     Tinea nigra Common Trichosporon beigelii White piedra Piedraia hortae   Black piedra Malassezia furfur  (a lipophilic yeast) Pityriasis versicolor Seborrhoeic dermatitis  including Dandruff and Follicular pityriasis Text slide.

Black piedra 2- فطر البصرية Piedraia piedra hortae المسبب:- الأعراض:- يسبب هذا الفطر عقد ورمية سوداء صلبة nodules حول بصيلات شعر الرأس وهذا ما يعرف black piedra البصرة السوداء تتميز بارتباطها الشديد حول بصلة الشعر. الإنتشار:- المناطق المدارية مثل جنوب امريكا.

Black piedra الصفات المورفولوجية:- يسبب هذا الفطر - عقد nodules ورمية سوداء. - صلبة. - حول جذر شعر الرأس وهذا ما يعرف black piedra الخيوط الفطرية والأبواغ توجد في المحيط الخارجي للعقدة. الصفات التشريحية:- افة سطحية تصيب خصلة الشعر ولا تسبب تساقطه.

Black piedra المظهر الإكلينيكي :- عقد سوداء وتختلف عن white piedra بأنها ترتبط بقوة في بصيلات الشعر. مكان الآفة :- فروة الرأس. التشخيص :- فحص الشعر المتأثر تحت المجهر بعد معامله بـ KOH التفريق:- القمل Lice , white piedra .

This is a higher magnification photograph of hair with black piedra This is a higher magnification photograph of hair with black piedra. The lesion is very discrete, surrounds the hair shaft and is dark brown. Eventually the fungus may weaken the hair shaft to the extent that the hair breaks off.

This is a still higher magnification of hair infected with Piedraia hortai. Close observation reveals that the nodule appears to be composed of hundreds of spherical cells. These cells are the asci, which contains ascospores. Such structures can be seen more clearly when one places infected hair in 1-2 drops of 10-20% KOH on a microscope slide, adds a coverslip, heats the preparation gently and the presses down very firmly on the coverslip. In such preparations the piedra nodules break open, and one sees many individual asci containing ascospores and, occasionally, groups of ascospores which have been squeezed out of individual asci.

This is a culture of the fungus Piedraia hortai This is a culture of the fungus Piedraia hortai. This fungus was cultured on Sabourauds medium and incubated at room temperature. It normally takes 4-6 weeks incubation weeks incubation for a colony to reach this size. The gross features of this colony are that it is slow-growing, is heaped up in the center, is a dark brown-black to metallic green and is surrounded by a clear ring where the young growing mycelium has not yet produced the dark pigment. Microscopically, there are few characteristic features. The fungus produces dermatiaceous hyphae which may contain numerous chlamydospores. No characteristic spores are produced.

                                                     Black Piedra. Piedraia hortae forms a hard superficial pigmented nodule around the hair shaft.

Piedraia hortae Title: Black piedra Disease(s): Piedra, black Legend: Ascomycete fruiting body on a human hair. Genus/Species: Piedraia hortae Image Type: Macroscopic Morphology

                                                     Black Piedra. Piedraia hortae forms a hard superficial pigmented nodule around the hair shaft.

                                                     Black Piedra. Piedraia hortae forms a hard superficial pigmented nodule around the hair shaft.