41. laboratory diagnosis of common fungal diseases

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  • Cutaneous mycoses are fungal infections of the integument and its appendages. They are superficial infections of the skin, hair & nails The fungus localizes only in the cornified layer, stratum corneum, No living tissue is invaded Pathological changes occur in the host because of her reaction to the fungus and its products of metabolism or life. A llergic & inflammatory eczematous host response
  • Dermatophytosis are caused by a closely related group of organisms, called dermatophytes Which are keratinophilic Very similar & closely related group of fungi that cause a wide variety of clinical conditions A single species may be involved in several disease types, each with its distinctive pathology Most commonest infectious agents of man, the infections are distributed worldwide (geographically & racially) Common term is ringworm
  • Dermatomycosis are skin infections that are caused neither by dermatophytes nor by the genus candida. They may be caused by soil inhabiting fungi
  • Tinea capitis is a dermatophyte infection of the scalp, eyebrows and eyelashes caused by species of Microsporum and Trichophyton. type & severity of response is related to the species & strain of dermatophyte causing infection
  • Tinea capitis is a dermatophyte infection of the scalp, eyebrows and eyelashes caused by species of Microsporum and Trichophyton. type & severity of response is related to the species & strain of dermatophyte causing infection
  • Favus refers to the similarity of appearance of scutula and honeycombs. Favus is characterized by the occurrence of dense masses of mycelium & epithelial debris which form yellowish, cup-shaped crusts called SCUTULA. The scutulum develops in a hair follicle, with the hair shaft in the center of the raised lesion. Removal of these crusts reveals an oozing, moist red base. After a period of years, atrophy of the skin occurs, leaving a cicatricial alopecia & scarring. Scutula may be formed on the scalp or the glabrous skin.
  • Tinea corporis is a dermatophyte infection of the glabrous skin most commonly caused by species of the gnera Trichophyton and Microsporum . The infection is generally restricted to the stratum corneum of the epidermis. The clinical symptoms are a result of the fungal metabolites acting as toxins & allergens. Lesions vary from simple scaling, scaling with erythema & vesicles, to deep granulomata. Villous hair in the involved area may be invaded, & the follicle often acts as a reservoir for recrudescence of the disease.
  • Tinea corporis is a dermatophyte infection of the glabrous skin most commonly caused by species of the gnera Trichophyton and Microsporum . The infection is generally restricted to the stratum corneum of the epidermis. The clinical symptoms are a result of the fungal metabolites acting as toxins & allergens. Lesions vary from simple scaling, scaling with erythema & vesicles, to deep granulomata. Villous hair in the involved area may be invaded, & the follicle often acts as a reservoir for recrudescence of the disease.
  • Tinea imbricata is a geographically restricted form of tinea corporis caused by Trichophyton concentricum. It is characterized by polycyclic, concentrically arranged rings of papulosquamous patches of scales scattered over and often covering most of the body
  • Tinea barbae is a dermatophyte infection of the bearded areas of the face and neck, and therefore is restricted to adult males.
  • Tinea cruris is a dermatophyte infection of the groin, perineum, & perianal region, which is acute or chronic and generally pruritic. The lesion is sharply demarcated, with a raised, erythematous margin & thin, dry epidermal scaling. The disease is found in all parts of the world but is more prevalent in the tropics. It tends to occur when conditions of high humidity lead to maceration of the crural region. A similar condition may involve the axilla or other intertriginous areas. The disease is more common in men, but frequently involves women, usually when it is transmitted by intimate contact or fomite. It may reach epidemic proportions in athletic teams, troops, ship crews, & inmates of institutions. In such cases, it is probably most commonly transmitted by towels, linens, & clothing. E. Floccosum has been isolated from blankets & sheets as well as rugs & other fomites where it can survive for years as infective arthroconidia.
  • Tinea pedis is a dermatophyte infection of the feet involving particularly the toe webs and soles. The lesions are of several types, varying from mild, chronic, and scaling to acute, exfoliative, pustular, & bullous disease.
  • Most dermatophyte infections of the hand, particularly of the dorsal aspect, are similar to tinea corporis. Tinea manuum refers to those infections in which the interdigital areas & the palmar surfaces are involved & show characteristic pathologic features. Along with tinea pedis, tinea manuum is one of the commoner types of chronic dermatophytosis in the adult. It has been postulated that this is related to the lack of sebaceous glands & their fungistatic lipids in these two areas.
  • Tinea unguium is an invasion of the nail plates by a dermatophyte. Onychomycosis is an infection of the nails caused by nondermatophytic fungi and yeasts. Tinea unguium is of at least 2 types: Superficial white onychomycosis – invasion is restricted to patches or pits on the surface of the nail invasive subungual dermatophytosis (ringworm of the nail), in which the lateral or distal edges of the nail are first involved, followed by establishment of the infection beneath the nail plate.
  • For skin specimen, first clean lesion & periphery with 70% alcohol. Use sterile scalpel or edge of microscope slide, scrape perpendicular to the skin. Scrape around the active edge where the fungus is actively growing. The center of lesion heals first, so the laboratory results are negative using this sample. If the lesion is inflamed or with fissures, clean it with sterile distilled water. Collect skin scrapings in paper envelope or petri dish, or place between 2 slides. Store at room temperature. If patients are young children and are scared of the scalpel, use can use scotch tape to collect specimen for microscopy. Collect moist exudate for candida
  • These Fungi exhibit characteristic structures in clinical specimens that can be seen microscopically using a brightfield or phase contrast microscope. You can prepare a wet mount, a specimen plus sterile water or NSS, or specimen alone, like exudates. We can use potassium hydroxide, from 10 to 30% depending upon the type of specimen, for skin use 10%, for nails use a stronger concentration, 30%. Potassium hydroxide digests or dissolves proteins, fats & carbohydrates, the tissue clears Making the fungal cell wall, which is resistant to alkali, visible. Addition of Parker blue-black ink, will stain the fungal structures, facilitating microscopic examination, fungi appear bluish green. The preparation is passed 2 or 3 times over an alcohol lamp or bunsen burner, to hasten the reaction. If the result is negative, especially in nail scrapings, you can leave the preparation overnight on the lab table, to give time for digestion to occur. View the preparation again the next day. Question: Can you use Parker permanent blue or black ink? YES
  • Microscopic examination
  • Use several media
  • 41. laboratory diagnosis of common fungal diseases

    1. 1. LABORATORY DIAGNOSIS OF COMMON FUNGAL DISEASES Prof. Louella A. Dancel, RMT, MSc. University of Perpetual Help System DALTA 42 nd PAMET ANNUAL CONVENTION Manila Hotel – December 2,2006
    2. 2. Clinical specimens submitted for Fungal Isolation 2004-2006* Clinical specimen 2004 2005 2006 Total Respiratory 29 35 34 98 Body fluids 37 17 34 88 Tissues 9 0 23 32 Skin 1 0 0 1 Nails 29 31 20 80 Hair 0 1 0 1 CSF 8 5 8 21 Others 5 20 24 49 TOTAL 118 109 153 380
    3. 3. Fungal Isolates 2004-2006 * Isolate 2004 2005 2006 C.albicans 5.1% 13.8% 11.8% C.tropicalis 1.8% 3.7% 5.2% C.parapsilosis 5.1% 6.4% 3.9% C.glabrata 0.91% 0.91% 3.9% C.famata 1.8% 4.6% 2.0% Aspergillus spp. 0.91% 0% 0.65% Fusarium spp. 0% 0% 0.65%
    4. 4. Data from a Five-year review of Fungal Isolates at UPM-CPH <ul><li>Clinical specimens (n=545): </li></ul><ul><ul><li>Skin scrapings </li></ul></ul><ul><ul><li>Nail clippings/scrapings </li></ul></ul><ul><ul><li>Hair </li></ul></ul><ul><ul><li>Exudates </li></ul></ul><ul><ul><li>Biopsy materials </li></ul></ul>
    5. 5. Data from a Five-year review of Fungal Isolates at UPM-CPH <ul><li>Total clinical specimens tested – 545 </li></ul><ul><li>Results: </li></ul><ul><li>10.8%- (+) for both KOH & culture </li></ul><ul><li>59.1%- (-) for both KOH &culture </li></ul><ul><li>17.1% - (+)culture, (-) KOH </li></ul><ul><li>12.8% - (-) culture, (+) KOH </li></ul>
    6. 6. Data from a Five-year review of Fungal Isolates at UPM-CPH <ul><li>Fungal isolates : </li></ul><ul><li>Trichophyton mentagrophytes </li></ul><ul><li>Trichophyton rubrum </li></ul><ul><li>Trichophyton tonsurans </li></ul><ul><li>Trichophyton schoenlenii </li></ul><ul><li>Trichosporon spp. </li></ul>
    7. 7. Data from a Five-year review of Fungal Isolates at UPM-CPH <ul><li>Fungal isolates </li></ul><ul><li>Microsporum gypseum </li></ul><ul><li>Microsporum canis </li></ul><ul><li>Epidermophyton flocossum </li></ul><ul><li>Candida albicans </li></ul><ul><li>Exophiala werneckii </li></ul>
    8. 8. Data from a Five-year review of Fungal Isolates at UPM-CPH <ul><li>Fungal isolates from biopsy materials and exudates (31.2% positive): </li></ul><ul><li> Fonsecaea compactum </li></ul><ul><li>Phialophora verrucosa </li></ul><ul><li> Exophiala jeanselmei </li></ul><ul><li>Madurella grisea </li></ul>
    9. 9. Laboratory Methods for Diagnosis of Mycoses <ul><li>I. DIRECT EXAMINATION: </li></ul><ul><li>*10-30% KOH </li></ul><ul><li>*Calcofluor white stain </li></ul><ul><li>*Histological stains- H&E, PAS </li></ul><ul><li>*India Ink </li></ul><ul><li>*Wet mount </li></ul>
    10. 10. Laboratory Methods for Diagnosis of Mycoses <ul><li>II. Isolation & Culture </li></ul><ul><li>SDA </li></ul><ul><li>BHIA/BAP </li></ul><ul><li>Media with/without antibiotics </li></ul><ul><li>Macroscopic examination of culture </li></ul><ul><li>Microscopic examination using LPCB </li></ul>
    11. 11. Laboratory Methods for Diagnosis of Mycoses <ul><li>III. Biochemical Tests: </li></ul><ul><li>* Rapid kits for yeasts </li></ul><ul><li>*Urea test </li></ul><ul><li>IV. Special Tests: </li></ul><ul><li>*In-vitro hair perforation test </li></ul><ul><li> *Germ tube test </li></ul><ul><li>*Chlamydoconidia formation test </li></ul>
    12. 12. Mycotic Infections <ul><li>Superficial </li></ul><ul><li>Cutaneous </li></ul><ul><li>Subcutaneous </li></ul><ul><li>Systemic </li></ul><ul><li>Opportunistic </li></ul><ul><li>*Mycotoxicosis </li></ul><ul><li>*Allergies </li></ul>
    13. 13. Superficial mycoses <ul><li>superficial cosmetic fungal infections of the skin or hair shaft </li></ul><ul><li>no living tissue is invaded </li></ul><ul><li>no cellular response from the host </li></ul><ul><li>no pathological changes </li></ul><ul><li>patients unaware of infection </li></ul>
    14. 14. Superficial mycoses <ul><li>Disease </li></ul><ul><li>SKIN </li></ul><ul><li>Pityriasis versicolor </li></ul><ul><li>Tinea nigra </li></ul><ul><li>Causative organisms </li></ul><ul><li>Malassezia furfur </li></ul><ul><li>Exophiala werneckii </li></ul>
    15. 15. Superficial mycoses <ul><li>Disease </li></ul><ul><li>HAIR </li></ul><ul><li>White piedra </li></ul><ul><li>Black piedra </li></ul><ul><li>Causative organisms </li></ul><ul><li>Trichosporon beigelii </li></ul><ul><li>Piedraia hortae </li></ul>
    16. 16. Pityriasis versicolor <ul><li>Lesion </li></ul><ul><ul><li>-An-an” </li></ul></ul><ul><ul><li>-Hyperpigmented or hypopigmented macular lesions </li></ul></ul>Superficial mycoses www.ethnomed.org
    17. 17. Pityriasis versicolor <ul><li>Lesion </li></ul><ul><ul><li>scale readily, giving a chalky branny appearance </li></ul></ul><ul><ul><li>occurs on the trunk, shoulders & arms, face and neck </li></ul></ul>Superficial mycoses Modified from www.columbia.edu
    18. 18. Pityriasis versicolor <ul><li>Lesion </li></ul><ul><ul><li>fluoresce pale greenish under Wood’s lamp </li></ul></ul><ul><li>Distribution </li></ul><ul><ul><li>worldwide </li></ul></ul><ul><ul><li>more common in tropical than temperate climates </li></ul></ul>Superficial mycoses
    19. 19. Pityriasis versicolor <ul><li>KOH of skin scrapings </li></ul><ul><li>clusters of budding yeast-like cells & short angular hyphal forms </li></ul><ul><li>“ spaghetti and meat balls” </li></ul>Superficial mycoses
    20. 20. Pityriasis versicolor <ul><li>PAS of skin scrapings </li></ul><ul><li>“ spaghetti and meat balls” </li></ul>Superficial mycoses
    21. 21. Pityriasis versicolor <ul><li>Culture of skin scrapings </li></ul><ul><ul><li>Not necessary </li></ul></ul><ul><ul><li>diagnostic microscopic features </li></ul></ul><ul><ul><li>SDA overlaid with peanut oil, olive oil </li></ul></ul>Superficial mycoses
    22. 22. Pityriasis versicolor <ul><li>Etiologic Agent </li></ul><ul><ul><li>Malassezia globosa </li></ul></ul><ul><ul><li>lipophilic yeast </li></ul></ul><ul><ul><li>part of skin normal flora </li></ul></ul>Superficial mycoses
    23. 23. Pityriasis versicolor <ul><li>Treatment </li></ul><ul><ul><li>keratinolytic agents applied locally </li></ul></ul><ul><ul><li>Mild fungicides </li></ul></ul><ul><ul><li>Miconazole </li></ul></ul><ul><ul><li>Selenium sulfide (1%) shampoo </li></ul></ul>Superficial mycoses
    24. 24. Tinea nigra <ul><li>Lesion </li></ul><ul><ul><li>Gray to black well-demarcated macular lesions </li></ul></ul><ul><ul><li>most frequently occurring on the palms of the hand </li></ul></ul><ul><ul><li>non-inflammatory & non-scaling lesions </li></ul></ul>Superficial mycoses 11th.blogspot.com
    25. 25. Tinea nigra <ul><li>Distribution </li></ul><ul><ul><li>world-wide </li></ul></ul><ul><ul><li>more common in tropical regions of Central & South America, Africa, Southeast Asia & Australia </li></ul></ul>Superficial mycoses
    26. 26. Tinea nigra <ul><li>KOH </li></ul><ul><ul><li>pigmented brown to dark olivaceous (dematiaceous) septate hyphal elements & 2-celled yeast cells </li></ul></ul>Superficial mycoses
    27. 27. Tinea nigra <ul><li>Etiologic agent </li></ul><ul><ul><li>Exophiala werneckii </li></ul></ul><ul><ul><li>saprophyte found in soil, compost, humus & wood in humid tropical & sub-tropical regions </li></ul></ul>Superficial mycoses
    28. 28. Tinea nigra <ul><li>Culture on SDA </li></ul><ul><ul><li>initially mucoid, yeast-like & shiny black </li></ul></ul><ul><ul><li>with age: aerial mycelia & dark olive color </li></ul></ul>Superficial mycoses
    29. 29. Tinea nigra <ul><li>Lactophenol cotton blue (LPCB) of culture on SDA </li></ul><ul><ul><li>2-celled, pale brown yeast cells </li></ul></ul><ul><ul><li>darkly pigmented septa (annelides) </li></ul></ul><ul><ul><li>one cell cylindrical, the other cell is spindle-shaped </li></ul></ul><ul><ul><li>occur in aggregated masses </li></ul></ul>Superficial mycoses
    30. 30. Tinea nigra <ul><li>Treatment </li></ul><ul><ul><li>keratinolytic agents (Whitfield’s ointment) </li></ul></ul><ul><ul><li>tincture of iodine, 2% salicylic acid, 3% sulfur </li></ul></ul><ul><ul><li>miconazole nitrate, imidazoles, triazoles </li></ul></ul>Superficial mycoses
    31. 31. Tinea nigra <ul><li>Prevention </li></ul><ul><ul><li>avoid exposure to sources, contaminated material </li></ul></ul>Superficial mycoses
    32. 32. Piedra <ul><li>Fungus infection of the hair shaft </li></ul><ul><li>presence of firm, irregular nodules </li></ul><ul><li>Nodules - fungal elements cemented together along the hair shaft </li></ul><ul><li>Multiple infections of the same strand </li></ul>Superficial mycoses
    33. 33. Piedra <ul><li>Two varieties </li></ul><ul><ul><li>White piedra </li></ul></ul><ul><ul><li>Black piedra </li></ul></ul>Superficial mycoses
    34. 34. Black piedra <ul><li>Lesion </li></ul><ul><ul><li>discrete, hard, gritty, brown to black concretions / nodules </li></ul></ul><ul><ul><li>infection of hair </li></ul></ul><ul><ul><ul><li>scalp hair -common </li></ul></ul></ul><ul><ul><ul><li>beard, moustache - less common </li></ul></ul></ul><ul><ul><ul><li>axilla & groin hairs - rare </li></ul></ul></ul>Superficial mycoses www.doctorfungus.org
    35. 35. Black piedra - distribution Superficial mycoses
    36. 36. Black piedra <ul><li>Etiologic agent </li></ul><ul><ul><li>Piedraia hortae </li></ul></ul><ul><ul><li>source of infection </li></ul></ul>Superficial mycoses
    37. 37. Black piedra - lab diagnosis <ul><li>Direct microscopy </li></ul><ul><ul><li>specimen - hair with nodules </li></ul></ul><ul><ul><li>25% NaOH or KOH </li></ul></ul><ul><ul><li>dark septate hyphae </li></ul></ul>Superficial mycoses
    38. 38. Black piedra - lab diagnosis <ul><li>Direct microscopy </li></ul><ul><ul><li>round to oval asci; hyaline, curved to fusiform ascospores </li></ul></ul>Superficial mycoses
    39. 39. Black piedra - lab diagnosis <ul><li>Isolation – medium </li></ul><ul><ul><li>SDA with chloramphenicol </li></ul></ul><ul><ul><li>SDA  cycloheximide </li></ul></ul>Superficial mycoses
    40. 40. Black piedra - lab diagnosis <ul><li>Isolation </li></ul><ul><li>-growth very slow </li></ul><ul><ul><li>-dark brown to black </li></ul></ul><ul><ul><li>-greenish brown, short aerial mycelium </li></ul></ul>Superficial mycoses Heaped center Flat periphery
    41. 41. White piedra <ul><li>Infection of hair shaft </li></ul><ul><ul><li>face, axilla, genitals - common </li></ul></ul><ul><ul><li>scalp, eyebrows, eyelashes - less common </li></ul></ul>Superficial mycoses
    42. 42. White piedra <ul><li>Infection of hair shaft </li></ul><ul><ul><li>less common </li></ul></ul>Superficial mycoses scalp eyebrow eyelashes
    43. 43. White piedra <ul><li>Nodule </li></ul><ul><li>Soft, white, yellowish, beige or greenish nodule </li></ul><ul><li>Discrete </li></ul><ul><li>more often coalescent, forming an irregular transparent sheath </li></ul>Superficial mycoses
    44. 44. White piedra <ul><li>Distribution </li></ul><ul><ul><li>common in S. America & Asia </li></ul></ul><ul><ul><li>sporadic in N. America & Europe </li></ul></ul><ul><li>Etiologic agent </li></ul><ul><ul><li>Trichosporon beigelii or T. cutaneum </li></ul></ul>Superficial mycoses
    45. 45. White piedra <ul><li>Ecology </li></ul><ul><ul><li>soil, stagnant water </li></ul></ul><ul><ul><li>decaying fruit </li></ul></ul><ul><ul><li>spoiled food </li></ul></ul><ul><ul><li>sputum & body surfaces </li></ul></ul><ul><ul><li>horses </li></ul></ul>Superficial mycoses
    46. 46. White piedra - lab diagnosis <ul><li>Microscopic direct examination </li></ul><ul><ul><li>specimen - hair with nodules </li></ul></ul><ul><ul><li>10% KOH or 25% NaOH + 5% glycerin </li></ul></ul><ul><ul><li>hyaline septate hyphae </li></ul></ul><ul><ul><li>oval or rectangular arthroconidia </li></ul></ul><ul><ul><li>occasional blastoconidia </li></ul></ul>Superficial mycoses
    47. 47. White piedra - lab diagnosis <ul><li>Isolation </li></ul><ul><li>medium - SDA with chloramphenicol without cycloheximide </li></ul><ul><li>growth/culture </li></ul><ul><ul><li>rapid </li></ul></ul><ul><ul><li>cream-colored, soft </li></ul></ul><ul><ul><li>membranous, wrinkled radial furrows, irregular folding </li></ul></ul>Superficial mycoses
    48. 48. White piedra - lab diagnosis <ul><li>Isolation </li></ul><ul><li>microscopic exam of culture </li></ul><ul><ul><li>hyaline hyphae </li></ul></ul><ul><ul><li>arthroconidia </li></ul></ul><ul><ul><li>blastoconidia </li></ul></ul>Superficial mycoses
    49. 49. White piedra - lab diagnosis <ul><li>Physiological studies </li></ul><ul><ul><li>does not ferment carbohydrates </li></ul></ul><ul><ul><li>assimilate dextrose, lactose, D-xylose, inositol </li></ul></ul><ul><ul><li>negative KNO 3 assimilation </li></ul></ul><ul><ul><li>urease positive </li></ul></ul><ul><ul><li>arbutin is split </li></ul></ul>Superficial mycoses
    50. 50. Piedra - Treatment <ul><li>Shaving or cutting infected hair </li></ul><ul><li>Topical fungicides </li></ul><ul><ul><li>1:200 bichloride of mercury </li></ul></ul><ul><ul><li>benzoic acid & salicylic acid combinations </li></ul></ul><ul><ul><li>3% sulfur ointment </li></ul></ul><ul><ul><li>2% formalin </li></ul></ul>Superficial mycoses
    51. 51. Cutaneous mycoses <ul><li>No living tissue </li></ul><ul><li>Host Rxn to fungus </li></ul>skin hair nails keratinase
    52. 52. Cutaneous mycoses <ul><li>Disease </li></ul><ul><li>Dermatophytosis </li></ul><ul><li>Causative organisms </li></ul><ul><li>Dermatophytes </li></ul><ul><li>Microsporum </li></ul><ul><li>Trichophyton </li></ul><ul><li>Epidermophyton </li></ul>ringworm
    53. 53. Cutaneous mycoses <ul><li>Disease </li></ul><ul><li>Candidiasis of skin, mucous membranes & nails </li></ul><ul><li>Causative organisms </li></ul><ul><li>Candia albicans & related species </li></ul><ul><li>dermatomycosis </li></ul><ul><li>Soil fungi (Scytalidium, Fusarium, etc.) </li></ul><ul><li>Systemic fungi ( Histoplasma, etc) </li></ul>
    54. 54. <ul><li>Ecological Groups of </li></ul><ul><li>Dermatophytes </li></ul>
    55. 55. Geophilic <ul><li>inhabit soil where they decompose keratinaceous debris </li></ul><ul><li>Dead animals </li></ul>
    56. 56. Zoophilic <ul><li>parasitic on animals </li></ul>www.saanendoah.com www.kolumbus.fi
    57. 57. Anthropophilic fungi <ul><li>primarily parasitic to man </li></ul><ul><li>man as exclusive host </li></ul><ul><li>for maintenance & dissemination of species </li></ul>
    58. 58. Anthropophilic fungi <ul><li>Anthropophilic fungi: </li></ul><ul><ul><li>Examples: </li></ul></ul><ul><ul><ul><li>M. audonii </li></ul></ul></ul><ul><ul><ul><li>T. rubrum </li></ul></ul></ul><ul><ul><ul><li>T. schoenleinii </li></ul></ul></ul><ul><ul><ul><li>T. tonsurans </li></ul></ul></ul><ul><ul><ul><li>T. violaceum </li></ul></ul></ul>
    59. 59. Classification of Dermatophytes
    60. 60. Microsporum Macroconidia Rough walled Microconida present
    61. 61. Trichophyton Macroconidia Smooth walled Microconidia present
    62. 62. Epidermophyton Chlamydoconidia Macroconidia Smooth walled Microconidia none
    63. 63. <ul><li>Clinical Manifestations of Dermatophytes </li></ul>
    64. 65. Tinea capitis www.emedicinehealth.com <ul><li>Scalp, eyebrow, eyelashes </li></ul><ul><li>Microsporum & Trichophyton </li></ul>
    65. 66. Tinea capitis <ul><li>Endothrix </li></ul><ul><li>Ectothrix </li></ul>
    66. 67. Tinea favosa <ul><li>Scutulum </li></ul><ul><li>Mass of mycelia & epithelial debris </li></ul><ul><li>Cup shaped crusts </li></ul>www.mf.uni-lj.si
    67. 68. Tinea corporis <ul><li>Non-hairy skin </li></ul><ul><li>Rings with scaly centers </li></ul><ul><li>Rxn vs fungus </li></ul>www.cut.ee/
    68. 69. Tinea corporis <ul><li>E. floccosum </li></ul><ul><li>Trichophyton </li></ul><ul><li>Microsporum </li></ul>
    69. 70. Tinea imbricata Cutaneous <ul><li>Concentric rings </li></ul><ul><li>Trichophyton concentricum </li></ul>
    70. 71. Tinea barbae <ul><li>Bearded areas of face & neck </li></ul>Cutaneous www.merck.com www.emedicine.com
    71. 72. Tinea cruris Cutaneous www.dermnetnz.org <ul><li>Jock itch </li></ul><ul><li>Moist groin area </li></ul><ul><li>E. floccosum, T. rubrum </li></ul>
    72. 73. Tinea pedis Cutaneous www.doctorfungus.org dermatologie.free.fr <ul><li>Athlete’s foot </li></ul><ul><li>Toe webs & soles, even nails </li></ul><ul><li>Id reaction, circulating fungal antigens </li></ul>
    73. 74. Tinea manuum <ul><li>Interdigital areas & palmar surfaces </li></ul>Cutaneous www.dermnetnz.org
    74. 75. Tinea unguium Cutaneous www.dermnetnz.org <ul><li>Invasion of nail plate by dermatophytes </li></ul><ul><li>Thickened, discolored & brittle </li></ul><ul><li>Onychomycosis- non dermatophyte </li></ul><ul><li>Yeast etc. </li></ul>
    75. 76. Laboratory diagnosis
    76. 77. Skin scraping specimen Wipe with water www.doctorfungus.org scalpel Paper / envelope active edge
    77. 78. Direct Examination <ul><li>Wet mount </li></ul><ul><li>KOH </li></ul><ul><ul><li>10% to 30% </li></ul></ul><ul><ul><li>with Parker Superquink blue-black ink </li></ul></ul><ul><ul><li>gentle warming </li></ul></ul>KOH parker
    78. 79. KOH of skin scrapings Cutaneous Septate hypha
    79. 80. KOH of skin scrapings Cutaneous arthrospores septate hypha
    80. 81. Ectothrix invasion of hair <ul><li>Hair invasion </li></ul><ul><li>formation of arthroconidia on the outside of hair shaft </li></ul><ul><li>cuticle of hair is destroyed </li></ul>Cutaneous
    81. 82. Ectothrix invasion of hair <ul><li>Hair invasion by a dermatophyte </li></ul><ul><ul><li>Microsporum canis </li></ul></ul><ul><ul><li>M. gypseum </li></ul></ul><ul><ul><li>Trichophyton equinum </li></ul></ul><ul><ul><li>T. verrucosum </li></ul></ul>Cutaneous
    82. 83. Ectothrix invasion of hair <ul><li>Wood’s UV light </li></ul><ul><li>infected hairs fluoresce </li></ul><ul><li>bright greenish yellow under </li></ul>Cutaneous
    83. 84. Endothrix invasion of hair <ul><li>formation of arthroconidia within hair shaft </li></ul><ul><li>cuticle of hair remains intact </li></ul><ul><li>do not fluoresce under Wood’s UV light </li></ul>Cutaneous
    84. 85. Endothrix invasion of hair <ul><li>ALL AGENTS ARE ANTHROPOPHILIC </li></ul><ul><li>Trichophyton tonsurans, </li></ul><ul><li>T. violaceum </li></ul>Cutaneous
    85. 86. Culture: <ul><li>Selective media </li></ul><ul><ul><li>SDA with chloramphenicol & cycloheximide (Mycosel or Mycobiotic agar) </li></ul></ul><ul><ul><li>Dermatophyte test medium </li></ul></ul><ul><li>Non-selective medium </li></ul><ul><ul><li>Sabouraud’s dextrose agar </li></ul></ul>
    86. 87. Culture: <ul><li>Incubation </li></ul><ul><li>Room temperature </li></ul><ul><li>At least 2 weeks </li></ul>
    87. 88. Identification <ul><li>Gross color & texture </li></ul><ul><li>Microscopic characteristics </li></ul><ul><li>Confirm / compare with </li></ul><ul><ul><li>Written descriptions </li></ul></ul><ul><ul><li>Drawings </li></ul></ul><ul><ul><li>photographs </li></ul></ul>
    88. 89. Mycology
    89. 90. Microsporum canis <ul><li>Zoophilic </li></ul><ul><ul><li>cats and dogs </li></ul></ul><ul><li>Invades </li></ul><ul><ul><li>Hair </li></ul></ul><ul><ul><li>skin </li></ul></ul><ul><ul><li>rarely nails </li></ul></ul><ul><li>distribution </li></ul><ul><ul><li>worldwide </li></ul></ul>Cutaneous netti.nic.fi www.vet.ohio-state.edu
    90. 91. Microsporum canis <ul><li>lab diagnosis – culture </li></ul><ul><li>white cottony growth </li></ul>Cutaneous <ul><li>golden yellow reverse colony </li></ul>www2.provlab.ab.ca
    91. 92. Microsporum canis <ul><li>microscopic: </li></ul><ul><ul><li>spindle shaped, one end pointed, other end blunt </li></ul></ul><ul><ul><li>thick walled verrucose macroconidia </li></ul></ul><ul><ul><li>6 to 12 cells </li></ul></ul>Cutaneous www.doctorfungus.org
    92. 93. Microsporum gypseum <ul><ul><li>geophilic </li></ul></ul><ul><ul><li>usually produces a single inflammatory skin or scalp lesion </li></ul></ul><ul><li>distribution </li></ul><ul><ul><li>worldwide </li></ul></ul>Cutaneous
    93. 94. Microsporum gypseum <ul><li>lab diagnosis - culture </li></ul><ul><li>flat, spreading suede-like to granular </li></ul><ul><li>cinnamon growth </li></ul><ul><li>yellow brown pigment on reverse of colony </li></ul>Cutaneous www.ukneqasmicro.org.uk
    94. 95. Microsporum gypseum <ul><li>microscopic: </li></ul><ul><li>symmetrical ellipsoidal </li></ul><ul><li>thin walled verrucose macroconidia </li></ul><ul><li>distal end slightly rounded, proximal (point of attachment) is blunt </li></ul><ul><li>4 to 6 cells </li></ul>Cutaneous vtpb-www.cvm.tamu.edu www.medmicro.wisc.edu
    95. 96. Trichophyton mentagrophytes <ul><ul><li>zoophilic: mice, cats, horses, sheep, rabbits </li></ul></ul><ul><ul><li>inflammatory skin or scalp lesions in humans </li></ul></ul><ul><ul><li>ectothrix </li></ul></ul><ul><li>distribution </li></ul><ul><ul><li>worldwide </li></ul></ul>Cutaneous
    96. 97. Trichophyton mentagrophytes <ul><li>lab diagnosis - culture </li></ul><ul><li>flat, white to cream color; powdery to granular surface </li></ul>Cutaneous danival.org
    97. 98. Trichophyton mentagrophytes Cutaneous Microscopic <ul><li>spherical microconidia </li></ul><ul><li>forming dense clusters, “en-grappe” </li></ul>vtpb-www.cvm.tamu.edu
    98. 99. Trichophyton mentagrophytes <ul><li>spiral hyphae </li></ul>Cutaneous <ul><li>smooth thin-walled clavate multiseptate macroconidia </li></ul>Microscopic www.vet.ohio-state.edu vtpb-www.cvm.tamu.edu
    99. 100. Trichophyton mentagrophytes <ul><li>lab diagnosis </li></ul>Cutaneous www2.provlab.ab.ca <ul><li>positive urease production </li></ul><ul><li>positive for in-vitro hair perforation </li></ul>www2.provlab.ab.ca
    100. 101. Trichophyton rubrum <ul><li>anthropophilic </li></ul><ul><ul><li>chronic infections of the skin, nails, rarely scalp </li></ul></ul><ul><ul><li>ectothrix or endothrix hair infection </li></ul></ul><ul><li>distribution </li></ul><ul><ul><li>worldwide </li></ul></ul>Cutaneous
    101. 102. Trichophyton rubrum <ul><li>lab diagnosis – culture </li></ul><ul><li>white, suede-like to downy </li></ul><ul><li>wine red pigment on reverse side </li></ul>Cutaneous www.pfizer.ch www4.medfak.lu.se
    102. 103. Trichophyton rubrum <ul><li>lab diagnosis </li></ul><ul><ul><li>scanty to moderate numbers of slender clavate to pyriform microconidia </li></ul></ul><ul><ul><li>arranged “en-thyrse” </li></ul></ul>Cutaneous www2.provlab.ab.ca
    103. 104. Trichophyton concentricum Cutaneous <ul><li>Anthropophilic </li></ul><ul><li>chronic non-inflammatory tinea corporis </li></ul><ul><li>tinea imbricata – concentric scaling of skin </li></ul><ul><li>Not invade hair </li></ul>
    104. 105. Trichophyton concentricum Cutaneous <ul><li>Distribution </li></ul><ul><ul><li>Pacific Islands of Oceania </li></ul></ul><ul><ul><li>Southeast Asia </li></ul></ul><ul><ul><li>Central and South America </li></ul></ul>
    105. 106. Trichophyton concentricum Cutaneous <ul><li>Lab diagnosis </li></ul><ul><li>Slow growing deeply folded thallus </li></ul><ul><li>Cream to orange brown in color </li></ul><ul><li>Reverse buff to brown </li></ul>
    106. 107. Trichophyton concentricum Cutaneous <ul><li>Microscopic – </li></ul><ul><li>“ antler tips” hyphae, </li></ul><ul><li>chlamydoconidia </li></ul>
    107. 108. Trichophyton schoenleinii Cutaneous <ul><li>Anthropophilic </li></ul><ul><li>Cause favus </li></ul><ul><li>Chronic scarring form of tinea capitis </li></ul><ul><li>Saucer shaped crusted lesions or scutula </li></ul><ul><li>Permanent hair loss </li></ul>
    108. 109. Trichophyton schoenleinii Cutaneous <ul><li>Lab diagnosis </li></ul><ul><li>Culture </li></ul><ul><li>Waxy or glabrous </li></ul><ul><li>Deeply folded honeycomb-like thallus with sub-surface growth </li></ul>
    109. 110. Trichophyton schoenleinii Cutaneous <ul><li>Lab diagnosis </li></ul><ul><li>Microscopic </li></ul><ul><ul><li>Favic chandeliers </li></ul></ul><ul><ul><li>No macroconidia </li></ul></ul><ul><ul><li>No microconidia </li></ul></ul>
    110. 111. Epidermophyton floccosum <ul><li>anthrophophilic </li></ul><ul><li>does not invade hair in vivo </li></ul><ul><li>distribution </li></ul><ul><ul><li>worldwide </li></ul></ul>Cutaneous
    111. 112. Epidermophyton floccosum <ul><li>Culture </li></ul><ul><li>greenish-brown or “khaki” colored </li></ul><ul><li>suede-like surface </li></ul><ul><li>raised & folded center, with flat periphery </li></ul><ul><li>yellowish brown reverse pigment </li></ul>Cutaneous
    112. 113. Epidermophyton floccosum <ul><li>Microscopic </li></ul><ul><li>smooth thin-walled macroconidia often in clusters growing directly from hyphae </li></ul><ul><li>no microconidia </li></ul><ul><li>numerous chlamydoconidia </li></ul>Cutaneous botit.botany.wisc.edu www.fns.uniba.sk

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