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| | Image:Microsporum equinum.jpg|<center><p>'''Microsporum equinum'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center></gallery> | | Image:Microsporum equinum.jpg|<center><p>'''Microsporum equinum'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center></gallery> |
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| | + | [[Image: Microsporum canis lesions.jpg|100px|thumb|right|<small><center>''Microsporum canis'' alopecia and scaling lesions (Courtesy of Bristol BioMed Image Archive)</center></small>]] |
| | + | [[Image: Ringworm dog.jpg|100px|thumb|right|<small><center>Ringworm in a dog (Courtesy of Bristol BioMed Image Archive)</center></small>]] |
| | + | [[Image: Trichophyton mentagrophytes dog.jpg|100px|thumb|right|<small><center>Trichophyton mentagrophytes in a dog (Courtesy of Bristol BioMed Image Archive)</center></small>]] |
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| | + | *Caused by [[Fungi|dermatophytes]] |
| | + | **''Microsporum'' - zoophilic |
| | + | **''Trichophyton'' - geophilic |
| | + | **''Epidermophyton'' - anthropophilic |
| | + | *Common in many species, especially cats |
| | + | *Hot, humid environment predisposes and viable fungi peripherally |
| | + | *More common in young animals |
| | + | *Produce proteolytic enzymes to penetrate surface lipid |
| | + | *Fungal hyphae invade keratin -> break into arthrospores |
| | + | *Epidermal hyperplasia ([[Skin Glossary - Pathology|hyperkeratosis, parakeratosis, acanthosis]]) and inflammation |
| | + | *Superficial perivascular dermatitis -> exocytosis (migration through epidermal layers) -> intracorneal microabscesses |
| | + | *Exocytosis -> folliculitis -> furunculosis |
| | + | *Highly variable lesions |
| | + | *Normal -> eruptive nodular -> pseudomycetoma -> onychomycosis |
| | + | *Grossly: |
| | + | **Circular or irregular lesion, may coalesce |
| | + | **Scaly to crusty patches |
| | + | **Alopecia due to broken hair shafts and hairs lost from inflammed follicles |
| | + | **Follicular papules and pustules |
| | + | **Peripheral red ring ('''ringworm''') due to dead fungi in areas of inflammation at centre of lesions and viable fungi peripherally |
| | + | *Microscopically: |
| | + | **Perifolliculitis, folliculitis or furunculosis |
| | + | **Epidermal hyperplasia |
| | + | **Intracorneal microabscesses |
| | + | **Septate hyphae or spores may be found in stratum corneum and keratin of hair follicles |
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| | [[Category:Fungi]] | | [[Category:Fungi]] |
| | [[Category:To_Do_-_Fungi]] | | [[Category:To_Do_-_Fungi]] |