Difference between revisions of "Subcutaneous Mycoses"

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#REDIRECT[[:Category:Subcutaneous Mycoses]]
 
 
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==Chromoblastomycosis==
 
 
 
*Occurs in horses, dogs, cats and himans
 
 
 
*Caused by [[Dermatophytosis|dematiaceous fungi]]:
 
**''Exophilia jeanselmeri, Phialophora, Cladosporium carrionii, Fonsecaea pedrosoi''
 
 
 
*Enters tissue through wounds or sites of tissue trauma
 
**Limited to subcutaneous and cutaneous tissues
 
 
 
*Causes hyperplasia and formation of verrucoid, warty nodules
 
**Warts are irregular, vegetative and pedunculated
 
 
 
*Spread is via the [[Lymphatic System - Anatomy & Physiology|lymphatic system]]
 
**Dissemination to other tissues and organs can occur
 
 
 
*Chronic condition which will progress if not treated
 
 
 
*Treatment includes [[Antifungal Drugs#The Azoles|Ketoconazole]], [[Antifungal Drugs#Flucytosine|5-fluorocytosine]] and [[Antifungal Drugs#Polyene Antifungals|amphotericin B]]
 
 
 
==Chromomycosis==
 
 
 
*Also called Phaeohyphomycosis
 
 
 
*Opportunistic
 
 
 
*Infects horses, dogs and humans
 
**Found in wounds and abrasions
 
 
 
*Caused by [[Dermatophytosis|dematiaceous fungi]]
 
**''Dactylaria gallopava, Exophiala pisciphila, E. salmonis, Scolecobasidium humicola, S. tshawytschae, Drechslera, Exophilia jeanselmeri, E. verrucosa, Fonsecaea pelrosoi''
 
 
 
*Nodular and ulcerating lesions of the skin on the feet, legs and occasionally eyes (in turkeys)
 
**Regional granulomatous lymphadenitis
 
 
 
*Single cells or clusters, spherical and thick-walled
 
*Brown pigmented fungal elements
 
 
 
*Multiply by cross-wall formation or splitting (not budding)
 
 
 
*Grows on Sabauraud's Dextrose agar ar room temperature
 
**Slow growth
 
**Takes one month
 
 
 
*For further information, see [[Dermatophytosis|dematiaceous fungi]]
 
 
 
==Epizootic Lymphangitis==
 
 
 
*''Histoplasma capsulatum'' var. ''farciminosum''
 
**Similar to ''H. capsulatum''
 
 
 
*Occurs in horses, donkeys and mules
 
*90% occurs in horses
 
 
 
*Occurs in Europe, Africa and Asia
 
**Eradicated from the UK but is still under the notifiable Diseases of Animals Act
 
 
 
*Chronic disease
 
 
 
*Highly contageous
 
**Spread by direct contact or indirect, e.g. through infected grooming equipment, [[Biting Flies|biting flies]]
 
 
 
*Once established in a population it is very difficult to eradicate
 
**Long incubation peroid
 
**New cases can develop weeks or months after the infection appears to have been eradicated
 
 
 
*Affects the [[Lymph Nodes - Anatomy & Physiology|lymph nodes]], [[Lymphatic Vessels - Anatomy & Physiology|lymph vessels]] and [[Skin - Anatomy & Physiology|skin]]
 
**Mostly of the [[Musculoskeletal System - Anatomy & Physiology#The Head and Neck|neck]] and [[Musculoskeletal System - Anatomy & Physiology#Limbs of the Domestic Species|limbs]]
 
 
 
*Causes ulcerative, nodular lesions
 
**Dissemination occurs
 
**Pulmonary disease can occur
 
**Ulcers rupture, discharging blood-stained pus for several weeks
 
 
 
*Oval or pear shaped cells
 
**Double contoured
 
**Dimorphic
 
***Grows in the yeast phase at 37°C and in the mycelial phase at room temperature
 
**Growth is slow, taking up to 8 weeks
 
**At room temperature, thick-walled chlamydospores can be seen
 
**Orgnaisms can usually be seen in swollen [[Leukocytes - WikiBlood|leucocytes]]
 
 
 
*Can be stained using Gram, Giemsa, H & E and 10% Methylene Blue followed by Carbol Fuchsin
 
 
 
*Enzyme-linked immunosorbant assay can be used to detect the fungi
 
 
 
*Life-long immunity follows recovery from infection
 
 
 
*Treatment included potassium iodide, [[Antifungal Drugs#Polyene Antifungals|hamycin]] and [[Antifungal Drugs#Polyene Antifungals|Amphotericin B]]
 
**Vaccination has also proven to be effective
 
**Injection of hyperimmune serum around skin lesions has been proven to be effective
 
 
 
==Eumycotic Mycetoma==
 
 
 
*''Pseudoallescheria boydii, Curvularia geniculata, Cochliobolus spicifer, Helminthosporium'' spp.
 
 
 
*Lives in soil
 
 
 
*Enters the body via wounds
 
 
 
*Granulomatous abscesses
 
 
 
*Microcolonies can be seen grossly in exudate or lesions
 
**Grains or granules
 
**Brown or black embedded in granulation tissue
 
**Small, irregularly shaped
 
 
 
*Infrequent infections of dogs, cats, cattle and horses
 
 
 
*Usually affect the extremities
 
**Can infect the [[Nasal cavity - Anatomy & Physiology|nasal mucosa]]
 
***E.g. Bovine nasal granuloma
 
**Can also infect the peritoneum and [[Skin - Anatomy & Physiology|skin]]
 
 
 
*Microscopically:
 
**Grains of maduromycosis with wide mycelia (compared to actinomycotic granules)
 
**Chlamydospores present
 
 
 
*Grows on Sabauraud's Dextrose agar
 
**Slow
 
**Takes 2-3 weeks
 
 
 
*Treatment includes [[Antifungal Drugs#The Azoles|Ketoconazole]], [[Antifungal Drugs#Flucytosine|5-fluorocytosine]] and [[Antifungal Drugs#Polyene Antifungals|amphotericin B]]
 
 
 
==Hyphomycosis==
 
 
 
*''Hyphomyces destruens''
 
 
 
*Opportunistic infection
 
**Associated with trauma
 
 
 
*Rare
 
 
 
*Caused by ''Penicillium, Beauveria, Acremonium, Fusarium, Paecilomyces''
 
 
 
*Infects both animals and humans
 
**Mainly affects horses
 
 
 
*Tropical and semi-tropical countries
 
 
 
*Progressive disease causing granulating and ulcerating lesions on the legs and lower body
 
**Lesions grow rapidly
 
**Cause extreme debility
 
 
 
*Occurs in water
 
**Most often seen in ponies with access to ponds
 
 
 
*Chemotactically attracted to horse hair
 
 
 
*Does not respond well to treatment
 
**Radical surgical excision the best method
 
**Experiemental vaccination treatment is currently underway and has shown promising results
 
 
 
==Pythiosis==
 
 
 
*Causes Mycotic Swamp Fever
 
 
 
*Also called phycomycosis
 
 
 
*Occurs in the USA, Australia, New Guinea, India, Brazil, Colombia, Japan, Costa Rica and Indonesia
 
 
 
*''Pythium insidiosum''
 
 
 
*Enters via wounds
 
**[[Lips - Anatomy & Physiology|Lips]], [[Musculoskeletal System - Anatomy & Physiology#The Head and Neck|head]], [[Musculoskeletal System - Anatomy & Physiology#The Head and Neck|neck]], fetlock, hock and [[Hoof - Anatomy & Physiology|hoof]]
 
 
 
*Granulomatous infection
 
**Necrosis and fistulous tracts
 
**Yellow lesions
 
 
 
*Branching, separated fungi
 
 
 
*Progressive (rather than systemic) disease
 
 
 
*Surgery is needed
 
 
 
==Rhinosporidiosis==
 
 
 
*''Rhinosporidium seeberi''
 
 
 
*Lives in water
 
 
 
*Causes a chronic, benign disease
 
 
 
*Affects cattle, mules, horses, dogs and humans
 
 
 
*Causes polyps on the [[Nasal cavity - Anatomy & Physiology|nasal]] and [[Eye - Anatomy & Physiology|ocular]] mucous membranes
 
**Over 90% of cases affecting the [[Nasal cavity - Anatomy & Physiology|nasal]] mucous membranes affects male animals
 
 
 
*Occurs most frequently in tropical countries
 
**Also common in the USA
 
 
 
*Large sporangia can be seen on wet mounts
 
**Endospores visible
 
**Sporangia develop into small, globose spores
 
 
 
*Treatment is by surgical excision
 
 
 
==Sporotrichosis==
 
[[Image:Sporotrichosis horse.jpg|thumb|right|150px|Sporotrichosis in a horse -Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath]]
 
[[Image:Sporotrichosis cigar cells.jpg|thumb|right|150px|Sporotrichosis cigar shaped cells -Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath]]
 
*''Sporothrix schenckii''
 
 
 
*Occurs in soil, wood and vegetation
 
**Saprophyte of both decaying and healthy vegetation
 
 
 
*Worldwide
 
 
 
*Exogenous infections through wounds
 
 
 
*Sporadic infections
 
 
 
*Non-contageous
 
 
 
*Causes subcutaneous nodules or granulomas
 
**Nodules ulcerate discharging pus
 
 
 
*Spread via the [[Lymphatic System - Anatomy & Physiology|lymphatics]]
 
 
 
*The [[Bones and Cartilage - Anatomy & Physiology|bones]] and viscera can be involved which terminates in mortality
 
**This is rare
 
**Reported in dogs and horses
 
 
 
*Affects dogs, horses, cats, monkeys, mules, camels, donkeys, cattle, fowl and rodents
 
**Most commonly seen in horses as an ascending lymphocutaneous infection of the legs
 
**Can be confused with [[Subcutaneous Mycoses#Epizootic Lymphangitis|epizootic lymphangitis]] in horses
 
 
 
*Single cell, cigar shaped
 
**Usually found within [[Neutrophils - WikiBlood|neutrophils]]
 
**Yeast cell clusters with peripheral eosinophilic rays can be seen in tissue sections
 
 
 
*Stained using PAS, Gram stain (positive), fluorescent antibody and Calcofluor White
 
 
 
*Latex agglutination and immunodiffusion serology can be performed
 
 
 
*Grows on Blood agar and Sabouraud's Dextrose agar in one to three weeks
 
**At 37°C:
 
***Colonies are smooth, cream to tan coloured and soft
 
***No mycelium can be seen
 
**At 25°C to 27°C:
 
***Colonies turn from white and soft to tan to brown to black
 
***Leathery, wrinkled and coarse
 
***Mycelium can be seen as branching septate hyphae
 
***Conidiospores can also be seen
 
 
 
*Potassium iodide treatment orally
 
**[[Antifungal Drugs#Flucytosine|5-fluorocytosine]] and [[Antifungal Drugs#Polyene Antifungals|amphotericin B]] can also be used
 
 
 
==Further Links==
 
*Pathology of [[Mycotic skin infections - Pathology#Subcutaneous mycoses|subcutaneous mycoses]]
 
 
 
*[[Antifungal Drugs]]
 

Latest revision as of 13:38, 29 April 2010