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Similar to Sporotrichosis & chromoblatomycosis
Sporotrichosis & chromoblatomycosis
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- 2. o Deep fungalinfections comprise two distinct groups of conditions,the subcutaneous & systemic mycoses o Neither are common,the subcutaneous mycoses,with some exceptions ae largely confined to the tropics & subtropics o Systemic mycoses common among immunocomprised patients AIDS & receiving treatment for malignancies
- 3. o Systemic mycosesmay also affect healthy individuals in the form of primary respiratorry infections such as histoplasmosis & coccidioidomycosis o These fungi are usually dimorphic or exist in a different morphologic phase(yeast or mold)
- 5. Subcutaneous mycoses: o Sporotrichosis oMycetoma o Chromoblastomycosis o Phaeohyphomycosis o Lobomycosis o Rhinosporidiosis o Subcutaneous zygomycosis
- 6. Systemic mycoses o Histoplasmosis oBlastomycosis o Coccidioidomycosis o Paracoccidioidomycosis o Infections caused by Penicillium marneffei o Cryptococcosis o Systemic candidosis o Zygomycosis o Cutaneous infection caused by Pneumocystis jiroveci o Infections caused by Pythium insidiosum o Protothecosis
- 7. Subcutaneous mycoses: mycosesof implantation o are sporadically occurring infections caused by fungi present in the natural environment, which are directly inoculated into the dermis or subcutaneous tissue through a penetrating injury o As many have long incubation periods, they may be seen in countries outside the endemic areas in patients who were originally infected elsewhere
- 8. o The mostcommon of these infections are sporotrichosis, mycetoma & chromoblastomycosis. o phaeohyphomycosis, lobomycosis, rhinosporidiosis and subcutaneous zygomycosis are rare
- 9. o rose-pickers disease oAn acute or chronic fungal infection caused by Sporothrix schenckii. o There are both cutaneous and systemic forms of sporotrichosis. o Sporothrix schenckii is a dimorphic fungus. It occurs in both temperate and tropical zones Sporotrichosis
- 10. o Slender (2-μm)hyphae bear small, oval to pyriform, hyaline conidia produced along the sides of the hyphae and sympodially at the ends of delicate conidiophores arising at right angles from the hyphae. o The arrangement of the conidia at the apex of the conidiogenous cell is often described as palmate or flower-like, with each conidium attached by a denticle to the small vesicle
- 12. • The incidenceis highest in the autumn and first half of the winter (high humidity and temperatures between 16 and 22°C) . • These conditions favour saprophytic growth of S. schenckii. • Sporotrichosis is rare in semiarid areas. The fungus grows on decaying vegetable matter, for example the timber in mines
- 13. • It hasbeen shown that the timber harbours the fungus before being taken underground, and that the source is probably the soil in the vicinity of the mines. • S. schenckii could be recovered from the feet of mine workers who did not have sporotrichosis. • also occur in other groups occupationally exposed to the organism, such as workers using straw as packing material, forestry workers,florists or gardeners.
- 14. • In mostcases of cutaneous sporotrichosis, the portal of entry into skin or mucous membrane by trauma, as in a minor puncture wound caused by a thorn or to a splinter, or perhaps an insect bite. • Sporotrichosis is not contagious, although transmission has been recorded from cats.
- 15. • Adult malesare, by their occupation, most exposed to the risk of infection. • Systemic sporotrichosis is rare, and the portal of entry is thought to be the lung in these cases.
- 16. • Clinical features: •The main clinical varieties of sporotrichosis are the cutaneous and the systemic forms. • In turn cutaneous sporotrichosis is normally divided into two main types, the lymphangitic and fixed forms. • occasionally atypical varieties such as mycetoma- like or cellulitic forms may occur
- 17. • Lymphangitic: • Themost common type of sporotrichosis is the localized lymphatic variety, which follows the implantation of spores in a wound. • usually occurs on exposed skin, often on the upper extremity, and is known as lymphangitic sporotrichosis. • A nodule or pustule forms, which may break down into a small ulcer
- 18. • Untreated thedisease usually follows a chronic course, which is characterized by involvement of lymphatics from the draining area, a chain of lymphatic nodules develops. • New nodules appear at intervals of a few days. These soften and ulcerate, and are connected by tender lymphatic cords. • A thin purulent discharge may come from the primary lesion and the earliest lymphatic nodules.
- 19. • As thedisease becomes chronic, the regional lymph nodes become swollen and may break down. The primary lesion may heal spontaneously leaving the lymphatic nodes enlarged
- 22. • Fixed type: •where the pathogen remains more or less localized at the point of inoculation, is less common. • The lesions may be acneiform, nodular, ulcerated or verrucous; the latter form is occasionally very extensive. • Less commonly, there may be infiltrated plaques or red scaly patches. An ulcer may be gummatous or may simulate an epithelioma.
- 24. o The plaquesmay suggest leishmaniasis or tuberculosis. o It is thought that this variety may reflect a high degree of immunity on the part of the patient. o The variable morphology of this type is notable
- 25. o The lesscommon systemic form probably follows inhalation, and presents either with local pulmonary disease or focal or widely disseminated lesions in the joints, meninges and skin. o There is some evidence that systemic sporotrichosis occurs in patients with some defect in host defence, such as alcoholics. o Where sporotrichosis has been reported in AIDS patients, the lesions have usually been widespread and have affected internal organs as well as the skin.
- 26. o contrast tothe cutaneous variety, which occurs in perfectly healthy individuals. o Sporotrichosis in AIDS patients, the lesions have usually been widespread and have affected internal organs as well as the skin. o In the systemic type, which is rare, ulcerated nodules may develop anywhere on the body or mucous membranes, and visceral lesions may occur o If untreated, this type is fatal but systemic sporotrichosis is exceedingly rare
- 27. Lab diagnosis: • S.schenckii is very rarely present in quantity in infected tissues, and direct microscopy of clinical material is of little or no value in confirming a diagnosis. • Fluorescent antibody techniques have been successfully employed in locating the pathogenic phase in vivo. • The fungus grows readily on common agar media.
- 28. Cigar bodies representthe elongated yeast like form of the fungus and when these yeast forms are surrounded by eosinophilic hyaline ray like processes they are referred to as ‘sporothrix asteroid’,usually seen in the centre of suppurative granulomas
- 29. • The coloniesare leathery, moist and initially white or cream with a wrinkled surface. • As the colonies age, they may become progressively darker until they are brown or black
- 30. Physiological tests: • Toconfirm the identification, it is essential to convert this thermally dimorphic fungus to the yeast phase, as fungi that are non-pathogenic and morphologically very similar may be isolated as contaminants. • This is best achieved on brain–heart infusion agar supplemented with sheep’s blood and incubated at 37°C. The yeasts are typically oval or cigar-shaped
- 31. Treatment: • Localised lymphangitic: •Potassium iodide in large oral doses is effective in the localized types, and should be continued for 3– 4 weeks after clinical cure. • It is cheap and effective, although side effects are common.(hypersalivation & nausea) • A recommended schedule is five drops initially, increasing to 4–6 mL of saturated potassium iodide three times daily.
- 32. • If unresponsive,Itraconazole 100–200 mg/day or terbinafine 250 mg/day are both effective and well tolerated or iv amphotericin B Systemic form: • Itraconazole 100–200 mg/day or terbinafine 250 mg/day • intravenous amphotericin B may also be helpful
- 33. • In allcases treatment is continued for at least 1 week after clinical resolution • the local application of heat may produce recovery in some patients.
- 34. Differential diagnosis: • Mycobaterialinfections • Leishmaniasis • Mycobacterium marinum infection (fish-tank granuloma) may closely resemble lymphangitic sporotrichosis • Primary cutaneous nocardia infections
- 35. Chromoblastomycosis • Chromomycosis • Verrucousdermatitis • A chronic fungal infection of the skin and subcutaneous tissues caused by pigmented fungi, which produce thickwalled single or multicelled clusters (sclerotic or muriform bodies) in tissue • characterized by the production of slowgrowing exophytic lesions, usually on the feet and legs
- 36. • Chromoblastomycosis iscaused by several fungi, the most common : Phialophora verrucosa Fonsecaea pedrosoi F. compacta Cladophialophora carrionii Rare causes Rhinocladiella aquaspersa The causative fungi have been isolated from wood & soil, and the infection usually results from trauma, such as a puncture from a splinter of wood. The condition is usually found in rural communities
- 37. • All thesefungi are named according to the dominant form of conidiation • Phialophora verrucosa • Microscopy: dominant form of conidiation is the production of flask-shaped phialides with a pronounced dark collarette at the apex. These are produced laterally or terminally • hyaline thin-walled elliptical conidia are produced at the tip of the phialide in basipetal succession
- 38. • Fonsecaea pedrosoi •Microscopy: dominant form of conidiation is sympodial with the conidia confined to the upper part of the cell. • The brown single-celled conidia are produced on short denticles and may in turn produce secondary conidia in a similar manner. • Conidia produced by acropetal budding
- 39. Clinical features: • Thelesions are usually found on exposed sites particularly the feet, legs, arms, face and neck. • A warty papule slowly enlarges to form a hypertrophic plaque. • In some lesions, the plaque is flat and expands slowly with central scarring. • The early lesion may occasionally be an ulcer. Eventually, after months or many years, large hyperkeratotic masses are formed, and these may be as large as 3 cm thick.
- 40. • Secondary ulcerationmay occur • The lesion is usually painless unless the presence of secondary infection causes itching and pain. • Satellite lesions are produced by scratching, and there may be lymphatic spread to adjacent areas.
- 41. • Haematogenous spreadhas occurred but is rare, and brain abscesses have been described. • Secondary infection may eventually lead after several years to lymphatic stasis with the production of elephantiasis. • Some forms of the infection produce psoriasiform lesions. Squamous carcinomas may develop in chronic lesions
- 45. • Lab diagnosis: •Irrespective of species, the pathogen can be seen in biopsy sections as deeply pigmented, thick-walled muriform or sclerotic cells. • Occasionally, in superficial skin scrapings from the surface of the lesions, pigmented hyphae rather than sclerotic cells are seen. • Multiplication in vivo is by fission rather than budding, and this results in the production of single, two- or multiple-celled clusters.
- 46. H&E stained sectionshowing characteristic dark brown sclerotic cells which divide by binary fission and not by budding. Note all agents of chromoblastomycosis form these sclerotic bodies in tissue.
- 47. Culture: • colonies ofall species are dark grey–green to black and velvety or downy, with a black reverse. • Three forms of conidial production are observed in the most common agents of infection: acropetal budding production of phialides sympodial conidiation
- 48. Treatment: • Itraconazole (100–200mg daily) or terbinafine (250 mg daily) is often successful, although responses to both are thought to be better if the causative organism is C. carrionii . • Flucytosine used on its own or combined with amphotericin B may also be effective, but resistance to flucytosine may develop if used alone
- 49. • Other approachesto treatment: cryotherapy or the local application of heat • The use of surgery is contentious; in larger plaques there is a risk in pursuing this approach as satellite lesions may develop around the excision site • Surgery is really only indicated in very small lesions combined with chemotherapy.
- 50. Differential diagnosis: blastomycosis (bythe absence of a sharp border containing minute abscesses and also the absence of pulmonary lesions ) cutaneous tuberculosis leishmaniasis syphilis yaws
- 51.