Mycetoma And Subcutaneous Infections Flashcards
What is myetoma?
Chronic subcutaneous infection, usually localised but may have deeper extension to bone and joints
How is mycetoma spread?
Soil transmitted: no human to human transmission
Where is the global burden of mycetoma?
Sudan, Mexico and India
What can mycetoma be split down into?
Actinomycetomas- nocardia and strep
Eumycetomas (fungal mycteomas)
Where is it dristibuted?
Mainly lower extremeties
Foot, but also shoulder
What is eumycetoma?
Fungal infection
Frows slowls, less aggressive with fewer Fistula compared to actinomycetoma
Predominantly in tropical countries and in males
Superinfections very common
What is the main fungal mycetoma? What is the main clinical sign?
Madurella mycetomatis
Black grains are the key sign
How do you diagnose eumycetoma?
Need to do fine needle aspiration
If not, biopsy
Wash drain, use KOH preparation
Tx of Eumycetoma?
Less responsive to medical treatment
Need itraconazole or voriconazole
Surgery only has a role in early disease
What is actinomycetoma?
This is a bacterial mycetoma
Aerobic pathogens
Typically caused by nocardia, streptomyces (white/yellow grains) and actinomadura (red or orange grain)
Nocardia Braziliensis predominates in America
Streptomyces Somaliensis
How do you diagnose actinomycetoma?
Culture using blood agar medium
DST is highly recommended
Tx of Actinomycetoma?
Combine antimicrobials: Trimethoprim + aminoglycoside or rifampicin or dapsone
Continue for 6 -24 months
Surgery does not have a role
Eumycetoma vs Actinomycetoma?
Eumycetoma:
typical from Africa and India
Typically feet, few Fistulas
Bigger grains
Needs medical and surgical tx
Actinomycetoma:
Typically Latin america
40-50 yrs
Limbs and chest
Grains white/yellowish and smaller
Much more aggressive with multiple fistulas
Medical tx only
What is botryomycosis?
Chronic, bacterial infection
Sinus tracts with grain discharge that is white or yellow
Male predominance
Cutaneous and visceral presentations
Staphylococcus Aureus most common
What is clinical presentation of botryomycosis?
Follows traumatic inoculation
Feet, hands and neck affected
Yellow/white grain discharge
Extends to subcutaneous structures
What is visceral botryomycosis?
Endogenous spread to organs
Need to do FNA to isolate bacteria
What are the different grains under microscope?
Hyphae structure - eumycetoma
Filamentous bacteria -actinomycetoma
Bacteria cocci and rods- botryomycosis
What is chromoblastomycosis?
STD
Usually involves trauma with wood or vegetation
80% agricultural workers
Male predominance
What agents are most commonly involved?
Fonsecaea Pedrosi
What is the clinical presentation of botryomycosis?
Chronic, slow growing
nodular, verrucous (cauliflower like)
Tumoral
Plaque and mixd form
Always has black dots on the surface which will show fungi
Pathological finding of chromoblastomycosis?
See sclerotic or fumagoid bodies
Double walled brown structures
How do you treat chromoblasto?
Need cryotherapy or thermotherapy
Where do you find lobomycosis? What is the agent?
Amazon basin and Central America
Agent is Lacazia Loboi
How does lobo present?
Often history of trauma with snake or insect
Usually a painless, localised nodular lesion
Outer legs and ears are typical places
How do you Dx lobo? Tx?
Need KOH stain, round structures in a chain
Posaconazole
What is Phaeohyphomycosis?
caused by dark cell moulds
Usually in immunocompromised hosts
What is entomophthoramycosis?
Basidobolus spp and conidiobolus spp, normal soil inhabitants
What is conidiobolus?
Nasal nodule which leads to obstruction, thickening of the skin and extension to face
Non seated hyphae
Need itraconazole
What is basidiobolus?
Basidiobolus ranarum
Nodular Lesions on chest, trunk, arms and buttocks
