Fungal infections Flashcards
What are fungi?
Eukaryotic organisms with a true nuclei
What are the two types of fungi?
Yeasts and moulds
What are yeasts?
unicellular, round or oval cells which reproduce by budding or fission
What are moulds?
multi-cellular also called filamentous fungi, produce hyphae
What are dermatophytes?
Moulds
What are dermatophytes associated with?
infections of skin, nail and hair
What common symptoms do dermatophytes cause?
itching, burning, pain and irritation
What is tinea corporis?
Ringworm of the skin
What is tinea cruris?
Ringworm of the groin
What is tinea capitis?
Ringworm of the scalp
What is first line treatment for tinea corporis and cruris?
Topical imidazole:
clotrimazole or miconazole
Terbinafine is an alternative
What oral therapy can be used for ringworm if needed?
Terbinafine 250mg OD
Itraconazole 100mg OD
Griseofulvin rarely given
What is the treatment for Tinea Capitis?
Ketoconazole, selenium sulphide shampoos or terbinafine cream twice weekly for 2 weeks.
Oral:
Griseofulvin 1g OD
Terbinafine 250mg OD for up to 4 weeks
What is Griseofulvin active against?
Microsporidium
What is Terbinafine effective against?
Trichophyton tonsurans
What is Griseofulvin only active against?
Dermatophytes
Does Giseofulvin persist in keratinous tissue after end of therapy?
No
What is griseofulvin contraindicated in?
Patients with severe liver disease & SLE
Can griseofulvin be used if breastfeeding?
No
How long should women avoid pregnancy for after taking griseofulvin?
one month
How long should men not father a child for after taking griseofulvin?
6 months
What are the main side effects of griseofulvin?
GI & headache, cognitive
What does griseofulvin interact with?
oral contraceptives
coumarins
possibly cyclosporin
What should griseofulvin be taken with or after?
Fatty food
What is Tinea pedis?
Athlete’s foot
What species can cause athletes foot?
Trichophyton rubrum
Trichophyton mentagrophytes
Epidermophyton floccosum
What is first line treatment for athlete’s foot?
Imidazole cream 2-4 week
Terbinafine cream 1 week
What is the oral treatment for athlete’s foot?
Terbinafine 250mg OD 2-6 weeks
Itraconazole 100mg OD for 30 days or 200mg BD for 7 days
Griseofulvin 500mg OD in divided doses for 4-8 weeks
Does terbinafine concentrate in keratinous tissue?
Yes
What should terbinafine be avoided in?
Pregnancy
Liver disease
Renal impairment
What are the side effects of terbinafine?
GI disturbances
Hepatotoxicity
Serious skin reations
What interacts with terbinafine?
Rifampicin
OCP
What species comonly cause onchomycosis?
Trichophyton rubrum
Epidermophyton floccosum
Trichophyton mentagrophytes
Candida
What is 1st line treatment for onchmycosis?
Terbinafine 250mg OD for 6 weeks to 3 months for finger nails (3-6 months for toe)
Itraconazole 200mg BD for 7 days subsequent courses at 21 day intervals. 2 pulses for giners, 3 pulses for toes
What is the topical treatment for onchomycosis?
Amorolfine once or twice weekly. 6 months nails, 9-12 months toe nails
What is pityriasis versicolor?
Colonisation of the stratum corneum by Malassezia
Where is pityriasis versicolor usually found?
patches on the trunk, neck and shoulders
What is the topical treatment for pityriasis versicolor?
Ketoconazole shampoo
Selenium sulphide shampoo
Clotrimazole, econazole, ketoconazole or miconazole creams
What is the systemic treatment for pityriasis versicolor?
Itraconazole 200mg OD 7 days
Fluconazole 50mg OD for 2 to 4 weeks
What is the topical treatment of Oropharyngeal candidia ?
Miconazole oral gel 7 days
Nystatin suspension 7 days
What is the oral treatment for Oropharyngeal candidia ?
Fluconazole 50mg OD for 7-14 days
What are the risk factors for cutaneous candidiasis?
Systemic antibiotics, HIV, skin conditions, skin maceration
How does cutaneous candidiasis present?
Prutitus and irritation, burning and pain
What is the oral treatment for cutaneous candidiasis?
Fluconazole 50mg OD 2-4 weeks
