Flashcards in Infection And Immunology David Taylor Deck (56)
What are fungi? What are they divided into?
Eukaryotic organisms so they have a true nuclei
Divided into yeasts and moulds
Fungi are carbon heterotrophs. What does this mean?
They require preformed organism compounds as carbon sources
What are dermatophytes?
Keratinophilic: associated with infections of the skin nails and hair and get spread through direct contact.
Common symptoms include itching burning and pain
What is common in the name of dermatophytes??
Eg tinea corporis
What is tinea corporis?
Ringworm of the skin
What is tinea cruris?
Ringworm of the groin
What is tinea capitis?
Ringworm of the scalp
Dermatophytes are usually diagnosed visually or by sending nail clippings off for analysis.
What does ring worm look like?
Raised around the edges with a clear area in middle
What is first line treatment for tinea corporis and tinea cruris?
Eg clotrimazole, ketoconazole
Should treat with creams for a further two weeks to ensure it goes away
If topical treatment fails, or if someone's immuno compromised or the infection is particularly wide spread, what can we use to treat tinea corporis and cruris?
250mg a day for 4 weeks
What do we use to treat tinea Capitis? (Ringworm of scalp)
Usually oral treatment is required such as Terbanifine or griseofulvin, PLUS:
Ketoconazole/ selenium sulphide shampoos or terbanafine creams twice weekly
What organisms is griseofulvin effective against?
What about terbinafine?
Griseofulvin effective against Trichophyton tonsurans, microsporum spp.
Terbinafine effective against Trichophyton tonsurans
Griseofulvin is only effective against dermatophytes. Why are long courses needed? Who should avoid it?
Long course as it does not persist in keratinous tissue after the end of therapy
Shouldn't be taken by people with severe liver disease, and systemic lupus erythematosus
Should be avoided in breast feeding
Avoid in pregnancy and for one month after stopping treatment
What are the main side effects of griseofulvin?
GI side effects
Griseofulvin has many interactions. What are these?
Enhances effects of alcohol
Decreases efficacy of oral contraceptives and coumarins
Needs to be taken with or after fatty foods!
What is used first line to treat athletes foot?
For 2-4 weeks or
Terbinafine cream for 1 week
Undecenoates for 2-4 weeks
If topical treatment fails for severe athletes foot, what three oral tablets could be taken? (Just say names)
Terbinafine can be taken orally or topically. It concentrates in keratinous tissue. When should it be avoided? What are the side effects?
Avoid In pregnancy and liver disease.
Hepatotoxicity with prolonged therapy
Serious skin reactions
What species can we commonly find infecting our nails?
Onychomycosis means nails. What's the most common type of nail infection?
DLSO starts at the top of the nail works down to nail bed
What's a good treatment for fungal nails?
Itraconazole pulse therapy
Itraconazole stays in keratin in nails for longer
Can also use itraconazole 200mg daily for 3 months
Could also use terbinafine for 6 weeks to 3 months
Note this is all SYSTEMIC management, taken orally
We can also use topical treatment for nail infections eg Ticonazole, Amorolfine. When is this appropriate to use?
Topical treatment will only work in mild distal disease in up to 2 nails. White superficial and early DLSO.
Localised distal nail may respond to Ticonazole or amorolfine
What is pityriasis versicolor?
Colonisation of the stratum corneam (in skin)
Caused by malassezia furfur
Starts at the neck and shoulders, multiple dark patches
Starts around puberty
What can we treat pityriasis versicolor with?
Clotrimazole or ketoconazole creams
If these fail
Relapse is COMMON
Why is oral ketoconazole not really used anymore?
Can cause serious and rapid hepatotoxicity
Should only be given under specialist advice
Monitor liver function before and 2-4 weeks after treatment then monthly.
What topical therapy can we give for oropharyngeal candida?
First line: Imidazole antifungals eg miconzaole oral gel for 7 days
Second line: Polyene antifungals such as nystatin suspension 7 days
What oral therapies can be given for oropharyngeal candida?
50mg daily for 7-14 days
Give it for 14 days if atrophic candidiasis associated with dentures
What fungal organism accounts for 90% of vaginal candidiasis?
What topical treatments are effective for uncomplicated Vuvovaginal candidiasis?