Fungi and Infestations Flashcards
what is another word for tinea infection
ringworm
what is seen in a characteristic tinea infection
erythematous scaly lesion with a leading edge and a ‘spared’ center
how is tinea classified
by body location
where is tinea pedis found
foot
where is tinea manuum found
wrist/hand
where is tinea cruris found
groin
where is tinea corpis found
all over the body
where is tinea captis found
on the top of the head
what population is tinea captis more common in
afrocaribbean
what is onychomycosis
tinea of nails, extremely common causing onycholysis, hyperkeratosis and discoloration - often confused for psoriasis
how do you investigate tinea infection
scrapings from the leading edge of the infection
or if on nails clippings are sent
certain fungi flouresce under UV (woods) light
if hair - hair samples + root is best
what are some differentials for tinea infection
psoriasis
discoid eczema
erythasma
candidisasis
how do you differentiate candidiasis from tinea
candidiasis has satellite lesions and pustules
what are the high risk groups for candidiasis infection
young
very old
immunocompromised
diabetics
what’s the treatment for candidiasis infection
systemic = Polyenes (Nyastatin/Amphotericin B) localised = clotrimazoles or oral fluconazole
what treatment is usually recommended for nail infections
topical treatment - Azole (a triazole like itraconazole) or Terbinafine
Systemic treatment - terbinafine/itraconazole
whats the treatment lengths for terbinafine for skin, fingernail and toenail infections
skin 250mg 2-4 weeks
fingernail - 250mg 3 months
toenail - 250mg 3-6 months
why are imidazoles generally avoided for systemic therapy
they cause inhibition of androgen synthesis leading to gynaecomastia
what type of azole is the systemic therapy of choice
Triazoles
why is griseofulvin less popular now
it is fungistatic not fungicidal
who gets given griseofulvin
children under 12 with tinea
what is malassezia furfur
a type of fungi that manifests in either Pitryiasis versicolour or seborrheic dermatitis
what is Pitryiasis versicolour
finely scaled yellow/brown macules commonly on trunk - may be hyperpigmented/hypopigmented depending on skin type
what is the treatment for Pitryiasis versicolour
topical antifungal 7/7 (or itraconazole if immunosuppressed)
what is seborrhoeic dermatitis
mild form of dermatitis that commonly affects brow, paranasal areas and perioral areas
known as cradle cap in infants
how do you treat seborrheic dermatitis
topical azoles
low potency steroids for rapid short term treatment (doesnt work long term)
Sometimes topical immunomodulators such as tacrolimus and pimecrolimus are used off license, especially when withdrawing from long term steroids
what causes scabies
sarcoptes scabiei mite
how does scabies spread
human to human contact
what is a clinical feature of scabies
itchy spot that becomes excoriated
scratch-like burrow spot
if untreated more burrows
what sites are most common for scabies
axilae finger webs flexures breasts insteps ankles
what is norweigan/crusted scabies and who gets it
severe form of scabies, elderly or immunocompromised
what causes the excoriation in scabies
pruitis from the mite faeces
whats the treatment for scabies
12 hour application for permetrin/malathion repeated after a week (lifecycle of mite - treatment doesnt kill eggs)
avoid close contact and wash linens/clothes
what is the most common complication post-treatment of scabies
eczema development after the mites have gone
whats the treatment for headlice
fine tooth combing daily + use of suitable conditioner
pediculocides (malathion, permethrin,carbaryl)
regular checking
