onychomycosis Flashcards
Treatment of onychomycosis indications:
- hx of lower extremity cellulitis with ipsilateral toenail onychomycosis,
- diabetic with toenail onychomycosis
- risk factors for cellulitis (prior cellulitis, venous insufficiency, and edema)
- for cosmetic reasons.
Treatment of onychomycosis
daily oral terbinafine - 1st line
fingernail 6 weeks
toenail 12 weeks
itraconazole bid x 1 week/month for 2 months (toenail)
diagnosis of onychomycosis
yellowish discoloration of toenails and hyphae on KOH smear make onychomycosis most likely diagnosis.
Nail dystrophy can look similar to psoriasis of the nails.
so need to culture the nail material which can take up to 6 weeks.
how good is the treatment effectiveness of onychomycosis
not very good… ineffective with 20-50% recurrence rate
it’s expensive too.
12 week course has best chance of successful treatment (40-60%) and fewer drug drug interactions.
If treating with terbinafine what do you need to check?
check LFTs prior to treatment and after.
does griseofulvin and fluconazole help treat toe fungus
no it’s less effective compared to terbinafine or itraconazole
pulse therapy for treatment of toe nail fungus
one week of twice daily itraconazole per month for two months
Second line treatment but can be used as alternative for those who are not drug compliant or prefer this method.
what causes onychomycosis?
variety of fungi, yeast, dermatophytes and other molds
typical findings of onychomycosis:
nail discoloration (white, yellow, brown) and dystrophic changes (thickening, splitting, fracturing of nail, and occasionally underlying injury to nail bed.
if someone has a dystrophic nail (split, thickened nail) do they have onycomycosis?
no only 50-60% of pts with dystrophic nails have onychomycosis.
other causes could be psoriasis, eczema, lichen planus
Because there are other causes of onycomycosis for a dystrophic nail, what should be done?
get a potassium hydroxide (KOH) preparation of nail scrapings
it’s simple and inexpensive.
fungal culture can also be done of hte nail clippings.
if we must do empiric treatment of toenail fungus, what do we use?
oral terbinafine (for toenail onychomycosis with diagnostic testing who fail treatment).
when do we use topical antifungal therapy for onychomycosis treatment?
efinconazole (less severe cases (limited to distal nail plate and only after diagnostic confirmation)
what is acute paronychia?
this is swelling, erythema and pain in the nail folds and surrounding skin. Treat with topical antibiotics and antiseptic soaks.
what do you do for chronic paronychia (swelling and erythema around nailfold beds with dystrophic changes of nail plate?
topical steroids
ungual psoriasis (with nail ptting and onycholysis) also can get topical steroids.
