Tinea Flashcards
What are the different types of tinea?
capitis (ringworm of the scalp)
corporis (ringworm)
cruris (jock itch)
pedis (athletes foot)
finger/toenail (onychomycosis)
versicolor
What are some differences between tinea versicolor and vitiligo?
tinea versicolor:
-fungal infection causing skin discoloration
-overgrowth of yeast triggered by hot, humid climate
-treated by topical and oral antifungals
vitiligo:
-disease causing loss of skin color
-caused by autoimmune disorder, defective melanocytes,
oxidative stress, toxic chemicals, nerve damage
-treated by steroids or UV
Is tinea capitis treatable through OTC products?
no (minor role, if any) this is medical care
the scalp is hard to penetrate, there is nothing OTC that can penetrate the scalp
True or false: tinea capitis is caused by a ringworm
false
fungal infection
Describe tinea capitis.
affects your scalp and hair shafts
causes small patches of itchy, scaly skin
highly contagious (person to person contact)
most common in children (5-10 year olds)
What are the causes of tinea capitis?
fungi called dermatophytes
-prefer warmth and moisture so they thrive on sweaty skin
(not super relevant to the scalp)
What is the treatment for tinea capitis?
oral antifungals taken for ~6 weeks
-terbafine HCl (Lamisil)
-griseofulvin
doc might also prescribe a medicated shampoo with the oral med
-helps to remove the fungus and prevent spread of infection
-contains ketoconazole or selenium sulfide
-important to note it wont kill the fungus
What is the presentation of tinea corporis?
superficial fungal infections of the skin
begins as a small round, red spot on face, neck, trunk, or limbs
usually on smooth and hairless areas
gradually expands outward in circular fashion with a raised, scaly, erythematous border and a clear central area
itchiness and burning sensations are common (possibility to be asymptomatic)
True or false: tinea corporis tends to affect men more than women
true
How is tinea corporis spread?
skin to skin contact with infected humans or animals (most commonly dogs, cats, guinea pigs, horses)
What is the treatment for tinea corporis?
topical azoles
-clotrimazole
-miconazole
-ketoconazole (Rx)
topical allylamines
-naftifine (Rx, USA only)
-terbafine (Rx)
ciclopirox (Rx)
Which dosage form is preferred for tinea corporis?
creams and solutions
powders and sprays not preferred due to concern of contact time
What is the rule of thumb for duration of OTC topical antifungals for tinea corporis?
use the product BID until the area clears and then add on a few extra days/a week of treatment
When treating tinea corporis with an antifungal should you only treat the active area?
no
apply a bit beyond the active area to ensure you are hitting all the fungus
What are the OTC treatments for tinea corporis?
Tinactin (tolnaftate 1%)
-ringworm considered to be off-label
Micatin (miconazole 2%)
-mentions ringworm on the package
Canesten (clotrimazole 1%)
-you can use the vaginal version if the foot version is shorted
-mentions ringworm on the package
If the 4 week OTC treatment of tinea corporis is undesirable in the eyes of a patient, what can you do? Why?
prescribe Terbafine 1% cream or spray
-dosage regimen more convenient, OD for 7D
What are the directions for use of terbafine 1% for tinea corporis?
OD for 7 days (two week treatment provides slightly better results than one week)
apply to clean, dry, affected area and surrounding area
children>12yrs and adults
True or false: terbafine 1% is the only thing a pharmacist can prescribe for tinea corporis
false
there is also ketoconazole 2% cream
What does MedSask say about topical steroid and antifungal combination for tinea corporis?
not recommended
the itch caused by tinea infections subsides fairly soon after topical antifungal treatment beings
What is the popular name of tinea pedis?
athletes foot
How is athletes foot spread?
person to person through contaminated towels, clothing or surfaces
popular in humid places like showers, pools, and change rooms
Where is the most common spot for athletes foot?
most commonly in between the toes
may spread to the instep or sole
What is the presentation of athletes foot?
cracked skin or scaly with blisters
inflammation
itching/burning sensation
What are risk factors for developing athletes foot?
direct contact with infected people or animals
conditions of increased moisture
genetics
impaired immunity (HIV, diabetes, chemo)
barefoot in public areas
True or false: you do not need to see a patients foot to proceed with an OTC consult
true
What do we call athletes foot when it migrates to the sole of the foot?
moccasin type infection
What should we do if we come across a case of moccasin type athletes foot?
refer to MD
Which condition is indistinguishable from athletes foot?
candidiasis
-yeast infection
-far less common
-same treatment
If we hear “yeast infection”, what are we thinking?
vaginitis
thrush
intertrigo
What is erythrasma?
chronic skin condition affecting the skin folds
caused by bacterial infection
When do we refer athletes foot to a doc?
lesions are:
-extensive (top and bottom of feet are affected)
-severe inflammation
-weeping or purulent
-painful
-disabling
no improvement after 1wk of pharmacological treatment
patient is diabetic
fungal nail infection is present
What are some non-pharmacological treatments for athletes foot?
skin should be kept dry to help stop infection from spreading
wear cotton socks
avoid going barefoot in public
avoid scratching feet
non-medicated powders may help absorb moisture
Which dosage form is preferred for athletes foot?
creams or solutions
-again, worrying about the contact time of powders
What are the OTC treatments for athletes foot?
tolnaftate 1% (Tinactin)
clotrimazole 2% (Canesten)
miconazole 2% (Micatin)
What are the directions for use of products for athletes foot?
apply to clean and dry affected area
apply beyond affected area
use BID until clear and then a few days/1wk
What can we prescribe for athletes foot?
terbafine 1% cream (children>12 and adults)
-OD for 7D
terbafine 1% spray
-OD for 7D
ketoconazole 2% cream (children>12 and adults)
-BID for 4-6wks
What are the signs and symptoms of tinea cruris?
large round, red, well-defined patches on the upper inner thigh and groin area
genitals spared
burning and itching are common
often co-morbid with tinea pedis and tinea unguium
What is the common name of tinea cruris?
jock itch
Which conditions can resemble tinea cruris?
candida intertrigo
-yeast infection which covers penis and scrotum and groin
area with red papular lesions
seborrheic dermatitis
-yellow, greasy, scales on scalp and may extend to rest of
body
psoriasis
-red spots with thick silver scales
Describe erythrasma.
chronic superficial infection of the intertriginous areas of the skin
more frequently in tropical areas
other than colour, can be symptom-free or just a bit of itch
What is the treatment for erythrasma?
topical erythromycin or clindamycin, or fusidic acid or miconazole cream
What are some non-pharmacological treatments for tinea cruris?
keep skin dry to help stop infection from spreading
wear loose fitting, cotton clothing
non-medicated powders to help absorb moisture
True or false: when using non-medicated powders to help absorb moisture, cornstarch is a good option
false
cornstarch could be a substrate for fungus
What are the OTC treatments for tinea cruris? Which one product is an off label use?
tinactin (off label)
canesten
micatin
What can we prescribe for tinea cruris?
terbinafine 1% cream/spray
-OD x 7D
ketoconazole 2% cream
-OD for 2-4wks
True or false: we cannot prescribe ciclopirox for tinea cruris
true
What is onychomycosis?
fungal toenail infection
What are the symptoms of onychomycosis?
initially, complains about appearance with no physical symptoms
as it progresses it can interfere with walking, standing, etc
pain, discomfort, loss of self-esteem
What percentage of abnormal appearing nails are due to onychomycosis?
50-60%
How fast do toenails grow?
1.62mm per month
if you lose a toenail, it can take up to a year and half for it to grow back
What should patients expect with treatment duration of onychomycosis?
topical: up to 12 months
oral: 2-3 months
What are the treatments for onychomycosis?
efinaconazole 10% solution (Jublia)
-Rx
propylene glycol/urea/lactic acid topical solution
-OTC
True or false: topical ciclopirox has limited efficacy for onychomycosis
true
Why is topical ciclopirox not a great treatment for onychomycosis?
limited efficacy
requires weekly nail trimming and removal of lacquer build up
requires monthly debridement by podiatrist/MD
pharm cannot prescribe
Differentiate between DLSO, SWO, and PSO.
DLSO: distal lateral subungual onychomycosis
-under the tip and side of the nail
-most common type (90%)
SWO: superficial white onychomycosis
-7% of cases
-more common in children
PSO: proximal subungual onychomycosis
-6% of cases
-white discoloration at proximal nail fold beneath nail bed
What is the number of nails involved where we must refer someone to the doctor for onychomycosis?
3
