Superficial Fungal Infections 2 Flashcards
Tinea corporis - Ringworm
transmission
risks
Infection of glabrous (hairless) skin of trunk or limbs (excludes face, hands, feet and groin
● less commonly can affect face - tinea faciei if affects non bearded area of face)
Possible organisms
T. rubrum (most common)
M. canis
T. mentagrophytes
Transmission – Direct skin-to-skin contact (e.g. wrestlers), animal contact, fomite, and
environment
Risks - humid climates, impaired immune states, occlusive clothing, genetic
predisposition
Tinea corporis (Ringworm)
presendation
● Begins as flat, circular scaly spots with central clear
portion
● Raised vesicular red border
○ Can have pustules within the active border
○ May appear more erythematous on lighter skin tones
and hyper pigmented on darker skin tones
● Advances outwards
● Occurs on upper body, extremities
○ May occur on the face (3-4%)
● Usually asymptomatic, occasionally pruritic
Differential diagnosis
ringworm
Impetigo
Seborrheic dermatitis
Eczema
Psoriasis
Allergic contact dermatitis
Lichen Simplex
Lyme disease (lacks scales, central clearing at site of tick bite)
Tinea capitis
Pityriasis rosea (small, scaled lesions in Christmas tree trunk distribution)
Tinea corporis (ringworm) - Treatment
Similar to Tinea cruris
Usually used for a longer treatment period (~4 weeks)
(exception - topical terbinafine x 1wk)
Tinea Unguium- ONYCHOMYCOSIS
Common finding in the adult population (~6%)
Increased prevalence:
● elderly, diabetic patients, immunocompromised
Other risk factors:
● Hyperhidrosis, peripheral vascular insufficiency, nail trauma, occlusive
footwear, swimming, barefoot, avid athletes, living with infected family
member, tinea pedis (1/3 of cases associated with tinea pedis)
Organisms:
T. rubrum (50-70%)
T. mentagrophytes (5-17%)
E. floccosum
Many other dermatophytes
Rarely caused by Candida or molds (eg aspergillosis)
Tinea Unguium
presendation
Usually toenails, but can affect fingernails
Nail plate may separate from the nail bed (onycholysis)
Subungual area thickens (subungual hyperkeratosis)
Nail plate turns yellowish/brown or white
Need physician to diagnose via nail clipping:
● Culture
● Direct microscopy (KOH examination)
● Biopsy
Hallmark signs:
Thickening
Discoloration
Separation
Types of Tinea Unguium
● There are 3 major subtypes of OM:
○ Distal lateral subungual onychomycosis (DLSO); the
most common form
○ Superficial white onychomycosis (SWO) - 10%
○ Proximal subungual onychomycosis (PSO) - least common
Tinea Unguium
Differential diagnosis:
red plags
Differential diagnosis:
Many different causes of nail bed changes –diagnosis difficult based on clinical
appearance
● Psoriasis, eczema, trauma, lichen planus, yellow-nail syndrome, drug (e.g. tetracyclines, cancer
chemotherapy), squamous cell carcinoma
When to refer for further assessment?
● If patient has not been previously diagnosed.
● >3 nails affected or Involvement of > 50% of nail – oral therapy recommended.
● Suspected drug or disease induced.
● Patient immunosuppressed.
● Poorly controlled diabetes or patients with peripheral vascular disease.
● <18 yo
● Nail presentation: Trauma to nail, pitting, lifting
Using APA - have
they been dx with a
nail clipping yet?
Tinea Unguium - Nonpharm recommendations
Wear footwear and socks that minimize humidity
Keep nails clean and cut short
Avoid sharing nail clippers or footwear
Apply emollients on cracked skin to reduce further entry points for fungus
Control chronic health conditions (diabetes mellitus or peripheral vascular
disease)
Mark margin of fungal growth on nail to monitor efficacy of treatment
Tinea Unguium
To treat or not to treat?
Consider type and severity, extent of disease, age and underlying medical
conditions, drug interactions and adverse effects, cost
Topical therapy:
Less effective than systemic therapy
Poor penetration, recurrence common after stopping, poor adherence
Oral therapy:
Most commonly employed first line especially for more extensive nail involvement
Surgery:
Nail avulsion (last resort and not always successful at eradicating fungus)
TOPICAL - Ciclopirox olamine 8%
DORMANT ON DPD
Application of Jublia
Can Jublia be used on fingernails or just toenails as indicated in
q
8mL bottle = ~380 applications/drops
Product monograph states to only be used for toenails and is not indicated for
fingernail onychomycosis.
Note: Emtrix can be applied to both toe and finger nails
Topical - Efinaconazole 10% solution - Jublia®
● Used for mild to moderate cases of onychomycosis . Blocks production of ergosterol
(important part of fungal membrane), leading to loss of function, death and reduction in
infection
● Option for those with contraindications to oral therapy
● Mycological cure rate 54% and clinical cure rate 17%
● Enhanced penetration compared to ciclopirox
Directions:
● Apply 1 application to the dry toenail, preferably at bedtime for up to 48 weeks. (Big
toenail 2 applications (see next slide). Afterwards, ensure to use the brush to spread
around the entire toenail (cuticle, folds of nail and sides/underside of toenail and on the
end of toenail and surrounding skin). Allow to dry for 30 seconds
● No need to remove the medication weekly due to lack of medication build up
● No need to debride or remove diseased nail
● Monitor for application site vesicles and dermatitis (redness, itching, burning, stinging in
surrounding areas)
Mycological cure = 54%, clinical cure = 17%
Topical - Propylene glycol, urea and lactic acid (Emtrix)
Non-prescription topical solution
● Use: Applied daily on infected nail and under free edge.
Cover nail with thin layer and allow to dry for a few
minutes. Used for up to 24 weeks. Use in mild cases
● Minimal systemic absorption
● Transient irritation to skin next to affected nail,
whitening of nail. Nail may become loose and detach.
● Mycological cure 27% (with < 50% nail involvement)
Tinea Unguium - Rx
Oral terbinafine (Lamisil®
)
Drug of choice: best efficacy, tolerability, lower risk of drug interactions compared to other oral options
Dose: 250mg daily (6-12 weeks for fingernails; 12-24 weeks for toenails)
○ Mycological cure 70%, clinical cure rate 38%
○ Twice as effective compared to itraconazole pulse dosing after 12 weeks
○ Remains in nails for up to eight months after therapy is stopped
Monitor: GI upset, headache, rash, loss smell/taste, hearing disturbance, hepatotoxicity. Serious - AST/ALT
hepatotoxicity, SJS/toxic epidermal necrosis, neutropenia
○ Labs - at baseline LFTs and at 4-6 weeks
Drug Interactions - inhibits CYP2D6
Tinea Unguium - Rx
Itraconazole (Sporanox®
)
Dose:
Pulse Dosing- 200 mg twice daily x 1 week/month, repeat 2-3 cycles. May result in lower risk of
therapy discontinuation but efficacy similar to continuous dosing
Continuous dosing - most commonly prescribed
200mg daily x 6-8wk (fingernails)-12 weeks (toenails)
● Detectable in nails within 1-2 weeks of therapy
● Remains in the nail plate even after therapy is stopped
● Mycological cure rate 54%, clinical cure rate 14%
● Many drug interactions (STRONG CYP3A4 INHIBITOR)
● Contraindication: ventricular dysfunction or heart failure
Monitor - dose related GI upset, edema, hypokalemia, headache, rash, increased ALT/AS
Serious: SJS, hepatotoxicity,heart failure
Labs - liver enzymes monthly
