Onychomycosis
Hai Ho, M.D.
Diagnosis?
Pitting
•Nail involvement – 10-50%
•Usually along with skin lesions,
but could be alone
•Could occur in eczema, fungal
infection, and alopecia areta
Psoriasis
Diagnosis?
Pitting
Onycholysis
Yellow psoriatic
debris under the
nail causing nail
separation
Psoriasis
Diagnosis?
Nail matrix
involvement leading
to nail deformity
Psoriasis
Diagnosis?
Onycholysis


Painless separation of
the nail from the nail
bed
Causes: trauma (long
nail in women),
hyperthyroidism,
prolonged immersion,
psoriasis
Diagnosis?
Traumatic onycholysis
Onycholysis


May have secondary
candida infection
Treatment



Avoid long nail
Tinture containing
miconazole under nail
Fluconazole for
resistant case
Diagnosis?
Nail hypertrophy
 Cause: tight-fitted
shoes or chronic
trauma
 Treatment: filing or
removing the nail with
phenol
Diagnosis?
Leukonychia punctata
 Cause by cuticle
manipulation or other
mild trauma
Diagnosis?
Leukonychia
Diagnosis?
Distal splitting nail
 Analogous to peeling of
dry skin
 Affected 20% of adults
 Associated with water
immersion and use of
polish remover
 Treatment


Moisturizer
B-complex vitamin biotin
(2.5mg/day) for brittle nail
Diagnosis?
Pincer nail
 Due to ?tight shoes
 Treatment


Nail removal
Reconstruction of nail
unit
Diagnosis?
Habit-tic onycholysis
Diagnosis?
Median dystrophy
Moral of the story


Cannot diagnose onychomycosis by
visualization alone
>50% of fungal-looking nail do not have
fungal infection
Common organisms in
onychomycosis?

Dermatophytes



Trichophytum rubum
Trichophytum mentagrophytes
Contaminants or nonpathogens

Aspergillus, Cephalosporium, Fusarium, and
Scopulariopsis
Patterns of infection
Distal subungual onychomycosis



Most common
Fungi invade the
hyponychium and
grow in the substance
of nail plate, causing
it to crumble
Hyperkeratotic debris
causes nail to
separate from the bed
Distal subungual onychomycosis
Linear channel


Infection advance
proximally
Characteristic feature
of fungal infection
White superficial onychomycosis
Commonly Trichophyton mentagrophytes
Nail - white, soft, powdery
White superficial onychomycosis

Nail


not thickened
not separated from the
nail bed
Proximal subungual onychomycosis

Commonly
Trichophyton Rubrum


Invade the substance
of nail plate, not the
surface
Hyperkeratotic debris
causes the nail plate
to separate from the
nail bed
Proximal subungual
onychomycosis is associated with
what disease?
HIV
Candida onychomycosis



Almost exclusively in
chronic
mucocutaneous
candidiasis
Generally infect all
fingernails
Linear yellow or
brown streaks grow
and advance
proximally
Candida onychomycosis
Yellow areas with
hyperkeratosis
Laboratory tests?



KOH – improve detection with
fluorochrome which binds with chitin in
fungal cell wall and fluoresces
Culture – gold standard
Histological examination by periodic acidSchiff (PAS) staining – equal to culture
Obtaining specimen
Clip the nail for PAS & culture
Subungal debris for KOH & culture
Fungi reside in the nail plate and cornified cells in the nail bed
Hyphae in the nail plate may not be viable, so obtain specimen from nail
bed for culture
KOH examination
Hard nail plate and debris could
be softened overnight with KOH
Artifacts – lipid droplet between
cells; eliminated by heat which
separates cells
Culture

Sabouraud's with antibiotics



Antibiotics suppress bacterial contaminants
Medium turn from yellow to red in 7-14 days
– alkaline released by dermatophytes turn
phenol (pH indicator) red
ID the organism
PAS staining



In the presence of periodic acid, hydroxyl
group of polysaccharide in fungal cell wall
oxidized to aldehyde
Schiff reacts with aldehyde to stain fungal
elements pinkish-red
False-negative – sampling error
Options



Systemic – terbinafine, itraconazole,
fluconazole
Topical
Mechanical
Oral medications
Terbinafine is more effective than
itraconazole and fluconazole
Terbinafine vs. intermittent
itraconazole
80
75.5
70
60
50
40
38.3
30
20
10
0
Cure Rate
Cure rate at 72 weeks
Crawford F, et al. Arch Dermatol 2002; 138:811
Terbinafine
Itraconazole
Terbinafine vs. fluconazole
90
89
80
70
60
50
51
Terbinafine
Fluconazole
40
30
20
10
0
Cure Rate
Cure rate at 60 weeks
Havu V, et al. Br J Dermatol 2000; 142(1):97.
Ineffective oral regimen


Intermittent terbinafine
Greseofulvin
Regimen
Drug
Dosage
Fluconazole (Diflucan)
One 150-mg dose each week for 9
months
Itraconazole (Sporanox)
200 mg/day for 12 weeks for toenails,
6 weeks for fingernails
“Pulse dosing”: 400 mg/day for first
week of each month
Fingernails 2–3 pulses
Toenails 3–4 pulses
Terbinafine
250 mg/day (12 weeks for toenails, 6
weeks for fingernails)
Adverse effect of terbinafine?


Cholestatic hepatitis and blood dyscrasias
LFT and CBC prior to and at 6 weeks
during treatment
Adverse effect of itraconazole?


Hepatitis for continuous but not
intermittent regimen
LFT prior and at 6 weeks during treatment
for continuous, not pulse, regimen
Drug interactions with itraconazole

Cytochrome P450 system




Arrhythmia with quinidine and primozile
Rhabdomyolysis with HMG-CoA reductase
inhibitors, such as atorvastatin
Sedation and apnea with benzodiazepines
Decrease absorption with high gastric pH


Avoid H2-blocker and PPI
Take with food
Fluconazole



Not FDA approval for onychomycosis
First line for candida but could use for
dermatophytes
Check LFT
Prevent recurrence



Prevent tinea pedis – powder to feet,
protect feet in communal shower, change
socks
Avoid trauma by tight shoes
Ciclopirox nail lacquer 8% (PENLAC) 2 to 3
times a week
Ciclopirox nail lacquer 8%
(PENLAC)




Cure rate at 48 weeks – 29%
Apply to affected nail and 5 mm of
surround skin daily
Remove PENLAC with alcohol weekly
Remove infected nail frequently
Mechanical removal


Surgery
Nonsurgical avulsion
of dystrophic nail, not
normal one
Nonsurgical avulsion


Apply 40% urea gel
(Carmol-40 gel, Vanamide
cream) with occlusive
dressing
Remove the entire nail or
cut the affected portion,
followed by curetting to
normal nail in 7-10 days