Download Superficial Fungal Infection

Fungal Infection of the Skin
November 24th , 2003
Michael Hohnadel D.O.
Duncanville Dermatology
Clinic
Dermatology Residency
KCOM Dermatology
Department
Topics Covered
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Basic diagnostic techniques
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KOH
Culture
Woods light
Tinea infections with special attention to scalp, feet and
nails
Tinea Versicolor
Candidiasis
Differentials to consider.
Basic Treatment
Questions
1. What is a Wood’s light useful for ?
2. If I think it might be a fungus but it is KOH negative,
what can be done to prove it ?
3. How do you know the endpoint of therapy when
treating tinea capitis ?
4. How do you know the endpoint of therapy when
treating tinea versicolor ?
5. If a patient has thick ugly nails, what is the chance
that it is classic onychomycosis ?
Diagnostic Tests
KOH Preparations
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Skin
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Two slides or slide and #15 blade.
Scrape border of lesion.
Apply 1-2 drops of KOH and heat gently
Examine at 10x and 40x
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Look for hyphae
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Focus back and forth through depth of field.
Clear, Green
Cross cell interfaces
Branch, constant diameter.
Chlorazol black, Parkers ink can help.
Diagnostic Tests
KOH Preparations
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Nails
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Hair
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Thin clipping, shaving or scraping
Let dissolve in KOH for 6-24 hours.
Can be difficult to visualize.
Culture often required.
Directly examined without KOH.
Apply KOH and heat hair until macerated
Look for spores.
Be Persistent !
Tinea Versicolor
Trichophyton
Tonsurans
Tinea Versicolor
Parkers Ink Stain
Watch out for Mosaic Fungus
Mosaic Fungus
Lipid droplets in
interepithelial
spaces and cell
membrane
overlap simulate
fungal hyphae.
Diagnostic Tests
Fungal Cultures
DTM (Dermatophyte
– Yellow to red is (+).
Nickerson’s Media
– Yeast
– Black growth is (+)
Sabouraud’s
– Molds
Media
Test Medium)
Diagnostic Test: Fungal Culture
Example of DTM
Diagostic Test Fungal Culture
Diagnostic Tests
Fungal Culture
Sample Collection
 Scrape
with blade or rub with cotton Q-tip. Nail
clipping or curette.
 Implant in media.
 Cap Loosely, Fungi are aerobic
 Read at 2 weeks and 4 weeks.
Tinea Capitis
Diagnostic Tests
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Wood’s Light
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Tinea Capitis
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Other Areas:
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Blue green florescent with M. Canis.
Not useful for Trichophyton (Most Common)
Useful to diagnose as erythrasma (coral red/pink).
Tinea versicolor may be pale white yellow.
Less helpful if patient recently bathed.
PAS stain of skin or nail clipping.
Woods Light – M. Canis
Woods Light - Erythrasma
Different Types of Infection
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Dermatophyte Fungal Infection
– Tinea Capitis
– Tinea Pedis
– Tinea Unguium (Onychomycosis)
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Tinea Corporis
Tinea Faciales
Tinea Cruris
Tinea Manuum
Tinea Vesicolor
Candidiasis
Tinea Capitis
Tinea Capitis
• Children most common cases.
• Most Common Organisms:
• T. Tonsurans - acounts for 90% in U.S.
• M. Canis - seen in children with infected animals.
•Adults not infected.
• M. Audouinii - grey, broken shaft tinea
Tinea Capitis
Presentations of Tinea Capitis
1. Non-inflammatory ‘black dot’ type
2. Seborrheic type
3. Pustular
4. Inflammatory (Kerion)
Tinea Capitis
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Black Dot Type
Large Areas of Alopecia without
inflammation
 Mild scaling
 Occipital adenopathy
 Black dot hairs.
 At first glance may look like Alopecia areata
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Tinea Capitis
Tinea Capitis
Seborrheic type
 Common–
resembles dandruff
 Close exam for broken hairs, black dots
 Adenopathy
 Frequently negative KOH (70%)
 Culture often necessary for DX
Tinea Capitis
Kerion
 Inflamed,
Boggy and tender.
 M. Canis common etiology
 Systemic symptoms: Fever, Adenopathy.
 Scaring alopecia may occur
 KOH often negative
 May look bacterial
Tinea Capitis - Kerion
Tinea Capitis
Pustular
•Discrete pustules and crusted areas
•No significant hair loss or scale
•Often KOH negative
•Frequently treated as bacterial at first
Tinea Capitis Diagnosis
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History
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Morphology of lesion
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Blue green.
Hair Shaft Exam
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Broken hairs, black dots, localized.
Woods Lamp
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Close contacts, pets, duration.
Endo/Exothrix
Culture
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Plucked Hair shafts, Q-tip or tooth brush.
Normal Hair
Tinea Capitis - Endothrix
Tinea Capitis - Exothrix
KOH and ‘Quick Ink’
M. Canis
Tinea Capitis Treatment
•Must treat hair follicle
•Topical not effective
•Systemic agents
•Griseofulvin for children – liquid with good taste.
•Imidazoles, terbinafine.
•Steroids for inflamed lesions like Kerion.
•Treat until no visual evidence, culture (-)… plus 2 weeks
•Average of 6-12 weeks of treatment.
•Examine / treat family in recurrent cases.
Tinea Pedis and
Manuum.
T. Rubrum most common etiology
•Dull erythema with pronounced scale.
•Leading edge of scale not as common.
•Two feet one hand involvement.
•T. Mentagrophytes causes inflammatory
tinea pedis
•Vesicles and bullae.
General Morphology
Tinea Pedis
Tinea Pedis
General Morphology
Tinea Manuum
Two feet one hand
Tinea Pedis
•Groups: M > F. Young and middle aged.
•Patient is susceptible to reoccurrence
•Onychomycosis and tinea pedis associated.
•Differential:
•Eczema, contact dermatitis
•Psoriasis.
•Erythrasma and Candida (esp in web spaces.)
•Pitted keratolysis
Tinea Pedis Diagnosis
•PE/History – onychomycosis, contacts, med cond.
•KOH exam – Thick scale, no leading edge
•Woods Light - Helps to differentiate from erythrasma
•Culture
•Remember: ‘hand eczema’ may be a
dermatophyte infection of hands or id reaction
from tinea at another location.
Tinea Pedis: Treatment
•Dry Feet
•Alternate shoes, Absorbent powders, Change socks
•Scale my be reduced with keratolytic
•SAL acid, Lactic acid, Carmol
•Topicals and/or Systemics.
•Topical: naftine, lamisil, mentax may be more effective than
azoles. Steroids if inflamed.
•Systemic allyamines or azoles
•Treat secondary bacterial infections.
•Steroids for severe inflammation and ID.
General Morphology
Onychomycosis
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15-20% of those between 40-60 yrs. infected.
No Spontaneous remissions
General Appearance:
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Typically begins at distal nail corner
Thickening and opacification of the nail plate
Nail bed hyperkeratosis
Onycholysis
Discoloration: white, yellow, brown
Edge of the nail itself becomes severely eroded.
Some or all nails may be infected
Often accompanying tinea pedis
Onychomycosis
4 Types:
1.
2.
Distal Subungal
White superficial
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3.
Proximal Subungal
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4.
T. Mentagrophytes and molds
Chalky white patches
May indicate HIV infection
Candidaonychomycosis
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Normally hands with accompanying paronychia
Onychomycosis
Onychomycosis with Onycholysis
White Onychomycosis
Candidaisis of nail
Paronychia
Onychomycosis
Differential Diagnosis: (50% of ‘thick nails’ not classic fungus.)
•Allergic contact (nail polish, food items)
•Psoriasis
•Lichen Planus
•Molds
•Nail dystrophies (ex – nephrogenic)
•Drugs
Onycholysis from Contact
Dermatitis to Artificial Nails
Psoriasis
Middle of nail, oils spots, pitting.
Psoriasis
Lichen Planus
Onycholysis from wet - dry
Pseudomonas of nail
Terry nails ‘half and half’
Molds
Bowen’s disease of the Nail
Onychogryphosis
Diagnosis of Onychomycosis
Try to identify fungi before oral therapy
1. KOH of nail clipping
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May need some time to dissolve nail.
2. Culture
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DTM - dermatophytes
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Sauborauds – Molds
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Nickerson – Yeast
3. Nail clipping for histology and PAS staining if above is
negative and clinical suspicion is high.
Curettes for Specimen Collection.
Treatment of Onychomycosis.
Debridement of infected area helps penetration / comfort.
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Mechanical
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Urea products (ex carmol)
Topical Treatment:
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Can be effective for limited involvement and for
prevention.
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Agents
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Penlac (every day for one year)
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Mycocide Nail solution
Treatment of Onychomycosis
Oral therapy
•Effective. Relapse rate 15-20 % in one year.
•Lamisil 250mg. 6 weeks/12 weeks.
•Baseline labs and one month.
•CBC (neutropenia), Liver function.
•Itraconazole 200 mg /day. 6 weeks/12 weeks
•Baseline labs and one month. Similar to lamisil.
•Pulse dosing fingernails - (200 mg bid 1 wk q mo.) x 2
•No lab monitoring needed
Treatment of Onychomycosis
Notes on Therapy
• Other Azoles require longer therapy.
• Nails will not appear clear at end of
therapy
• Measurements and digital photography
verify effectiveness.
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For you and for patient
General Morphology
Tinea Corporis
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Papulosquamous
Erythematous
Annular
Scaling
Crusting
‘Ringworm’
General Morphology
Tinea Faciales
General Morphology
Tinea Cruris
General Morphology
Tinea Versicolor
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Numerous, well-marginated, oval-to-round
macules with a fine white scale when scraped.
Pigmentary alteration uniform in each
individual.
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Scattered over the trunk and neck. Seldom the
face.
Pityrosporum orbicularis, M. furfur
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Red
Hypo pigmented
Hyperpigmented
Normal flora of skin
Asymptomatic.
Tinea Versicolor
More
apparent
in the
summer.
Tinea
Vesicolor
Hyperpigmented
Variety
Looks Like: intertrigo,
erythrasma ….
Tinea Versicolor - Differential
•Vitiligo
•Pityriasis Alba
•Pityriasis Rosea
•Nummular Eczema
•Psoriasis
•Idiopathic guttate hypomelanosis
Vitiligo
White
without
scale.
Pityriasis Alba
Frequently on face,
KOH neg. Few
lesions.
May have fine white
scale.
Pityriasis Rosea
•Papules or
plaques with
Collarette of
scale, KOH (-),
Woods light
neg. HX.
Guttate Psoriasis
Idiopathic guttate hypomelanosis
•White,
small, no
scaly, age.
Tinea Versicolor
Diagnosis:
•Scrape lightly – fine white scale
•KOH Positive for short hyphae and spores
(Spaghetti and meatballs)
•Woods Light – pale yellow white fluoresce.
•Culture rarely done.
Tinea Versicolor
Tinea Vesicolor – Woods Light
Yellow White
Tinea Versicolor Microscope
Tinea Versicolor-Treatment
Topicals for limited involvement.
•Selenium Sulfide Shampoos: lather 10
minutes wash off x 7 days.
•Ketoconazole 2% shampoo: 5 minutes 1-3
days.
•Imidazoles topicals to body qd-bid for 2-4
wks.
•Terbinafine spray.
Tinea Versicolor-Treatment
Oral for extensive
•Itraconazole, fluconazole,
ketoconazole.
•Dosing varies: single dose to 5-10 days of
therapy.
•Likes gastric ph for absorption.
•Avoid bathing with 12 hours of ingestion.
Tinea Versicolor-Treatment
Notes
•Hypopigmentation resolves slowly
•No scale when scraped indicates cure.
•Sunlight helps restore pigment
•Prophylaxis before summer in some patients.
•Selenium shampoo’s
•Q month orals
Candidiasis
•Candida Albicans
•Normal Flora
•Occurs in moist areas especially where skin touches.
•Presentation: primary lesion is a red pustule.
•Most Common: pustules dissect horizontally through the
stratum corneum leaving a red, glistening denuded surface
with long continuous border with satellite lesions.
•May also present as an eruption of multiple pustules
which become erythematous papules between skin folds.
Candidiasis
•Immunosuppression of any type (disease,
steroids), D.M., Antibiotics or receptive
environments predispose.
•Diagnosis: History of predisposing factors
and/or classic appearance of lesions at typical
locations.
•Red and glistening in intertriginous area esp in
predisposed individual think candida.
Candidiasis
Candidiasis
Difficult to be sure in Web spaces.
Candidiasis
Differential:
1. Erythrasma – likes skin creases
2. Eczema – may look like pustular candida
3. Bacterial folliculitis – as above
4. Psoriasis – gluteal cleft
5. Tinea – same locations
Candidiasis
•KOH for pseudohyphae and spores
•May be impossible to tell visually from tinea.
•Woods Light
•Culture. Nickersons (+)
•Remember yeast part of normal flora.
•Add up the evidence
Candidiasis
Treatment of Candidiasis
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Keep dry – Z-sorb powder, cotton ball between
toes.
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Topical – azoles.
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Occasionally co-administration of a weak topical
steroid may be helpful.
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Diaper rash
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Angular chelitis.
Treat co-existent bacterial infection if present.
THE END