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Medical dermatology Dan > Fungal infections Dan > Flashcards

Fungal infections Dan Flashcards

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1
Q

T/F

Interdigitial tinea pedis is common in young children

A

False
Rare
think of psoriasis

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2
Q

How can fungal disease be broadly classified in derm?

A

Superficial mycoses - involve SC, hair and nails
Subcutaneous mycoses – involve dermis or subcutis
Systemic mycoses (less of a derm problem)

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3
Q

What are the main superficial mycoses?

A 
Non-inflammatory group
- Pit versic, Pit folliculitis
- Tina nigra
- Black or white piedra
Inflammatory group
- Dermatophytoses
- Non-dermatophyte superficial mycoses
- Candidoses
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4
Q

What are the main subcutaneous mycoses?

A 
Sporotrichosis
Cryptococcosis
Chromoblastomycoses
Phaeohyphomycoses
Mycteoma
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5
Q

T/F

Yeasts form true hyphae

A

False
only fungus forms true hyphae - may or may not have septae (mark division between neighbouring cells)
Yeast can form pseudohyphae - due to incomplete budding they have constrictions which mimic septae of true hyphae

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6
Q

What organisms cause Pityriasis versicolour and Pityrosporum folliculitis?

A

Malassezia furfur (old name was pityrosporum ovale) or sometimes by M. globosa, sympodialis or restricta

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7
Q

T/F

The normal commensual amount of malasezzia spp on the skin can be detected by skin scraping and KOH prep

A

False
too few to pick up with scrape
alos mainly yeast (spore) form normally but in Pit versic get many Mycelial forms (hyphae)

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8
Q

T/F

Malsaezzia spp feed on sebum

A

True
lipophilic
so less common in kids but common in teens

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9
Q

What are risk factors for Pit versic?

A 
humidity
warm temps
excess sweating
oily skin (seborrhoea)
poor nutrition
immunodeficiency
steroid use
pregnancy
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10
Q

T/F

neonatal cephalic pustulosis is thought to be due to M. sympodialis

A

True

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11
Q

T/F

Seborrheoic dermatitis is thought to be triggerd by M. sympodialis

A

False

More assoc w/ M. furfur, globosa and restricta

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12
Q

T/F
Pityrosporum folliculitis is due to specific types of malasezzia (furfur and/or globosa) growing in the hair follicle in yeast form only, no hyphae, causing local inflammation

A

True

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13
Q

T/F

In kids pit versic often affects the face

A

True

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14
Q

T/F

bright yellow fluorescence can sometimes be seen on Wood’s lamp exam of pit versic

A

True

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15
Q

T/F

The papules of pityrosporum folliculitis often have a central white plug of pus

A

False

often have a central white plug of keratin

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16
Q

Who is at increased risk of of pityrosporum folliculitis?

A 
young women
Down’s syndrome
immunosuppressed
after antibiotics esp doxy
Acne pts esp if given doxy
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17
Q

How is KOH prep performed?

A

Wipe slide with alco wipe and dry
Scrape scale onto slide
Add drop of 10-30% KOH
can counterstain with chlorazol black E
or gentle warming to ‘clear’
+/- Calcofluor white (fluoresces apple-green)
examine under brightfield microscope or under UV if calcofluor used
For pit folliculitis can express follicle contents onto slide and prepare as above to look for spores

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18
Q

Treatment ladder for pit versic/pit follliculitis

A

Advise;
o High rate of recurrence esp if risk factors continue
o Pigment changes take weeks-months to resolve
Address risk factors and treat if possible
e.g. keep cool, avoid sweating/shower ASAP after sweating, stop antibiotics/immune supression, improve nutrition
Antifungal shampoo/lotion best if widespread;
Ketoconazole shampoo (Nizoral) 2% daily for 10 days or leave on overnight and wash off then rpt after 7 days
Econazole lotion 1% (Pevaryl foaming lotion) nocte for 3 days leave on overnight then wash off + rpt at 1+3 months (3 days, 3 times)
2.5% Selenium sulphide shampoo (selsun gold) – leave on 20mins and wash off daily for 2 weeks – do not leave on overnight
50% propylene glycol in water (dries skin oils but often irritates) – apply with guaze twice a day for 2 weeks
If more localised can use cream; Any azole fine
May need to continue topical once a week as preventer
Systemics if resistant;
Fluconazole – 400mg single dose or 300mg/wk for 2-4 wks or 1-200mg/day for 3 weeks
Itraconazole – 200mg/day for 1 week (v expensive)
May need once monthly oral Rx to maintain remission – Flucon 300mg or Itra 200mg
If hyperseborhoea consider Acitrein/Iostretinoin or OSP or spiro in women but assess for hyperandrogenism first in women with hyperseborrhoea

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19
Q

What organism causes tinea nigra?

A

Hortaea Werneckii

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20
Q

T/F

Tinea nigra is a form of superficial phaeohyphomycosis

A

True
So is Black piedra - Piedraia hortae
Hortae means garden - in both cases organims are found in soil

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21
Q

What are the associations of tinea nigra?

A

No associations

occurs in kids>adults

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22
Q

T/F

Tinea nigra is rarely scaly

A

False

can have little scale, lots or even be thick and velvety

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23
Q

T/F

Tinea nigra most often occurs on ams and fingers

A

True

can be anywhere

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24
Q

T/F

abundant brown, branched hyphae are seen on KOH prep of tinea nigra

A

True

Hyphae have close septae and elongated budding cells

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25
Q

Whats the management of tinea nigra?

A 
Can scrape off with scalpel blade
Keratolytics or topical antifungals;
Keratolytics – Whitfields’ ointment (6% Benzoic acid, 3% sal acid)
Azole or allylamine topical antifungals
No need for systemics
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26
Q

T/F

Piedra is a superficial infection of the hair shaft

A

True

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27
Q

What are the organisms for black and white piedra?

A

Black piedra - Piedraia hortae – found in soil
(name simialr to tinea nigra - also brown)
White piedra - Trichosporon beigelii spp.
‘try a white bagel’
(now known to be made up of at least 6 different species) - also enviromental pathogen but can be a commensal

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28
Q

T/F

Positive culture for Trichosporon beigelii is always pathological

A

False

can be commensal

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29
Q

T/F

T. Beigelii spp can cause systemic disease in immune suppressed

A

True

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30
Q

T/F

Adults in tropical climates are most affected by Piedra

A

False

kids in tropical climates

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31
Q

What are the clinical appearnce of piedra infections?

A

Black piedra;
Scalp, face, sometimes pubic
causes asymptomatic brown-black nodules on hair shafts – can envelope shaft if large enough
Nodules are firmly adherent and can get breaks in hair at site of nodules

White piedra;
Face, axillae, pubic, sometimes scalp
grows within and outside of shaft forming a sheath-like nodule
- Less nodular than black piedra
White colour or can be red/green/light brown
Loosely adherent to hair

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32
Q

What does Dematiaceous mean?

A 
Means dark coloured; brown-black fungi
eg.
Horteae werneckii (tinea nigra)
Piedraia hortae (black piedra)
Chromoblastomycosis organisms
Phaeohyphomycosis organisms
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33
Q

What is a ‘Crush preparation’?

A

cut hair shafts in KOH – the nodules (of piedra etc) are crushed as the hairs are mounted on the slides for microscopy

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34
Q

T/F

White piedra is caused by Dematiaceous fungi

A

False

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35
Q

What are DDs of piedra?

A 
pediculosis capitis (nits on hair)
hair casts
pubic lice
trichomycosis axillaris/pubis
trichorrhexis nodosa
scales of psoriasis/seb derm or pityriasis amiantacea
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36
Q

What is Rx of piedra?

A

Cut affected hairs
Antifungal shampoo – 2% ketoconazole
Oral terbinafine in resistant cases

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37
Q

T/F

Dermatophytes live on keratin

A

True
produce keratinases and like cool temps of skin surface
local skin immunity also usually prevents deeper infection

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38
Q

What are the genera of dermatophytes?

A

Microsporum
Trichophyton
Epidermophyton

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39
Q

T/F

Microsporum spp are mainly anthropophilic

A

False
mainly zoophilic
Out of 16 species, 3 are anthropophilic, 2 are geophilic
The only common anthropophilic microsporum is M. ferrugineum

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40
Q

T/F

Trichophyton spp are mainly anthropophilic

A

True
14 species - 6 are zoophilic
Only 2 common zoophilic species are T. mentagrophytes Var mentagrophytes and T. verrucosum

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41
Q

Which dermatophytes are geophilic?

A

M. gypseum and M. praecox

- live in soil

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42
Q

T/F

Epidermophyton floccosum is zoophilic

A

False
E. floccosum is anthropophilic
This is the only species on epidermophyton in the dermatophyte genera

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43
Q

T/F
Typically zoophilic organisms cause a lot of inflammation and can cause pustules or vesicles – present as acute infections

A

True
geophilic organsims cause moderate inflammation and anthropophilic organisms cause mild or non-inflammatory disease and tend to be chronic presentations

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44
Q

T/F

Sebum inhibits dermatophyte infection

A

True

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45
Q

T/F

All dermatophyte infections except tinea capitis occur mainly in adults

A

True

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46
Q

What are risk factors for dermatophyte infection?

A

Team sports, prisoners, hostels etc
Downs syndrome
Immunosupression/HIV - more severe and recurrent

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47
Q

T/F

Dermatophyte infection M=F

A

False
not true for all types
Tinea pedis, cruris and unguim more in men

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48
Q

T/F

It is always preferable to get a species diagnosis from culture when treating dermatophytes

A

False
simple skin infections usually respond to topicals
- KOH prep can confirm if diagnosis unclear
If plannning systemics shoud get culture

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49
Q

T/F

Nails with onychomycosis should be cleaned with an alcowipe prior to taking clippings for culture

A

True
get rid of secondary pathogens on surface
Clip to most proximal point you can without causing pain
Also scrape under nail with a blade to collect debris

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50
Q

T/F
Dermatophyte samples sne to lab are cultured on Sabouraud dextrose agar at 25-30 degrees and sometimes also at 37 degrees for 2-4 wks

A

True
Identity confirmed by appearance of colonies, microscopic examination of conidia & hyphal patterns and biochemical tests

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51
Q

T/F

cycloheximide-containing Sabouraud media is sufficient for growth of all samples sent for fungal culture

A

False
Fine to grow dermatophytes but can inhibit non-dermatophytes e.g. in onychomycosis so need to use both plain and cycloheximide-containing Sabouraud media

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52
Q

Whihc types of dermaotphyte infection often need biopsy to diagnose?
What special stains are used?

A

Tinea barbae or Majocchi’s granuloma
as fungi deep in follicles
PAS or Grocott silver stain to see fungal elements

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53
Q

What are the commonist dermatophytes to cause tinea corporis?

A

T. rubrum is most common cause
2nd commonest is T. mentag var mentag
But can be any dermatophyte species

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54
Q

When is T tonsurans a common cause of tinea corporis?

A

If a child in the household has tinea capitis

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55
Q

A pt with an inflammatory type of tinea corporis who does outdoor activities is most likely to have what type/species of dermatophyte?

A

Geophilic types

esp Microsporum gypseum

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56
Q

T/F

T verrucosum can be acquired from exposure to cattle

A

True

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57
Q

Which dermatophyte species is acquired from rodents?

A

T. mentag var mentag

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58
Q

T/F

T. concentricum causes concentric red rings of tinea corporis

A

False
T. rubrum causes concentric red rings of tinea corporis
T. concentricum causes tinea imbricata

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59
Q

T/F

hair follicles act as reservoirs for dermatophyte and hairy skin more resistant to treatment

A

True

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60
Q

T/F

Incubation time for tinea corporis is 6-8 weeks

A

False

1-3 weeks

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61
Q

What is tinea profunda?

A

Tinea corporis with a large amount of inflammation like a kerion
Lesions look thick, verrucous or ‘granulomatous/infiltrated’
mycotic Sycosis is a variant - very inflammatory tinea barbae with deep inflammation of follicles like a kerion on the cheek

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62
Q

What is Tinea imbricata? whre does it occur?

A

Tinea corporis due to T. concentricum causes eruption of annular concentric rings and patterns a bit like erythema gyratum repens
In South pacific islands, central and S. America and asia

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63
Q

What is Majocchi’s granuloma? who is at risk?

A

Deep suppurative folliculitis cause by dermatophyte
Presents as red plaque with follicular pustules or nodules
Usually T. rubrum
can be T. violaceum or E. floccosum
At risk are women who shave their legs and have tinea pedis or onychomycosis - Must check their feet!

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64
Q

T/F

T. mentag var mentag commonly causes Id reactions

A

True

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65
Q

T/F

Intertrigo means any infection localised to a body fold site

A

True

bacterial, fungal, viral etc

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66
Q

What are the commonest dermatophytes to cause tinea cruris?

A

T. rubrum
T. mentag var mentag
E. floccosum
Same 3 for tinea manuum and pedis

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67
Q

T/F

Pts with tinea cruris often have tinea pedis

A

True

Must look for it!

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68
Q

T/F

Tinea cruris is common in women

A

False

rare in women

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69
Q

Risk factors for tinea cruris?

A

Tinea pedis/unguium
sweaty
obese
team sports/locker room use

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70
Q

T/F

tine acruris can be uni or bilateral

A

True
Can extend to bottom, waist, thighs (esp T rubrum) or to trunk and legs (esp T ment); E floccosum rarely spreads beyond groin. Scrotum usually spared (thin skin, not much keratin)

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71
Q

T/F

Eczema marginatum is a variant of tinea cruris

A

True
E. floccosum
Well demarcated tinea with vesicles and/or pustules in border

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72
Q

T/F

satellite lesions and scrotal involvement point towards candidal intertrigo rather than tinea cruris

A

True

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73
Q

How is tinea cruris managed?

A 
Loose weight
Keep cool
Loose clothing (less heat)
Dry thoroughly
Talcum powder
Wash contaminated textiles
Treat tinea elsewhere
Clean environment, avoid locker rooms
topicals usually sufficient, may need systemic if inflammatory or extensive or failed topical treatment
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74
Q

T/F

tinea of the dorsal hands is tinea manuum

A

False
tinea manuum is dermatophyte of the palm and/or interdigital spaces
tinea of dorsal hands and feet is considered tinea corporis

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75
Q

Which dermatophytes most often cause tinea manuum?

A

T. rubrum
T. mentag var mentag
E. floccosum
Same 3 for tinea manuum and pedis

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76
Q

T/F

Non-dermatophyte fungi may cause infection resembling T manuum

A

True

Scytalidium dimidiatum and S. hyalinum

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77
Q

T/F

Tinea manuum is often pustular

A

False
usually non-inflammatory with white hyperkeratosis esp of the skin markings
Can be exfoliative, vesicular or papular, unuusal to be pustular but consider in any unilateral hand eruption

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78
Q

T/F

Tinea unguim of fingernails often present if there is tinea manuum

A

True

must check nails and feet!

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79
Q

T/F

tinea pedis of moccasin type often present if there is tinea manuum

A

True

must check nails and feet!

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80
Q

T/F

Bilateral tinea manuum is the norm

A

False
most often unilateral
50% have 2 feet, 1 hand syndrome
must check nails and feet!

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81
Q

T/F

80% of pts with unilateral tinea manuum will have 1 hand 2 feet syndrome

A

Fase

50%

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82
Q

T/F

Tinea barbae is dermaotphyte infection of beard areas of face and neck in men

A

True

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83
Q

T/F

Tinea barbae is usually due to anthopophilic dermatophyte spp

A

False
zoophilic types common - however most common are the trychophyton zoophilic types
T. ment var. ment, T. verrucosum
rather than microsporums which are more commonly zoophilic

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84
Q

T/F

Tinea barbae is often very inflammatory

A

True as zopphilic
Pt may feel unwell and have LNs
Majocchis granuloma may develop or suppurative abscess with sinus tracts
rarely mycotic sycosis (kerion)
can result in scarring alopecia
Anthropophilic types e.g. T. rubrum are more superficial

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85
Q

What are DDs for Tinea barbae (including Majocchis granuloma or mycotic sycosis)?

A 
Sycosis barbae
Bacterial folliculitis or impetigo
HSV/zoster
Pyoderma faciale
Blastomycosis-like pyoderma
Dental sinus tract
Cervicofacial actinomycosis
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86
Q

T/F

Tinea faciei is often a difficult diagnosis

A

True
classical scaly edge often absent
scrape anything red and scaly on face esp resistant/progressive ‘seb derm’

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87
Q

T/F

E. floccosum never causes tinea capitis

A

True

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88
Q

T/F

T. tonsurans is most common cause of tinea capitis in Aus

A

False
M canis most common in Aus (75%),
T tonsurans second (10%)

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89
Q

T/F

The asymptomatic carrier state for tinea capitis often occurs in children

A

False
rarely in children
but common in adults esp after exposure to T tonsurans

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90
Q

T/F

People who are asymptomatic carriers of dermatophyte on their scalp do not need to be treated

A

False
need to treat as can spread infection
topical may surface - need repeat culture after Rx
If not treated use orals

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91
Q

What are the microscopic patterns of tinea capitis infection?

A

endothrix
ectothrix
favus

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92
Q

T/F
Ectothrix infections may fluoresce
Favus should fluoresece
Endothrix never fluoesce

A

True

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93
Q

What are the features of endothrix infections?

what are the main organisms?

A

Non-fluorescent arthroconidia within hair shaft
Anthropophilic species
Nearly always Trychphyton
esp Tonsurans and Violaceum also Soudanense (esp in Africa)
remember ‘TVSets are IN houses’
Clinically can be; scale only/ black dots /alopecia

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94
Q

What are the features of ectothrix infections?

what are the main organisms?

A

Hyphae and arthroconidia grow outside hair shaft – cause destruction of cuticle
Mostly Microsporon
Mostly zoophilic (M. ferrugineum and audouinii are exceptions)
May fluoresce under Wood’s lamp
Clinically can be scaly and patchy alopecia up to kerion

95
Q

T/F

black dot tinea capitis is often caused by endothrix infections

A

True

The hairs are weakened from fungi growing inside so easily breaks off

96
Q

What are the features of Favus?

what are the main organisms?

A

Hyphae and air spaces within hair shaft (no conidia)
Most severe form of tinea capitis
Mostly caused by T schoenleinii – blue-white fluorescence on Wood’s lamp
Clinically thick yellow crusts called ‘scutula’ composed of hyphae and keratin skin debris which develop around follicular orifi
Can lead to scarring alopecia (without a kerion)
Not seen in Aus unless in o/s traveller

97
Q

what are scutula?

A

thick yellow crusts seen in Favus composed of hyphae and keratin skin debris which develop around follicular orifi

98
Q

What are common/important causes of tinea capitis in Aus

A

Cash Allows Very Many TV Sets
M. Canis (cats, dogs)
M. Audouinii (anthropothilic)
M. Verrucosum (from cattle, very slow growing, kerion)
T. Mentangrophytes (quite common, guinea pigs, kerion)
T. Tonsurans
T. Violaceum
(T. Soudanense rare in Aus unless refugee etc)
(T. Schoenleinii rare, favus - rare in Aus unless refugee)
*CAVM are ectothrix, TVS are endothrix

99
Q

What are the species of dermatophyte which fluoresce?

A 
FACDs
T ferrugineum (yellow)
M audouinii (green-yellow)
M canis (green)
M distortum (yellow)
T schoenleinii (blue-white/pale-dull green)
T triple M T
100
Q

What are the clinical patterns of tinea capitis infection?

A

6 types;
Grey patch – patchy alopecia with fine grey scale – esp ectothrix microsporum infections
Black dots - + mild scale - esp endothrix as weakens hair esp Trichophyton esp T. tonsurans
Diffuse scale with minimal alopecia - (resembles dandruff) eg. T. tonsurans
Diffuse pustular variant – patchy alopecia and scattered pustules or folliculitis, can be tender regional lymphadenopathy
Kerion Celsi - severe inflammation in a chronic tinea case; painful boggy mass, solitary or multiple, regional adenopathy common – can cause scaring alopecia esp if antibiotics given which can worsen the condition. Esp zoophilic, large spore ectothrix e.g. T mentagrophytes, T verrucosum
Favus

101
Q

T/F

scalp hairs should be clipped to send for fungal MCandS for tinea capitis

A

False
pluck hairs, dont cut
if fluoresces can send hairs that fluoresce
take brushings from scalp but need to be vigorous (toothbrush, cytobrush, damp gauze) and can only be used to inoculate culture so no microscopy. Best yield is from edges of lesions

102
Q

T/F

pts being treated for tinea capitis may develop an itchy papular dermatophytid reaction esp around helix of ears

A

True

Treat with TCS

103
Q

What are the types of tinea pedis?

A

Soles;
Non-inflammatory moccasin type
Inflammatory vesicular type

Interdigital webspaces;
Interdigital athletes foot type
Ulcerative type

104
Q

T/F

The feet are the most common site of dermatophyte infection

A

True

Interdigital type is most common

105
Q

T/F

Tinea pedis rare in Kids

A

True

but higher insidence if downs syndrome

106
Q

T/F

Tinea pedis rare in cultures where shoes are not worn

A

True

107
Q

What are the common dermatophytes which cause tinea pedis?

A

T rubrum, tonsurans and mentagrophytes var interdigitale

E. floccosum

108
Q

What non-dermatophyte organisms cause tinea pedis – like infections?

A

Scytalidium dimidiatum and S. hyalineum (moccasin & interdigital)
Candida spp. (interdigital)
Fusarium spp. (interdigital)
Cause the interdigital type

109
Q

What is the dermatophytosis complex?

A

Means secondary infection of a tinea; usually bacterial
Often inflammation, maceration, and odour
Often occurs with interdigital tinea pedis esp ulcerative type

110
Q

T/F

Trichophyton mentag var interdigitale commonly causes moccasin tinea pedis

A

False
T interdigitale can cause all the other 3 types of tinea pedis including vesicular dermatophyte of the sole (only cause of this) but not simple moccasin type

111
Q

T/F

T rubrum and E floccosum can cause all types of tinea pedis except the vesicular sole type

A

True
Only Trichophyton mentag var interdigitale causes vesicular dermatophyte of the sole
T. interdigitale can also cause ordinary and ulcerative interdigital types

112
Q

T/F

vesicular dermatophyte of the sole often causes an Id reaction

A

True

113
Q

T/F

vesicular dermatophyte of the sole usually needs oral Rx

A

False

Responds to topicals

114
Q

T/F

Interdigital type tinea pedis often needs antibacterial as well as antifungal Rx

A 
True
As often secondary bacterial infection = ‘dermatophytosis complex’
Condys
bactroban
sometimes oral ABs
\+ topical antifungal
115
Q

T/F

Moccasin tinea pedis responds to topicals alone

A

True
but may need keratolytic as well as antifungal
eg. lactic acid, glycolic acid or urea cream
same for tinea manuum

116
Q

What are the indications for systemic antifungals in tinea pedis?

A

Recalcitrant disease
diabetes
immunosuppression

117
Q

T/F

Onychomycosis is always due to dermatophyte spp?

A

False
onychomycosis can be caused by non-dermatophyte fungi (mould) and by candida
Tinea unguim is dermatophyte onychomycosis
dermatophytes cause 90% of onychomycosis

118
Q

T/F

>50% of nail dystrophy is due to onychomycosis

A

True

119
Q

T/F

Onychomycosis accounts for >50% of all nail disease

A

False

15-40%

120
Q

T/F

approx 15% of nail dystrophy in children is due to onychomycosis

A

True

121
Q

Risk factors for onychomycosis?

A

Male
Older age
Occlusive footwear
Repeated nail trauma
Genetic predisposition (T rubum in particular may be seen in AD pattern)
Other nail disease e.g. psoriasis
Co-morbidities – hyperhidrosis, diabetes(3x increase), PVD, HIV(often all nails), other immunosuppression

122
Q

T/F

The feet and nails should always be inspected when dermatophyte is found elsewhere on the body

A

True

even kids with tinea capitis - dont forget!

123
Q

T/F

Up to 2/3 of cases of tinea unguim of toenails also have tinea pedis

A

False

up to 1/3

124
Q

Which toenails are most commonly affected by tine unguim?

A

1st and 5th toenails most commonly affected

? Due to trauma from shoes

125
Q

What are the common cause if tinea unguim?

A

Mostly anthopophilic
T rubrum>T mentag var interdigitale>E floccosum
rarely microsporum

126
Q

T/F

Epidermophyton spp are geophilic

A

False
E floccosum is only member of the genus and it is anthropophilic
Both the geophilic dermatophytes are types of microsporum

127
Q

T/F

tinea unguim affects finger nails more than toe nails

A

False

toe nails more

128
Q

T/F

tinea unguim affects multiple nails more often than a single nail

A

True

129
Q

T/F

tinea unguim is always asymptomatic

A

False

Can cause discomfort and pain on walking, activity and when trimming nails

130
Q

What are the complications of tinea unguim?

A 
Tinea elsewhere – other nails (often), pedis (often), crura, manuum etc
Cellulitis
Osteomyelitis
gangrene e.g. diabetics, immunocompromised etc
Pseudomonas pyoderma
paronychia
Dermatophytid reaction
EAC
Urticaria
EN
Asthma/resp tract sensitization
Psychosocial effects, work discrimination, poor sex life
Damaged socks and stockings
131
Q

What are the clinical types of onychomycosis?

A 
DSTEP
Distal and/or lateral subungual (DLSO)
Superficial white (SWO) – 3 types
Total dystrophic onychomycosis (TDO)
Endonyx oychomycosis
Proximal subungual (PSO)
132
Q

T/F

Oral antifungals may be started based on a clinical diagnosis of tinea unguim

A

False
If positive fungal KOH prep in rooms can start systemic while awaiting culture. Otherwise should wait until results confirm fungus before starting oral antifungals

133
Q

T/F
samples of tinea infection from the skin are likely to culture the same organism that is infecting the nails in concurrent tinea unguim

A

True

134
Q

T/F

Distal and/or lateral subungual onychomycosis (DLSO) is the most common pattern of tinea unguim

A

True
can be any dermatophyte
Can also be caused by Scopulariopsis brevicaulis

135
Q

T/F

In Distal and/or lateral subungual onychomycosis (DLSO), the organism invades via hyponychium and progresses proximally

A

True
distal or lateral nailfold is point of infection
proximal progression is reason clippings often negative

136
Q

T/F
In Distal and/or lateral subungual onychomycosis (DLSO), there is often nail bed (subungual) hyperkeratosis, thick yellow nail plate & onycholysis

A

True

May progress to total nail dystrophy = total dystrophic onychomycosis (TDO)

137
Q

What are the 3 types of Superficial white onychomycosis (SWO)?

A

Discrete white patches
Diffuse white change
Transverse striate white bands

138
Q

T/F

Superficial white onychomycosis (SWO) is due to direct invasion of the dorsal nail plate

A

True

139
Q

T/F

Superficial white onychomycosis (SWO) is a more common type in children

A

True

140
Q

T/F

Superficial white onychomycosis (SWO) is only caused by dermatophytes

A

False
Esp T mentagrophytes var. interdigitale
also can be T. rubrum, tonsurans
Also Fusarium spp., Aspegillus spp., Acremonium, S, hyalinum, + S. dimidiatum (causes black discolouration of nail)

141
Q

T/F

Scytalidium dimidiatum can cause black version of Superficial white onychomycosis

A

True

142
Q

T/F

Superficial white onychomycosis (SWO) is more likely to respond to topicals than other types of onychomycosis

A

True

except if Transverse striate white bands

143
Q

T/F

Superficial white onychomycosis (SWO) with Diffuse white change is often resistant to topicals

A

False

Transverse striate white bands type is resistant to topicals

144
Q

T/F

Onychomycosis usually invovles both the nail bed and nail plate

A

True

except for endonyx onychomycosis - no real nailbed involvement

145
Q

T/F

In endonyx onychomycosis there is no real nailbed involvement so no onycholysis or subungual hyperkeratosis

A

True
Nail plate turns white
Can look like diffuse WSO or leukonychia

146
Q

T/F

total dystrophic onychomycosis (TDO) is the endpoint of other types of oncyhomycosis

A

True

147
Q

T/F

Promary total dystrophic onychomycosis (TDO) is more often Non-dermatophyte environmental fungi than dermatophytes

A

False

More often candida than dermatophyte

148
Q

T/F

In Proximal subungual (PSO) the organism invades under the proximal nailfold

A

True

149
Q

T/F

In Proximal subungual (PSO) always think of HIV/AIDS or other causes of immunosupression

A

True

150
Q 
T/F
Proximal subungual (PSO) is often caused by T mentagrophytes var. interdigitale
A

False

usually with T rubrum or non-dermatophyte fungi

151
Q

T/F

chronic paronychia or chronic mucocutaneous candidiasis predispose to candidal onychomycosis

A

True

Otherwise kids >3 and adults rarely get primary candidal nail disease

152
Q

T/F

Candida are common cause of onychomycosis in children under 3

A

True

153
Q

T/F

Non-dermatophyte fungi (mould) onychomycosis affects toenails more than finger nails

A

True

often only one nail, esp great toenail

154
Q

What makes you suspect Non-dermatophyte fungi (mould) onychomycosis?

A 
isolated nail
resistant to Rx
positive microscopy but neg culture
no tinea elsewhere
May be Hx of walking barefoot outdoors
155
Q

T/F

Dermatophytes are superficial mycoses and never cause invasice disease

A

False
Rarely dermatophytes can proliferate and become disseminated
Esp if immunocompromised and if chronic untreated tinea infection
T rubrum most commonly
Can cause ulcerating/draining dermal nodular lesions
Can also be tender nodules on extremeties
Rx is by surgical excision and systemic Rx – terbinafine, itraconazole, griseo, amphotericin B

156
Q

T/F

It is unecessary to retest hair/scalp samples after a course of treatment for tinea capitis

A

False
Must retest
mycological cure is the endpoint NOT clinical cure

157
Q

How long do fungal infcetions need to be treated for if using oral Rx?

A 
Depends on site and agent
Guide for terbinafine use;
1 wk for skin (corporis/faceii/cruris)
2-4 wks for manuum/pedis
4 wks for Capitis
6 wks for fingernails
12-16 wks for toenails
158
Q

What is the dose of terbinafine?

A 
250mg daily in adults (1 tablet)
Wt based dose in kids;
Under 20kg – 62.5mg/day (Qtr tab)
20-40kg – 125mg/day (Half tab)
40kg+ – adult dose
Can do pulsed therapy for tinea unguim;
500mg daily for 1 week per month for 3 mnths for fingernails and 4 mnths for toenails
159
Q

What is the dose of Griseofulvin for tinea capitis?

A

Adults 500mg-1g daily for 8-12 wks
Kids;
20mg/kg/day (up to 500mg) for 6-8 or even 12+ weeks
BAD guideline says if Wt >50kg should use 1g per day in single/divided dose
Same dose for other indications but last line agent as poor efficacy

160
Q

T/F

terbinafine is first line for tinea capitis unless M Canis cultured

A

True

Aus Ther guidelines 2015

161
Q

T/F

Fluconazole is weekly dosing except in tinea capitis as it accumulates in tissues

A

True

and rarely used in tinea capitis

162
Q

T/F

It is not necessary to use a topical agent in addtion to systemics for tinea capitis

A

False
use alternate day antifungal shampoo – Nizoral 2% or selenium sulphide 2.5% (selsun gold) - daily for first wk then alternate days
To reduce shedding of organisms

163
Q

T/F

Household contacts should be treated in cases fo tinea capitis

A

True
Examine all household contacts and treat if infected – esp if T tonsurans as highly infectious
Treat with systemic if clinical infection
Send samples in all cases even if clinically clear
If +ve treat with topical and retest – oral Rx if still +ve

164
Q

What cases of tinea unguim can be treated topically?

A

Topical monotherapy suitable for:
- Distal subungual onychomycosis if under 50% of nail and no matrix involvement
Or;
- White superficial onychomycosis

165
Q

What are topical treatments for tinea unguim?

A

Amorolfine 5% (Loceryl) nail lacquer once a week up to 12 months – effective in up to 50% of distal cases. Can prevent recurrence. Can cause itch, burning, redness
Miconazole (Daktarin) tincture
Bifonazole (Canestan) kit available with urea to lyse the nail – 6 wk treatment

166
Q

What general measures should be advised in cases of tinea unguim?

A

Breathable footwear and cotton socks
Avoid/discard/wash old thongs/sandals etc
Can put naphthalene mothballs in shoes and tie up in plastic bag for 3 days
Keep feet clean and dry
Use antifungal or absorbent powder
Keep nails trimmed short and free of undernail debris, don’t share clippers
Treat household members if infected/ clean damp areas/ avoid locker-rooms, swimming etc

167
Q

How can tinea unguim treatment be monitored?

A

After a few months should see normal nail growing through from prox fold. Make a mark w/ scalpel for pt to watch. If dystrophy stays distal until all grown out then cured. Need to retreat if dystrophy progresses proximal to mark

168
Q

What can be done for tinea unguim if topical and systemic Rx failed?

A

Chemical or surgical destruction/removal of the nail followed by topical treatment
some reports of success with lasers or PDT but not standard care

169
Q

How is mould-onychomycosis treated?

A

can use terbinafine or itraconazole but may be better cure rate from surgical avulsion + topical Rx

170
Q

T/F

terbinafine has a 70-80% cure rate for tinea unguim

A

True

terbinafine is first line in adults and kids

171
Q

T/F

Itraconazole has a 50% cure rate for tinea unguim

A

False
Both Itra and Flu -conazole have 70% cure rates
Itraconazole second line after terbinafine (but most expensive)

172
Q

T/F
Tinea manum and moccasin tinea pedis can be significantly hyperkeratotic and should be considered in DD for acquired palmar/plantar keratodermas

A

True

173
Q

What are risk factors for candidal infections?

A 
Antibiotic use
Diabetes
Xerostomia
Local or systemic steroid use
Occlusion
Hyperhidrosis
Immunosuppression inc HIV
174
Q

What are particular risk factors for candidal angular cheilitis?

A 
Overlap of skin at angles – if no teeth or elderly
Dentures/braces etc
Drooling
Eczema
B12 deficiency
175
Q

What are the types of candidal oral infection?

A

Pseudomembranous form (thrush) – thick white exudate
Chronic atrophic form – patch of erythema
Chronic hyperplastic form – adherent white plaques
Glossitis – painful inflammation/atrophy of dorsal surface of tongue
Denture stomatitis
Angular cheilitis (perleche)

176
Q

What is the cause of erosio interdigitalis blastomycetica ?

A

Candidal web space infection

177
Q

T/F
erosio interdigitalis blastomycetica is particularly likely to affect the webspace between the 2nd and 3rd fingers in those doing wet work

A

False

between 3rd & 4th digits most likely

178
Q

T/F

granuloma gluteale infantum is caused by candida

A

False
Complication of primary irritant napkin dermatitis
But candidal napkin infection can look quite red and juicy so is DD

179
Q

What are the types of candidal onychomycosis?

A

4 types;

  1. Chronic paroncyhia with secondary nail dystrophy
    - Wet work or thumb-sucking children
  2. Distal nail infection - Uncommon, often on steroid Rx or have Raynaud’s
  3. Total dystrophic onychomycosis
    - due to chronic mucocutaneous candidiasis
    - gross thickening and hyperkeratosis
  4. Secondary candidosis - in ps with tinea unguim or psoriatic nail disease etc
180
Q

What are the KOH prep findings of candida spp?

A

budding yeast and pseudohyphae

181
Q

T/F

Itraconzole is first line for candidal onychomycosis

A

True
azoles work best
4 wks for fingernails, 12 wks for toenails

182
Q

T/F

It is important to address risk factors when treating candida infections

A 
True
Eg.
check for diabetes
r/o B12 def in perleche
Treat hyperhidrosis, xerostomia, drooling, eczema etc
183
Q

What is Chronic mucocutaneous candidiasis?

How is it treated?

A

Resistant chronic candidosis of infection of skin, nails and mucosae
usually associated with immunodeficiencies
Need high dose systemic therapy - fluconazole;
400-800mg OD for 4-6 months (eradication)
Then 200mg daily (suppression)
Must monitor LFTs closely

184
Q

T/F

Candida spp live in gut

A

True
Increased numbers if had course of antibiotics
- can trigger napkin candidiasis in infants

185
Q

Which immunodeficiencies are associated with recurrent/resistant candida or Chronic mucocutaneous candidiasis?

A 
SCID
HyperIgE syndrome esp STAT3 (Job) and PGM3 types (less in DOCK8)
APECED
Autoimmune polyendocrinopathy type 1
MST1 deficiency disease
Also Mucocutaneous candidiasis can be an immunodeficiency syndrome in itself with AD or AR inheritnece and various mutations described e.g. 
STAT1 gain of function mut
Dectin1 mut
CARD9 def
IL-17 RA def
IL-17F def
ACT1 def
186
Q

What is the organism responsible for Sporotrichosis?

A

Sporothrix schenckii
dimorphic fungus (can exist as mold/hyphal/filamentous form or as yeast)
present in soil worldwide

187
Q

How is Sporotrichosis acquired?

A

Classically acquired from cutaneous inoculation e.g. via a prick from a rose thorn also orchids
Can also be carried by cats in skin ulcers and transmitted to humans (esp in Rio de Janeiro)
Can be multiple inoculation sites simultaneously
several wks incubation time

188
Q

T/F

After innoculation by Sporothrix schenckii disease presentation depends on host factors

A

True
If no existing immunity to S. schenckii infection spreads to local nodes
If existing immunity no spread – forms a fixed ulcer or plaque
If immunocompromised can develop extensive cutaneous disease +/- systemic disease

189
Q

How does Sporothrix schenckii spread to local LNs?

A

sporotrichoid spread over several weeks
starts as painless papule at innocualtion site - ulcerated and becomes purulent
Involved lymphatics become fibrosed - need to diagnose and treat early

190
Q

What is histo of Sporotrichosis?

A

Suppurative and granulomatous inflammation in dermis and subcutis
Asteroid bodies often seen + may have may have Splendore-Hoeppli phenomenon
Yeast forms are cigar-shaped - hard to until stained; PAS or GMS

191
Q

Which fungal infections may have Splendore-Hoeppli phenomenon on histo?

A

sporotrichosis, pityrosporum folliculitis, zygomycosis, candidiasis, aspergillosis and blastomycosis

192
Q

T/F

Sporothrix schenckii will grow in different forms at either 25 or 37 degrees

A

True

193
Q

What is treatment of Sporotrichosis?

A

Itraconazole 100-200mg daily for 3-6 months
Amphotericin B if severe disseminated disease
KI (saturated solution of potassium iodide – SSKI) has been used

194
Q

What is Chromoblastomycosis?

A

slow growing verrucous plaque on an extremity
caused by one of several types of dematiaceous (pigmented) fungi
Characterised by histological finding of Medlar bodies (copper pennies) - round pigmented bodies
Most common in tropical / sub-tropical climates

195
Q

What organisms cause Chromoblastomycosis?

A

Fonsy Cuddles Philippa
Fonsacea spp
Cladophialophora (Cladosporium) carrionii
Phialophora verrucosa
found in soil and decaying plants and wood

196
Q

T/F

Chromoblastomycosis frequently ulcerates

A

False

Does not ulcerate

197
Q

T/F

Chromoblastomycosis may have central resolution resulting in a annular lesion

A 
True
Usually a varrucous or granulomatous-looking plaque
Can be annnular
can be subcutaneous mass
No constitutional symptoms
198
Q

What is histo of Chromoblastomycosis?

A

Suppurative and granulomatous inflammation in dermis
– neuts, histiocytes, plasma cells, multinucleated giant cells
Pseudoepitheliomatous hyperplasia + intraepidermal abscesses
pathognomonic Medlar bodies (copper pennies) are round pigmented bodies found in histiocytes/giant cells and in interstitium in clusters or chains
May also see hyphae but unusual

199
Q

How is Chromoblastomycosis treated?

A

Difficult to treat – involve ID specialist
Can excise small lesions + oral antifungals
Itraconazole 200mg/day for at least 6 months – cure in 80-90%
Terbinafine 250mg/day for at least 7 months 2nd line
Heat and cryosurgery have been used
Antibiotics if secondary bacterial infection

200
Q

What is Phaeohyphomycosis?

A

Infection caused by any one of a group of demitaceous fungi which produce brown-black hyphae (due to melanin in cell wall) seen in the tissue sections
found in plants and soil
Can be considered a ‘subcutaneous’ mycosis and an opportunistic infection

201
Q

What fungi cause Phaeohyphomycosis?

A 
ABC most common;
Alternaria, Bipolaris or Curvularia Spp
Also;
Exophiala jeanselmei and E. dermatitidis.
Exserohilum or Phialophora spp
202
Q 
T/F
Organisms responsible for Phaeohyphomycosis can cause infections classiifed as
o	Superficial 
o	Cutaneous
o	Subcutaneous
o	Systemic
A

True

203
Q

T/F

men have higher risk of Phaeohyphomycosis if outdoor work/activities

A

True

men more often affected

204
Q

T/F

implanted material e.g. splinter is ofetn seen in histo of Phaeohyphomycosis

A

True

205
Q

T/F

Pigmented hyphae in the dermis/subcutis are characterisitic of subcutaneous Phaeohyphomycosis

A

True
But are seen in the SC in superficial forms - tinea nigra and black piedra
and in SC/upper epi/nail in cutaneous forms - Scytalidium dimidiatum or S. hyalineum causing infection of palms, soles (moccasin type) or interdigital spaces or onychomycosis mimicking dermatophytosis

206
Q

What is treatment of subcuatneous Phaeohyphomycosis?

A

excise completely if possible

6-12 months itraconazole for extensive localised or systemic disease

207
Q

T/F

cutaneous cryptococcosis causes lesions resembling keloid scars

A

False
Lobomycosis does this
seen in Central and S America

208
Q

T/F

chains of thick-walled yeast-like cells – ‘brass knuckles’ are characteristic feature of histo of Lobomycosis

A

True

209
Q

What causes cryptococcosis? How is it acquired?

A

encapsulated yeast Cryptococcus neoformans
found in bird droppings (pigeons)
Most common disease is primary lung infection which disseminates to CNS, bones and skin(15%)
Primary cutaneous cryptococcosis can occur by direct inoculation but is very unusual and systemic disease needs to be ruled out

210
Q

T/F

extra-pulmonary Cryptococcus is AIDS-defining illness

A

True

disease is mainly seen in setting of AIDS

211
Q

T/F

cutaneous cryptococcosis can be treated with itraconazole

A

True

Must r/o HIV and assess for systemic disease - CT chest, MRI brain, bone scan

212
Q

What is Mycetoma?

A

AKA Madura foot
Granulomatous infection of dermis and subcutis which forms draining sinuses containing characteristic grains called sulphur granules or sclerotia

213
Q

What are the types of Mycetoma?

A

Actinomycotic mycetoma – caused by actinomycetes; esp Central & S America
Eumycotic mycetoma – caused by true fungi; esp Africa
Botryomycotic mycetoma – caused by true bacteria (rare)

214
Q

What organisms cause Eumycotic mycetoma?

A

Madurella spp., Pseudallescheria boydii, acremonium spp., Fusarium spp

215
Q

What is the management of Eumycotic mycetoma?

A

Must excise en mass with large margin of normal tissue before bone becomes involved
Then use systemic antifungal Rx for long period
NB bacterial types can usually be treated with long term antibiotics only

216
Q

What are the categories of systemic mycoses?

A

endemic mycoses (true pathogens) and opportunistic systemic mycoses

217
Q

What are the dimorphic fungi?

What disease do they cause?

A 
can exist as mold/hyphal/filamentous form or as yeast;
Sporothrix schenckii (sporotrichosis)
Histoplasma capsulatum var. capsulatum (histoplasmosis)
Blastomyces dermatitidis (blastomycosis)
Coccidioides immitis (Coccidiomycosis)
Paracoccidioides brasiliensis (Paracoccidiomycosis)

All except Sporothrix schenckii (sporotrichosis) are endemic systemic mycoses. S schenckii is in the subcutaneous mycoses group

218
Q

T/F

Dimorphic fungi can change between mould and yeast forms which help them evade the immune system

A

True

219
Q

T/F

Endemic mycoses most often cause pulmonary disease through inhalation of conidia

A

True
Skin lesions can be primary through traumatic inoculation into the skin or secondary from dissemination of disease which has originated elsewhere in the body (usually pulmonary)

220
Q

Where is Histoplasma capsulatum found?

A

In soil in warm climates. Africa + C & S America

Carried by birds and bats + in their feaces – caves, chicken coops, old buildings etc

221
Q

T/F

Endemic mycoses can cause EN

A

True

esp Coccidiomycosis

222
Q

T/F

There are 4 patterns of skin manifestation of disseminated Coccidiomycosis

A

True

  1. Papule, pustule, plaques, abscesses esp on face
  2. Ulcers
  3. Diffuse macular eruption (toxic erythema)
  4. Hypersens rcn- EM, EN
223
Q

T/F

Endemic mycoses are mainly found in soil in Central and South America

A

True
Blastomyces dermatitidis most widespread; Eastern USA & Canada. Africa, India
Only Histoplasmosis is found in Australia

224
Q

T/F

Histoplasma spp is found in Australia and infections (histoplasmosis) have been reported from most states

A

True

esp in caves where bats live

225
Q

T/F

Tissue samples sent for culture for suspected Endemic mycoses should be cultured at 32 and 37 degrees

A

False
25+37˚C
Can do PCR on tissue for histoplasmosis
NB Sporothrix schenckii isolates grow best at 35 degrees

226
Q

T/F

IV amphotericin B and/or iraconazole are the treatment for Endemic mycoses

A

True

227
Q

T/F

Localised skin Sporotrichosis responds well to potassium iodide

A

True

4-6 ml three times a day for 2-4 months

228
Q

T/F

Oral ulcers are seen in systemic histoplasmosis

A

True

229
Q

What are skin findings of histoplasmosis

A

Non-specific cutaneous nodules or vegetative plaques

Pathology shows Intracellular yeast with rim of clearing (in histiocytes & giant cells)

230
Q

T/F

A serology test is available for histoplasmosis

A

True

can alos do PCR on blood for disseminated disease

231
Q

T/F

Amphotericin B active against all opportunistic fungal pathogens

A

True

Voriconazole also works well but not for zygomycosis

232
Q

T/F

All dimorphic fungi can cause sporotrichoid spread

A

True

233
Q

T/F

some opportunisitc fungi and those that cause phaeohyphomycosis can cause lesions with sporotrichoid spread

A

True

e.g Fusarium spp., Alternaria spp

234
Q

T/F
examples of opportunisitic fungal pathogens include
Aspergillus spp
Zygomycosis (Rhizomucor spp., Rhizopus spp., Absidia spp.)
Hyalohyphomycosis; Fusarium (fusariosis), Penicillium, paecilomyces
Trichosporon spp.
Penicillium marneffei
Pneumocystis jirovecuii (PCP)
and candida spp

A

True

The endemic mycoses pathogens and those causing Phaeohyphomycosis are often also considered opportunisitic

Medical dermatology Dan (41 decks)

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