Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Dermatology Pathology > Superficial Fungal Skin infections > Flashcards

Superficial Fungal Skin infections Flashcards

You may prefer our related Brainscape-certified flashcards:
Dermatology Board Prep flashcards
1
Q

What is a Dermatophyte?
• where does it live?
• 3 important genera?

A

Dermatophyte is aka tinea/ringworm these live in soil and on animals and humans and digest keratin and invade hair, skin, and nails.
3 primary genera:
• Trichophyton
• Microsporum
• Epidermophyton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Is Candidiasis a dermatophyte?
• what type of fungal infection does it cause ?

A

NO is a yeast, causes tinea vericolor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Tinea Capitis
• who will typically present to you with this?
• Symptoms?
• Two most common causes?

A

Tinear capitus is most common in children 3-7 years old these kinds may have some alopecia and posterior cervical or sub-occipital LAD and is pretty prevalent with 3-8% of this population being affected.

2 fungi responsible:
• Trichophyton tonsurans (90% in US)
• Microsporum canis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do these 3-7 years olds walking around with tinea capitius contract these infections?
• where do you expect these kids come from?
• Bugs responsible?

A

These kids are 3-7 and typically come from large families, crowded living conditions, or are of low socioeconomic status. Trichophyton tonsurans and Microsporum canis are transmitted by animals, soil, people (some of which may be ASYMPTOMATIC CARRIERS). Fomites live on anything you put near your head.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 2 versions tinea capitis may present in (regardless of cause)?
• what do you need to do regardless of whether the lesions are ambiguous or seemingly clear cut?

A

Seborrheic Dermatitis (left) - may look like dandruff but CULTURE IT
Localized plaques
***CULTURE THESE - moisten the tip of a swab and srub vigerously***

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What patterns might you catch Trichophyton tonsurans or microsporum canis growing on on your head?

A
  • Scaling
  • Patchy
  • Block Dot Pattern
  • Pustules
  • Kerions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why do you see a broken hair shaft (black dot pattern) in some people with tinea capitus?
• will a woods lamp be positive in these people?

A
  • Trichophyon tonsaurus likes to grow in hair shafts causing them to die and break off
  • Woods lamp (UV light) is useless in finding tinea capitus these days
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What complications may result from allowing a Kerion to persist?

A

• permanent hair loss and scarring may be the result.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Someone has tinea capitus and you see fungi on KOH. Should you still culture?

A

YES, you must culture. This double confirms that its a fungus and also tells you what kind you’re dealing with.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What disease might mimic tinea capitus?

A

Seborrheic Dermatitis
Psoriasis
Alopecia Areata

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is seborrheic Dermatitis?
• who gets it? who doesn’t?

A

Seborrheic Dermatitis is a diffuse dryness, oily, or white/yellow scale on the scalp.

• This is ONLY found in infancy and after Puberty - anytime between then think TINEA CAPITUS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are some features that can help you differentiate tinea capitus and psoriasis?
• what about differentiating it from Alopecia Areata?

A

Psoriasis:
•Erythematous plaques with silvery scale

•Favors postauricular and posterior hairline

Alopecia Areata
• Well-circumscribed smooth bald patches
(NO BROKEN HAIRS or redness like with trychophyton t.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do you treat tinea capitis?
• how does your treatment depend on cultures?
• how should the medicine be ingested?

A
  • MUST USE a systemic antifungal like GRISEOFULIVIN + Ketoconazole/Selenium Sulfide shampoo to penetrate the hair follicle (a topical agent alone will not work)
  • If its M. canis you need a higher dose

• Take it with a FATTY FOOD to enhance absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why does treating patients with Terbinafine suck?

A

You have to get baseline ALT/ASTs and you need to do routine CBC monitoring for immunodeficient pts.
*Its also not very effective against M. canis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What should you consider adding to your therapy if your patient with tinea capitus presents with a Kerion?

A

SYSTEMIC STERIODS may be indicated along with the griseofulvin and ketoconazole hair wash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Tinea Corporis
• what organism is the typical culprit? how is it transmitted?
• how does this change based on age?
• How does it appear?

A

Tinea Corporis may occur after contact with an infected person or animal. People will present with one or more well defined anular SCALY erythematous PLAQUES with central clearing and a scaly, vesicular, papular, or pustular border.

Kids:
M. canis > M. audouinii, T. mentagrophytes

Older kids/Adults:
T. rubum, T. verrucosum, T. mentagrophytes, T. tonsurans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

You have a child that presents with a well defined annular scaly, erythematous plaques that have a central clearing and a scaly, vesicular, papular, or pustular border. Culture shows that its positive for T. rubrum. How did it get there?

A

T. rubum in young children is likely the result of an adult transmitting the fungus to the child.
Remember.

Kids:
M. canis > M. audouinii, T. mentagrophytes

Older kids/Adults:
T. rubum, T. verrucosum, T. mentagrophytes, T. tonsurans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

A patient has been treating there itchy skin with topical steriods for several weeks and the inflammation is reduced but the scaly ring shaped lesion still persists. What has happened?

A

Steriods may reduce inflammation of tinea corporus making it more difficult to see

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is Majocchi’s Granuloma?
• how will therapy differ for this variant of tinea corporus?

A

This is granulomatous folliculitis that causes erythematous plaques or patches studded with nodules to form - this is the result of the fungi getting into the hair follicles and causing a foriegn body reaction

**You’ll need to treat Majocchi’s with systemic drugs**

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How can you diagnose tinea corpora?

A

Clinical presentation or KOH prep may be diagnostic but FUNGAL CULTURE is still highly recommended

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are some things that you might confuse tinea corpora with?
• how can you rule them out?

A

Nummular Atopic Dermatitis
• This is NOT annular and MORE itchy than tinea c.

Psoriasis
• This is dull pink with silvery, white scale and nummular lesion
• Typically distributed in HIGH PRESSURE areas

Granuloma Annulare
• Most confusing ddx. no scale, rubbery rim
• LOCATION is the best way to get a clue DORSAL hands, Wrists, Feet and Ankles are typical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the treatment of tinea corpora?
• special cases?

A
  • 2-4 weeks of topical therapy
  • Reasses dx. or switch to oral medication if it doesn’t resolve

SYSTEMIC THERAPY REQUIRED FOR:
• Immunocompromised Hosts
• Majocchi’s
• tinea faciei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What indication is there for used a topical corticosteroid + fungal product in treatment of something like tinea corpora?

A

NO USE EVER FOR THESE - they often cause persistent or worsening infection and steriods may cause skin atrophy etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Tinea Mannum
• Who typically presents with this?
• What is the cause?

A

Tinea manuum (fungal infection of skin on hands) will most commonly present in a man with a SINGLE HAND that has red/scaly/chronically dry palm T. rubum, T. mentagrphytes, or E. floccosum being the culprit. THIS IS RARE IN CHILDREN.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What two patterns can Tinea mannum take on?
• how do you diagnose this?

A

Palmar: fine scale, may be unilateral
Dorsal: annular, red, and scaly

Dx; NOT clinical, you need KOH prep or FUNGAL Cx.

26
Q

Tinea Mannum DDx

A

Other Dermatitis
• Irritant or Contact - get this from hx.
• Psoriasis - silver scale, bilateral

27
Q

How does treatment for Tinea Mannum differ on the basis of the subtype?

A

Palmar: REQUIRES ORAL ANTIFUGAL (makes sense, it’d be hard to keep a cream on your palms)

Dorsal: Topical Antifungal would be fine

28
Q

Tinea Cruris
• what is this?
• who typically presents with this?
• Risk factors for getting it?

A

JOCK ITCH more frequently occurs in men than women. He will have itchy, red, annular, scaly plaques over the groin and medial thighs. Men at the greatest risk are obese, hot, and humid.

29
Q

What fungi are most typically responsible for Tinea Cruris?

A

T. rubrum, T. menatgrophytes, E. floccosum

30
Q

How do you diagnose tinea cruris?

A

KOH
Culture

31
Q

What should be in your differential for Tinea Cruris?
• how do you rule it out?

A

DDx:
Candidiasis
• Satellite pustules and candidiasis is typically MORE RED

Erythrasma (Rare)
• No Scale and has CORAL fluorescence

***As with most of these diseases you need to rule out psoriasis and seborrheic dermatitis as a cause***

32
Q

Tinea Cruris
• how do you treat it?

A

Topical Antifungals often powders are helpful

• can use oral therapy if severe or refractory

33
Q

Tinea pedis
• who gets it?
• what puts you at increased risk?

A

typically tinea pedis occurs in MEN (10% of world population has this). Men who wear occlusive shoes, or use communal pools/showers are at an even higher risk. Typically, this presents as itching, sacling on soles, between toes, or blistering.

34
Q

Tinea Pedis
• how does the probable etiologic agent change with location?

A

Moccasin Distribution:
• Fine Dry scale over soles => T. rubrum

Vesiculobullous:
• Vesicles/Bullae on soles, especially insteps => T. mentagrophytes

35
Q

How do you diagnose Tinea Pedis?

A

KOH
Fungal Culture

36
Q

What is in your differntial for tinea Pedis?
• what helps to rule it out?

A

Contact Dermatitis
• Typically affects the dorsal feet (but may mimic the mocassin pattern)

Dyshidrotic Eczema:
• Tapioca Vesicles that are INSANELY ITCHY (hard to tell the diff. this is why we culture)

37
Q

Tinea Unguinum (onychomycosis)
• who is typically affected?
• Risk factors?

A

Nail infections often present as discoloration, thickening, onycholysis in MALES (60% of men over 70 are affected).

Risk Factors;
• Diabetes, HIV, Poor Circulation, trauma, dystrophy

38
Q

Tinea Unguinum (onychomycosis)

A

Bug Responsible:
• T. rubrum, T. mentagrophytes, E. Floccosum as well as som non-dermatophyte molds or yeasts could be responsible

39
Q

What 4 patterns does Tinea Unguinum (onychomycosis) occur in?

A

4 patterns:

  • Distal Subungual
  • Proximal Subungual
  • White Superficial
  • Candida
40
Q

Tinea unguium
• what is the most common pattern?
• Contrast this with the proximal subungual pattern?

A

Distal subungual from tip of nail to cuticle is most common.
If you see PROXIMAL SUBUNGUAL then your patient has AIDS (or is HIV positive)

**This is almost as pathognomonic as the trash stache**

41
Q

Tinea Unguium
• what does it look like?

A

White Superficial plaques on the dorsal nail plate

42
Q

How does Candida present differently than proximal, distal, or white tinea unguinum?

A

Candida is typically VERY RED and is often associated with kids who suck on their fingers.

43
Q

What is Chronic Paronychia?
• what causes it?

A

Chronic Paronychia is Nail Dsytrophy associated often with Candida Albicans (think kids sucking on their thumb)

44
Q

What is Trachyonychia?
• what does it look like?
• what causes it?

A
45
Q

What causes Beau’s lines?
• what disease association should you make with this?

A

KIDS OFTEN GET THIS FOLLOWING HAND/FOOT/MOUTH disease

46
Q

How does phyisical trauma to the nail most often present?

A
47
Q

What is Habit Tic Deformity?

A
48
Q

How do you make the dx of Tinea Unguium?

A
49
Q

T or F: most nail fungal infections are treated systemically.

A

True - topicals are not very effective.

need TERBINAFINE for 6wks for fingernails and 12 weeks for toenails

50
Q

HOW LONG DOES IT TAKE A FINGERNALE TO GROW OUT?
• TOENAIL?

A

Fingernail
• 4 to 6 months to grow

Toenails
• 12 to 18 months to grow

51
Q

Tinea Versicolor
• What pathogens are often indicated?

A

Often yeast forms of the dimorphic fungus Malassezia furfur (piryrosporum orbiculare, pityrosporum ovale) are responsible fro the infection)

52
Q

Tinea Versicolor
• Who typically gets this and how does it present?
• where on the body is it found?
• When do they typically present?

A

Often this presents during summer in adolescence as multiple scaling, oval macules, patches, and thin plaques over the upper trunk, proximal arms, and sometimes the face and neck.

53
Q

How does the specific presentation of tinea versicolor vary with skin tone?
• What agent causes this?
• what fungi cause this?

A

Azelaic Acid production by Malassezia furfur, Pityrosporum orbiculare, Pityrosporum ovale produces hypopigmentation in people with darker skin tone and hyperpigmentaion (red) in people with lighter skin tone.

54
Q

What another name for tinea versicolor?

A

Pityriasis versicolor

55
Q

What conditions should be in your differential for Tinea Versicolor?
• how do you rule this out?

A

Pityriasis alba is a hypopigmenation issue that often results from dry skin and irritation. It becomes apparent when you you get tan because the affected area does not tan.

••Its often less extensive than Tinea Versicolor**

56
Q

Tinea Versicolor
• how do you diagnose?
• Tx

A

Diagnosis with KOH - you are looking for SPAGETTI and MEATBALLS appearance.

Tx: Topical Therapy + education

Topicals to use: Selenium sulfide / Ketoconazole

Severe dz: use Ketoconazole systemi + topical

57
Q

What are some fungal skin infections caused by Candidiasis?

A

Intertriginous
Paronychia
Angular Cheilitis

58
Q

Angular Cheilitis
• where occur?
• how does it present?

A

Angular Cheiltis presents in the oral commisures and is common in the elderly (dentures), lip lickers. Presents as painful fissures at the edges of the mouth with small pustules.

59
Q

Angular Chelitis
• how do you treat?

A

Tx:

  • Topical anti-yeast cream
  • Decrease moisture
60
Q
A

Dermatology Pathology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions