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Clinical 1 > Cutaneous Fungal Infections > Flashcards

Cutaneous Fungal Infections Flashcards

1
Q

What are the two common types of cutaneous fungal infections?

A

Dermatophytes

Yeast

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2
Q

What are the 5 types of dermatophyte infections?

A 
Tinea corpis (ringworm of the body)
Tinea cruris aka jock itch (ringworm of the groin)
Tinea pedis aka athlete's foot
Tinea capitis (scalp)
Tinea unguium (toenails)
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3
Q

What are the 2 types of yeast infections?

A 
Cuteaneous candidiasis (occurs in intertriginous areas such as the groin, axillae, interdigital spaces, under the breasts)
Pityriasis versicolor (previously classified as "tinea"; best to refer is causation is unclear)
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4
Q

What are the objectives of self-treatment?

A

Provide symptomatic relief (itching, burning and other discomforts)
Eradicate existing infection (inhibit fungal growth
Prevent future recurrent infections
Refer is infection is widespread, systemic, recurrent or persistent

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5
Q

What are the over the counter products available?

A

Clotrimazole 1% or Miconazole 2%
Tolnaftate 1%
Undecylenic Acid (Desenex/ Fungicide liquid)
Nystatin 100 000 units/g

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6
Q

Describe clotrimazole 1% and micronazole 2%. What is the MOA? What is the dose? What are the adverse effects?

A

They are from the same family: imidazoles or azoles
They are fungistatic with a broad spectrum of activity
They are effective in treatment of dermatophyte and yeast infections
Dose: apply a thin layer morning and evening
Adverse effects: local skin irritation or hypersensitivity (burning, erythema, pruritus, rash, stinging)
Effects are seen in 1 to 2 weeks (pruritus should be cleared in 1 week)
OTC preparations are currently available in Canada: clotrimazole 1% cream (Canesten and generics), miconazole nitrate 2% cream, spray and powder (Micatin and genertics)

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7
Q

Describe Tolnaftate 1%. What are the brand names? What its the dose? What are the adverse effects?

A

It’s a thiocarbamate
Brand names: tinactin, zeasorb, Dr. Scholl’s, fungicure gel and generics
Available as a cream, gel, aerosol, topical powder, topical solution
Narrow spectrum antifungal; it is effective for the treatment of dermatophyte infections but ineffective for cutaneous candidiasis
Dose: apply morning and evening
Adverse effects: local skin irritation
Effects seen in over 2 weeks

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8
Q

Describe undecylenic acid

A

Available an ointment, powder or spray
Effective in treatment of dermatophyte infections
Ineffective in treatment of cutaneous candidiasis
Dose: apply twice daily
Adverse effects: itching, burning, stinging

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9
Q

Describe nystatin 100 000 units/g

A

It’s a polyene
Fungistatic or fungicidal (depends on organism)
Available as a cream or ointment
Effective for candidate infections
Ineffective in treatment of dermatophyte infections
Dose: apply two or three times daily
Adverse effects: rarely irritation

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10
Q

What are the prescription products available?

A 
Topical ciclopirox
Terbinafine
Topical terbinafine
Oral terbinafine
Ketoconazole
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11
Q

Describe topical ciclopirox (spectrum, adverse effects, dose, monitoring)

A

Broad spectrum agent: antimycotic agent effective against dermatophytes yeast and some bacteria
Adverse effects: pruritis, burning, erythema
Dose: apply to affected area twice daily for 4 weeks
After first week of treatment, relief from itching and other symptoms should occur
If after week 2 weeks, there is no clinical improvement, re-evaluate diagnosis

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12
Q

What are the topical ciclopirox products available?

A

Loprox 1% cream or lotion (for all tines and candida infections not responding to OTC therapy)
Stieprox 1.5% shampoo (used 2-3 times per week, fungal infections associated with seborrheic dermatitis)
Penlac 8% nail lacquer (only topical nail anti fungal avialable ont he market that is relatively effective

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13
Q

Describe terbinafine (spectrum, formulations)

A

Allylamine
Broad spectrum fungicidal agent
Fungicidal to dermatophytes but only fungistatic to candida
Available formulations: oral tablet, cream or spray

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14
Q

Describe topical terbinafine (dose, adverse effects)

A

Generally shorter treatment regimens, has a residual effect
Results in slightly higher cure rate than other topical options
Dose: apply to affected area once daily for 1 week
Adverse effects: pruritus, irritation/burning, rash, dryness
After terbinafine is topically applies, it has a half-life of 27 hours and less than 5% is absorbed

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15
Q

Describe oral terbinafine (products, metabolism, adverse effects)

A

Terbinafine (Lamisil and generics)
It is useful for fungal nail infections, or severe tinea skin infections that have failed with topical treatment
Hepatic metabolism: tablets may interfere with cytochrome P450 (creams and sprays have not shown this effect)
Adverse effects: headache, GI disturbances, hepatic failure, rash

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16
Q

Describe ketoconazole (spectrum, formulations, safety)

A

Imidazole
Broad-spectrum
Prescription products include cream and oral tablets
Oral dosage: risk of potentially fatal liver toxicity and therefore should only be used for serious or life threatening systemic fungal infections

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17
Q

What are dermatophytes?

A

Generally refers to the various Tinea infections

Commonly referred to as “ringworm” infection

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18
Q

Describe a dermatophyte infection

A

As it grows, it spread out in a circle
The inner skin appears healthy (section of clearing)
The outer ring is inflamed, red and scaly
The appearance of the circular lesion gives the appearance that a worm is circling beneath the skin

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19
Q

Can dermatophytes cause systemic infection?

A

No. They will only infect the upper layer of skin. They do not disseminate into the blood stream. They need the keratin in the epidermal layer

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20
Q

What are characteristics of dermatophytes?

A

Requires keratin for growth and proliferation (keratin is found in the cornified human epidermis stratum corneum)
Restricted to scalp, nails and superficial skin

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21
Q

How are dermatophyte infections spread?

A

Person to person contact (anthropophilic organism; generally mild reaction)
Soil to human (geophilic organism; generally more acute inflammation)
Animal to human (zoophilic organism; generally more acute inflammation)
Indirectly from fomites (i.e., furniture, hairbrushes, hats)

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22
Q

What are the most common dermatophyte pathogens in skin infections?

A

Trichophyton
Microsporum
Epidermophyton

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23
Q

In who do we most commonly see tinea corpis infections? What are common risk factors?

A

Most commonly seen in pre-pubescent individuals (children in daycares and schools)
Common risk factors: exposure to contaminated soils, exposure to infected animals or people (daycare), warm and most environments (showers and pools), shared towels or clothing

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24
Q

What are the signs and symptoms of tinea corpus?

A

Affected areas: often occurs on the skin of the trunk, face and extremities
Presentation: oval, annular (ring-like), erythematous, scaly patches. Reddened edges, and sharp margins (abrupt transition from abnormal to normal skin), inner area is clear
Itching is variable depending on patient

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25
Q

How do you differentiate ring worm of the body from other cutaneous conditions (eczema, psoriasis, contact dermatitis, bacterial skin infections)?

A

Clearning in the centre
Clear, sharp edges
Psoriasis has silvery plaques; here scaling is fain with small skin pieces
Contact dermatitis is typically less circular
Location: fungal infections occur in areas that collect excess moisture, contact dermatitis and bacteria skin infections is anywhere

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26
Q

What are the signs and symptoms that differentiate fungal skin infections from contact dermatitis and bacterial skin infections (e.g., impetigo)

A

Fungal skin infection may be wet/soggy, malodorous, thicker skin, rash, redness, scaling, round, inflamed, cracks/fissures
Contact dermatitis presents as lesions from raised wheals to fluid filled vesicles
Bacterial skin infections present as lesions or ulcers, may be red with pustules, may be warm to the touch, may have a foul door, coloured yellow/green discharge

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27
Q

When should a patient be referred?

A

Patients experiencing an infection with unclear aetiology
Immunocompromised patientss (e.g., immunosuppresants, uncontrolled diabetes, AIDS)
Experiencing tinea capitis, tinea barbae or tinea unguinium for systemic therapy
Responding poorly or are intolerant to topical therapy
Experiencing excessive, disabling, multifocal or inflammatory disease
Widespread
Affecting daily life

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28
Q

How do we manage tinea corpis?

A

Prevention: use general non-drug measures
Topical antifungal (OTC): imidazoles are first line of treatment, BID for 4 weeks (AM and HS), apply to normal skin 2 cm beyond the affected area
Symptoms should improve after one week. The area should be clear after second week. Continue to apply for at least a week
Tolnaftate and undecylenic acid are also options
Refractory or resistant cases: allylamines or oral agents

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29
Q

Describe tinea cruris

A

Affected areas are bilateral thighs (upper), ingunial folds (groin), buttocks, gluteal (anal) cleft (less common)
Scrotum and penis are usually spared
Can affect external vaginal area in females (but less common
If the scrotum, penis or internal vaginal area are involved, suspect cutaneous (or vaginal) candidiasis

30
Q

What are risk factors for tinea cruris

A

Warm and humid condition or increased sweating
Wearing wet or multiple layers of clothes
Immunocomprised individuals (atopic individual, AIDS)
Obesity
Prevalence is greater in men than in women (rarely affects children)

31
Q

Can one partner transmit tinea cruris infection to another?

A

Yes

32
Q

What are the signs and symptoms of tinea cruris?

A

Well marginated erthymatous half-moon plaque
Small vesicles may be seen, especially at the margin
Quite pruritic
Acute lesions are bright red
Chronic cases tend to have more of a hyper pigmented appearance, fine scaling may be present

33
Q

How do we differentiate jock itch from pubic lice?

A

They are both in the groin area
Jock itch will be scaly, itchy irregular shaped or round erythematous patches (consider history, i.e., recent athelete’s foot)
Lice is itchy, erythematous area, lice may appear as yellow/brown, skin may appear bluish and spotted

34
Q

How is tinea cruris managed?

A

Referal: same as tinea corpis
Topical antifungal is first line (imidazoles BID for 2-4 weeks). Apply to normal skin 2 cm beyond the affected area
Tolnaftate and undecylenic acid are also options
Allylamines or oral agents are for refractory cases
Prevention strategies: loose fitting clothes, boxer shorts, poweder to reduce moisture (not cornstarch), caution with regards to towels (use two different towels to reduce spread

35
Q

What is the prevalence of tinea pedis?

A

More common in males
Most common in adults (children under 12 should be referred)
Often associated with concomitant jock itch infection (groin inoculated with patient’s hand/towels)

36
Q

What are risk factors for tinea pedis?

A

Heat and dampness
Occlusive foot wear (winter boots, cleats and skates, steal-toed boots)
Use of public bathing facilities (pools, gyms, dorms)
High impact sports (marathon runners)
Sharing footwear, towels or other clothing with the infected individuals
Prolonged application of topical steroid
Hyperhidrosis (excessive sweating)

37
Q

What are the affected areas of tinea pedis?

A

Commonly affects toe webs, especially between the 4th and 5th toes
In some cases between the 3rd and 4th toes
May spread to soles of fee
Toenails may be involved (referral)

38
Q

Describe the presentation of tinea pedis

A

Interdigital maceration at web space
Fissuring and scaling
Pruritis and/or stinging sensation
Malodour (may be sign of infection)

39
Q

Whens should patients be referred?

A

Patient is a risk of delayed wound healing (i.e., has diabetes, cancer, peripheral vascular disease, immunocompromised, elderly, or malnourished
Children less than 12 years old
The lesion is weeping or severely inflamed, oozing, eczematous, painful
Toenail is affected

40
Q

What are the subtypes of tinea pedis?

A

Chronic interdigital type
Vesicular type
Moccasin (sandal)
Acute ulcerative type

41
Q

Describe chronic interdigital type tinea pedis

A

Most common type of infection (fissures, scaling, maceration)
Generally self treatable
Occurs between third/fourth and/or fourth/fifth toes
May be seasonal in nature

42
Q

Describe vesicular type tinea pedis

A 
Pruritic vesicles on the instep of the one or both feet
Some scales between tow webs
May be painful to some patients
Most prevalent during the summer months
Likely a referral
43
Q

Describe moccasin (sandal) tinea pedis

A

Off-white scaling (red) lesion of the soles and on the sides of feet
Generally found on both feet
Often involves nails (refer)

44
Q

Describe acute ulcerative type tinea pedis

A

Macerated, weepy lesions on soles of the foot

Often involved a secondary infection with gram negative bacteria (refer)

45
Q

What is tinea pedis and tinea manuum

A

Referred to as “two feet-one hand syn1drome”

46
Q

Describe tinea pedis management

A

Emphasize proper footcare/hygiene
Avoid occlusive footwear
Change to dry socks 2-3 times daily (cotton socks)
Dry between the toes BID and after showering
Change or alternate shoes
Topical antifungal is first line (imidazole) BID for up to 4 weeks. Apply to area and 1-2 cm surrouding.
Tolfnaftate and undecylenic acid is also an options
Refractory cases (or nail infections) may or will require prescription treatment

47
Q

What can pharmacists prescribe for tinea pedis?

A

Ciclopirox: apply to affected area twice daily for 4 weeks
Terbinafine: apply to affected area once daily for 1 week

48
Q

Why is it important to treat tinea pedis promptly?

A

To prevent individuals from developing tinea unguium or infections in the toe nails

49
Q

How is onchomycosis diagnosed?

A

Referral to physician is required. Diagnosis is confirmed through nail clippings, scapings under the nail and deep nail samples

50
Q

What are prescription treatment options for onchomycosis?

A

Oral terbinafine if first line.
Toenail requires 12-16 weeks of treatment
Fingernail requires 6 weeks
Risk of severe liver injury, therefore it requires close monitoring
Ciclopirox nail laquer has limited penetration into the nail. Slightly more effective than placebo. Requires daily application for 48 weeks

51
Q

What are all the tinea infections that require referral?

A 
Tinea capitis (scalp - involves scalp hair follicles; may extend to the eyebrows, eye lashes and beard. There are visible black dots. Occurs most often in children)
Tinea manuum (infrequent infection; "one hand two feet" presentation)
Tinea unguium (onchomycosis; nails become opaque, yellow, thick and progressively brittle and crumble)
Tinea nigra (must be differentiated from other hyper pigmentation conditions)
Tinea incognito (suppression of inflammatory response)
52
Q

Describe pityriasis versicolor

A

It’s an infection of the stratum corner by Malassezia
The upper trunk is a common area of occurrence (sebaceous glands)
Highest incidence in tropical envionrments, adolescents and young adults
Refer if causation is unclear

53
Q

What are the signs and symptoms of pityriasis versicolor?

A

Change in cutaneous pigmentation, lesions may be hypo pigmented or hyper pigmented
Lesions occur on back, chest and upper arms
Individual lesions are small but can coalesce to form larger patches
Fine scale presents
Cosmetic issue only
No itching associated

54
Q

How is pityriasis versicolor treated?

A

Selenium sulfide 2.5% shampoo - apply for 10 minutes, then wash off once daily for 7 to 14 days. Then use once or twice a month for prevention
Topical azole creams (apply BID for 2 weeks)
Ketoconazole 2% shampoo (one time application or once daily for 3 days. Leave on for 5 minutes then wash off
Recurrence is common (60-80%)

55
Q

What causes cutaneous candidiasis?

A

Candida albicans is the main organism

56
Q

What are risk factors for cutaneous candidiasis?

A 
Diabetes mellitus
Immunosuppression
Tropical environment
Poor hygiene
Psoriasis/contact dermatitis
Obesity
Individuals who have hands in water excessively
Overuse of "cornstarch" products/powders
57
Q

What are the affected areas for cutaneous candidiasis?

A 
Groin
Axillae (armpit)
Gluteal region
Under breasts
Skin folds (i.e., abdominal region)
Hands
58
Q

How does cutaneous candidiasis present?

A

Bright red
Moist skin surface
Scaling borders and satellite papule or pustules

59
Q

When should a patient with cutaneous candidiasis be referred?

A

Unsuccessful initial treatment (persistent infection) or condition worsens; causative factor unknown
Condition extensive, seriously inflamed or debilitating
Systemic or recurrent infection
Signs of secondary bacterial infection (presence of purulent discharge)
Immunocompromised patient
Patient less than 2 years old

60
Q

How is cutaneous candidiasis (intertrigo) managed?

A

Keeping the area dry (non-medicated powder; avoid cornstarch)
Topical antifungal OTC (imidazoles BID 2-3 weeks or nystatin cream/ointment BID-TID 2-3 weeks)
In mores severe cases, may use combination therapy: OTC topical anti fungal and topical corticosteroid, prescription treatment or oral therapy

61
Q

What are general management strategies of cutaneous fungal infection?

A

Non-presciption antifungal agents should be limited to superficial condition
Minimal area; no predisposing illnesses
Imidazoles are considered mainstay of superficial dermatophyte infections; but can also be effective for candida/mixed
Nystatin only useful in candida infections
Early clinical improvement (1-2 weeks) with relief of pruritus (monitoring parameter)
Full course of therapy should be followed to reduce the possibility of recurrence

62
Q

Can anti-fungal products be used in pregnancy and/or breastfeeding?

A

Clotrimazole is considered compatible with pregnancy and breastfeeding
Miconazole is considered compatible with pregnancy. There is no human data in regards to breastfeeding and it is considered probably compatible
Nystatin is considered compatible with pregnancy and breastfeeding

63
Q

Can anti-fungal products be used in children?

A

Clotrimazole, miconazole, tolnaftate and undecylenic acid can be used in children over 2 years

64
Q

What are some products that can be used in combination with anti-fungal agents?

A

Drysol (armpits), dehydral (feet) for hyperhydrosis
Fungal nail revitalizers/athlete’s foot wipes
Burosol (Burow’s solution = ammonium acetate) - use for 1 week to dry out wet athlete’s foot at least 10 minutes prior to using anti fungal agent (AF) - antiseptic, anti-inflammatory, drying agent
Hydrocortisone
Athlete’s foot wipes (tea tree oil/aloe vera) are not treatment options but may relieve symptoms

65
Q

Why would you use a cream?

A

It can be applied anywhere

66
Q

When would you use a powder?

A

For drying the area out (under the skin fold). But it’s difficult to keep in the area. It is also good for drying out a shoe, but the problem with that is if it’s cornstarch-based, the powder builds up and the moisture causes it to congeal and the fungus continues to grow

67
Q

Why would you use a spray?

A

May be good for areas that are difficult to apply

68
Q

What are non-drug measures to prevent the spreading of the infection to other parts of the body?

A

Use separate wash cloths and towels to wash/dry the affected area or wash that area last (pat dry thoroughly)
Do not share towels
Use hair dryer at low heat to dry intertriginous spaces (helps remove excess water) that towels cannot get to
Put socks on before underwear to avoid spreading tinea to the groin in the case of athlete’s foot
Launder contaminated towels and clothing in hot water to prevent spreading of the infection
Cleanse the skin daily with soap and water and thoroughly pat dry to remove oils that may support fungal growth
Avoid wearing clothing and shoes that allow the skin to stay wet. Wool and synthetic material fabrics prevent optimal air circulation
If possible, allow shoes to dry thoroughly before wearing them again
Wear protective footwear in public or in community showers/pools/saunas

69
Q

What should patients know?

A

How to apply the product and how often
Wash hands before and after application of antifungal agent/avoid getting into eyes
Do not apply any dressings to area (occlusion)
Use necessary hygienic measures to prevent the spread of the fungal infection
Other measures to prevent future infection
Key monitoring parameters
What to expect and when
Duration of treatment
OTC

70
Q

What are monitoring parameters?

A

Some relief of symptoms within 1-2 weeks
Monitor daily for infection (pus, redness, swelling) - see doctor if it occurs
Lesions should clear within treatment timeframe
If no improvement in 1-2 weeks or condition worsens, see physician

Clinical 1 (25 decks)

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