adult and pediatric cutaneous fungal infections Flashcards
estimated population affected by dermatophytoses
20-25%
superficial cutaneous fungal infectinos are limited to the _____ as opposed to systemic fungal infections
epidermis
three groups of cutaneous fungi that cuase superficial infections
dematophytes
- Malassezia* spp
- Candida* spp
dermatophytes
Trichophyton
Microsporum
Epidermophyton
areas that dermatophytes infect
keratinized tissues:
- stratum corneum
- the nail
- the hair
descrinbe this
erythema and scaling present on the plantar surface between the toes
Most common fungal infection seen in developed countries
tinea pedis
Tinea pedis caused by
Trichophytom rubrum
common sources of infection of tinea pedis
shoes provide ideal moist environment for fungal growth
public showers, gyms, swimming pools
clinical patterns of infection
interdigital
moccasin
vesiculobullous
most common location for tinea pedis
interdigital types
interdigitating tinea pedis
redness and scaling between the toes
tinea pedis: moccasin type
tinea pedis moccasin type
sharply marginated scale, distributed along lateral borders of feet, heels, and soles
vesicles and erythema may be present
tinea pedis moccasin type is often associated with
onychomycosis (nail fungal infection)
one hand, two feet syndrome
tinea pedis moccassin type shows unilateral fine scaling, particularly in the creases
and nails are often involved.
tinea pedis vesiculobullous type
grouped 2-3 mm vesicles or bullae are seen often on the arch or instep
can be itchy or painful
which tinea pedis is delayed hypersensitivity immune response to a dermatophyte?
vesiculobullous
what does KOH do to scales on glass slide
dissolves keratin
describe diagnostic featurs in this KOH exam
parallel walls throughout the entire length
septated and branching hyphae
how do we diagnose fungus of the hair, skin or nail?
KOH testing
topical antifungals for tinea pedis
imidazoles: fungistatic
allylamines: fungicidal
ciclopirox: fungicidal and fungistatic
imidazoles
fungistatic
ex. clotrimazole
miconazole
ketoconazole
allylamines
fungicidal (kills)
ex terbinafine
naftifine
ciclopirox
fungicidal and fungistatic
ex cicloprix olamine
complications of tinea pedis
lower leg cellulitis (creates portal of entry for bacteria)
tinea corporis - from autoinoculation
onychomycosis
chronic fungal infection of the nailbed, usually multiple nails
how can we determine between psoriatic onychomycosis or chronic fungal infection?
KOH test or pathology
effect of topics on onychomycosis
responds poorly
first line treatment for onychomycosis
oral terbinafine (250 mg daily) or azoles
required for at least 3 months!
tinea corporis
ringworm
dermatophytosis of the skin - usually affecting the trunk and limbs
tinea corporis ringworm
description of ringworm
sharply marginated, erythematous annuar lesion with central clearing and raised papulovesicular border with scaling
areas of the body tinea corporis affects
the trunk and limbs usually
tinea cruris
jock itch - ringworm presentation in the groin
signs and symptoms of tinea corporis
itching is most prominent symptom
asymmetric distribution
active border with central clearing
Tinea corporis description
annular lesion with central clearing
nomenclature
- body
- feet
- scalp
- hands
- face
- nails
- obscured by topical steroid
- tinea corporis
- tinea pedis
- tinea capitis
- tinea manuum (hands)
- tinea facei
- onychomycosis (tinea in nails)
- tinea incognito
treatment for tinea corporis
similar to tinea pedis: topical antifungals for 2 weeks minimum
if severe: oral terbinafine or fluconazole 1-2 w
tinea capitis
dermatophytosis of the scalp and associated hair
demographic of tinea capitis
common in african american children age 4-8
spread of tinea capitis
direct contact with animals, humans, fomites
most common tinea capitis in world
most common tinea capitis in US
- Microsporum canis (animal to human)*
- Trichophyyton tonsurans (human/fomite to human)*
tinea capitis with arthropsores inside the hair shafts
on KOH stain
differential diagnosis for tinea capitis
seborrheic dermatitis (erythema and greasy scale but no broken hair)
psoriasis (erythematous plaques with overlying silvery scale)
atopic dermatitis (eczematous skin lesions, severe itching and occasional bnrokemn hairs from scratching)
alopecia areata (well demarcated circular patches of complete hair loss)
seborrheic variant of noninflammatory tinea capitis
black dot variant of noninflammatory tinea capitis
what is a kerion
a painful, boggy, inflammatory mass with broken hair follicles
untreated capitis can progress to a kerion
can discharge pus
inflammatory tinea capitis kerion
treatment for tinea capitis
Griseofulvin in the US
Terbinafine is comparable
topical agents and tinea capitis
ineffective
diaper candidiasis description
beefy red confluent erosinos and marginal scaling in the area (inner thigh and abdomen) covered by a diaper in an infant, folds are affected
looks for satellite papules and pustules
pathogenesis of diaper candidiasis
wet and dirty diapers that are not changed regularly contribute to diaper dematitis due to urease enzymes in feces
disruptino of the epidermal barrier allows for entry of candida which is present in feces
treatment for diaper candidiasis
nystatin or imidazole creams or ointments are first line
hydrocortisone 1% cream or ointment in diaper candidiasis
may be used for significant inflammation but only for al imited time due to risk of skin atrophy and/or system absorption
don’t treat diaper candidiasis with
combination therapies - high potency topical steroids
oral nystatin
may be used if thrush is present or with frequent recurrance
diaper rash differential
atopic dermatitis
infantile psoriasis
irritant diaper dermatitis
tinea cruris
atopic dermatitis
red skin on an edematous surface with microvesiculation, very rare in diaper area
infantile psoriasis
sharply demarcated, erythematous papules and plaques involving the folds
irritant diaper dermatitis
erythma, erosion, spares skin folds, severe cases may show ulcerated papules and islands of re-epithelization
tinea cruris in the differential
well demarcated red/brown/tan plaques, inguinal fold are affected, rarely involves lavia, scrotum or penis
irritant dermatitis
diaper candidiasis
irritant diaper dermatitis treatment
improves with barrier creams - zinc oxide paste
more frequent diaper changes, looser fitting diapers
candidiasis could be a complicating factor
candidiasis of the large skin folds
candidal intertrigo
where does candidal intertrigo arise
groin or armpits
bewtween the buttocks
under large penduluous breasts
under overhanging abdominal folds
neck folds
KOH exam on candidal intertrigo
reveals pseudohyphae
symptom of candidal intertrigo
burns more than itches
predisposing factors to candidal intertrigo
diabetes mellitus
hot, humid weather
limited mobility
obesity
treatment of candidal intertrigo
topical antifungal agents
- polyenes (nystatin)
- imidazoles
allylamines are not used!
prevention of candidal intertrigo
hygiene, keep dry, weight loss
extensive or recalcitrant candidal intertrigo
systemic imidazoles
can combine with hydrocortisone cream to reduce symptoms rapidly, but limit to one week
candidal intertrigo
candidal intertrigo
psoriasis
well demarcated plaque with a thick silvery scale
common complication of tinea pedis
lower leg cellulitis in immunocompromised non diabetics
_____ is especially helpful in tinea corporis diagnosis when the source of infection is not obvious
culture
topical treatment used for
tinea pedis
tinea corporis
candidal intertrigo
oral medications are used for
extensive disease, tinea capitis, onychomycosis
always do a ________ when a child presents with a scaling rash concerning for fungal infection
diagnostic test - KOH prep or fungal culture
etiology of diaper dermatitis
irritant, inflammatory, infectious
seborrheic dermatitis in infants
usually resolves on its own with mild baby shampoos, topical ketoconazole shampoo or cream in persistent cases
commonly involved areas of seborrheic dermatitis in infants
cradle cap
behind ears
neck creases
axillae
diaper area
