Superficial Fungal Skin Infection - Wright Flashcards Preview

Derm Rheum > Superficial Fungal Skin Infection - Wright > Flashcards

Flashcards in Superficial Fungal Skin Infection - Wright Deck (87):

what is the causative organism (in general) for tinea or "ringworm"

Dermatophyte - fungi that live in soil and on animals and humans.

They are capable of digesting keratin and invading hair, skin, and nails


what are the 3 main genera of dermatophyte that cause tinea infections





what is the most common dermatophyte infection in children

Tinea Capitis


what race is tinea capitis more common in

African American


What are the two most common causes of Tinea Capitis (what dermatophytes)

Trichophyton tonsurans

Microsporum canis


most M cani infections occur in what race of children



most T tonsurans infections occur in what race of children

African Americans


what is the most common transmission route for tinea capitis

human to human

asymptomatic carriage in humas appears to be a major reservoir for infection

also fomites


what are the clinical features of tinea capitis

scaling and patchy alopecia


in Tinea Capitis, is the scaling diffuse or localized? 

Scaling can be diffuse ("seb-derm" like) or localized 


"black dot" pattern of tinea capitis - due to broken hair shafts - which dermatophyte causes this most often?

T tonsurans it grows inside of hair shafts, weakens them, causes them to break off at scalp


if you see pustules (sign of inflammation) in the setting of Tinea Capitis, what should you have a high index of suspicion for?

primary fungal infection

need to obtain fungal culture


What is this? what is a potential consequence? 

Kerion this kind of inflammation may result in permanent scarring alopecia especially if it goes on long time without proper treatment


for tinea capitis, LAD is often seen where?

posterior cervical, sub-occipital

correlates well with + fungal culture in setting of scaling and alopecia


what is the gold standard for confirming the Dx of tinea capitis?

fungal culture

Know this $$


What is the utility of KOH use for viral culture - in suspected tinea capitis or some shit?

KOH application to the biopsied scale and/or broken hairs - helps to break down the skin cells, allows you to see fungal elements


how to you diff seborrheic dermatitis from tinea capitis?

seb derm is a more chronic problem

true seb derm is unusual after infancy and before puberty


how does seb derm present in infancy (to help diff from tinea capitis)

waxy yellow scale - known as cradle cap


How does seb derm present in teens - to help diff from tinea capitis



how do you diff psoriasis of the scalp from tinea capitis

erythematous plaques with silvery scale favors postauricular and posterior hairline


define alopecia areata. How do you diff it from tinea capitis

well-circumscribed smooth bald patches

generally, will not see any scales or skin changes - non-inflamed looking, no LAD


key point - what is the treatment of tinea capitis? (generally)

what specific drug is gold standard

what treatment type will not work

requires systemic antifungal to penetrate hair follicle

Griseofulvin is gold standard

topical antifungals will not work


what is unique about M canis regarding its treatment? compared to Tricophyton Toransusnusnus

M canis may require higher doses and longer course for clearance


what is the utility of an antifungal shampoo, like ketoconazole, in treatment of Tinea Capitis

may help to decrease risk of transmission

consider use by all household members shampoo

by itself will not treat the damn fungus


Terbinafine can also be used to treat tinea capitis; what are the common side effects and what should you do about them? know this $$

HA, GI upset, dizziness, drug reactions,

hepatotoxicity, rare hematologic

baseline ALT/AST is advised

CBC monitoring advised for immunodeficient pts


What is the downside of use of Terbinafine - what is it less useful for

less effective for M canis infection


if pt has a kerion, what treatment modality should you consider adding to your regimen

systemic steroids


define tinea corporis

superficial fungal infection of skin


what is the MCC of tinea corporis in young children?

M canis


what is the classic clinical manifestation of Tinea Corporis?

one or more well-defined annular scaly erythematous plaques with central clearing and a scaly, vesicular, papular, or pustular border


what is Majocchi's Granuloma?

granulomatous folliculitis - erythematous plaques or patches studded with papules and/or nodules deeper infection of follicles foregin body reaction


what is the treatment of Majochi's Granuloma?

cannot treat with topical antifungal

use systemic meds


how do you diff Nummular Atopic Dermatitis from Tinea Corporis?

NAD is not annular (everything round is not annular)

NAD is very very pruritic


how do you diff psoriasis from tinea corporis?

Psoriasis has "dull pink" erythema - silvery or white micacceous scale - nummular lesions - sheet like scales


how do you diff granuloma annulare from tinea corporis

granuloma annulare NO SCALES

raised, "rubbery" rim

location: dorsal hands, wrists, feet, ankles


what is the treatment for localized tinea corporis?

topical (i'm assuming antifungals)


start with topical tx for tinea corporis, if no improvement, what next?

reconsider dx or culture

culture +, proceed to oral therapy


what treatment does she prefer for tinea corporis

ketoconazole cream


This is impt

What is the final word on the use of combination products for treatment of tinea corporis? or anything?

do not use them

Antifungal + strong topical steroid

they often result in persistent/worsening infection (due to steroids immunosuppression)


define Tinea Manuum

who is it more common in?

skin of hands

most common in men (t. MANuum) 

rare in children


what are the clinical manifestations of Tinea Manuum? What are the two general patterns?

chronic dryness of palms with redness and scaling two patterns

palmar - fine scale, may be unilateral

dorsal - annular, red, scaly


what is on your DDx if you suspect tinea manuum

irritant or contact dermatitis, or psoriasis


what is the treatment for tinea manuum - specifically for each of the two types

dorsal - topical antifungal, it is typically limited

palmar - requires oral antifungal


Tinea Cruris

Jock itch

men more than women

rare in children


what are the risk factors for Tinea Cruris

Jock itch

obesity, heat, humidity


what are the clinical manifestations of Tinea Cruris? are your johnson and jingle bells typically involved?

Pruritic (very, very, very)

red, annular, scaly plaques over groin and medial thighs

Penis, Scrotum not affected (this is helpful for dx)


how do you diagnose Tinea Cruris?

KOH and fungal culture

This is standard of dx for all these fucking Tinea


what 4 other conditions are on your DDx if you suspect Tinea Cruris?

Candidiasis, Erythrasma, Psoriasis, Seb Derm


how do you diff Candidiasis from Tinea Cruris?

candidiasis has satellite pustules - this is impt


How do you diff erythrasma from Tinea Cruris

Erythrasma has NO SCALES

it also appears with coral red fluorsecence if you light it up with a Wood's lamp


Tx for Tinea Cruris? specific delivery form? what about if the jock itch is refractory?

topical AF, powders are helpful,

oral AF if refractory


Tinea pedis

"athlete's foot"

10% world's population


risk factors - occlusive shoes, communal showers (Group hug in the shower later!!)


what are the clinical manifestations of tinea pedis?

itching, scaling, blistering on soles, between toes


what is moccasin in the setting of tinea pedis

fine, dry scale over soles


what is vesiculobullous in the setting of tinea pedis

vesicular/bullae on soles, esp. insteps


What two conditions are on your DDx if you suspect Tinea Pedis?

Contact dermatitis, Dyshidrotic eczema


how do you diff contact dermatitis from tinea pedis

contact dermatitis - dorsal feet affected


how do you diff Dyshidrotic eczema from tinea pedis? what is the keyword presentation of D eczema?

"tapioca vesicles"

this will be more pruritic

culture will be key to DDx here


what is Tinea Unguium? what is another name for it?

nail infucktion Onychomycosis


epidemiology of Tinea Unguium (Onychomycosis)

60% over age 70, males


what are the general causes of Tinea Unguium (Onychomycosis)

non-dermatophyte molds, yeasts


what are risk factors for Tinea Unguium (Onychomycosis)

IS'd, diabetes, HIV, poor circulation, trauma, dystrophy


what are the clinical manifestations of Tinea Unguium?

discoloration, thickening, onycholysis


What are the 4 patterns of Tinea Unguium (Onychomycosis)

Distal subungual

Proximal subungual 

White superficial 



which of the 4 patterns of Tinea unguium is most common? and describe it

Distal subungual

invasion of distal nail plate, onycholysis with thickening and discoloration

spreads proximally back towards nail matrix


which of the 4 patterns of Tinea Unguium is pathognomonic with HIV (only seen in HIV)

proximal subungual

spreads distally


which of the 4 patterns of Tinea Unguium is this?

white superficial


which of the 4 patterns of Tinea Unguium is this?

Candida - classic presentation


What is Chronic Paronychia? what is most commonly seen with?

nail dystrophy

commonly seen with candida albicans


What is Trachyonichia? (DDx from tinea unguium)

20 nail dystrophy

may not affect all nails at first, but progress to it

"rough nails" - ridging, grooves, pitting, discoloration, fragility


what is trachonychia commonly associated with? (DDx from tinea unguium)



What are Beau's lines?

Transverse grooves of furrows

stress causes temporary arrest of nail matrix

nail may shed completely (Onychomadesis)

will grow back normally

I guess this is on your differential of tinea unguium


Suspect tinea unguium, what is a classic finding that will push you towards physical trauma as cause of nail dystrophy?

bilateral, symmetrical involvement of the longest toes, or the 5th toes whatever is jamming into shoes


Dx of Tinea Unguium - in addition to KOH prep and fungal culture of nail clipping, what else do you need to do?

PAS stain of nail clipping


are topicals effective in Tinea unguium?

no - they do not penetrate nail plate well and do not reach nail matrix


what is the common, effective treatment for tinea unguium

Terbinafine - again, need to do CBCs and LFTs (Sweatman - just CBCs)


tinea unguium treatment - how long must you treat for fingernails? toenails? why?

fingernails - 4-6 months

toenails - 12-18 months

time it takes for the nail to grow out, turn over


what is Tinea versicolor?

ptyriasis versicolor

common superficial fungal disorder of skin, commonly caused by yeast forms of dimorphic fungi - Malassezia furfur - part of normal skin flora


what is the clinical presentation of tinea versicolor

multiple scaling, oval macules, patches, and thin plaques over upper trunk, proximal arms, sometimes face and neck


what causes the hyper or hypopigmentation seen in Tinea Versicolor

Azelaic acid production


when is tinea versicolor more prominent?

during the summer - sun exposure intensifies pigmentation differences


How do you make the dx of T versicolor? what do you look for on KOH prep?

"spaghetti and meatballs" (hyphae and spores)


what are the two treatment options for T versicolor?

Selenium sulfide lotion/ shampoo or ketocoazole topical


T versicolor - severe, recurrent, fails topical therapy - what do you use? and what is a weird recommendation associated with this?

systemic ketoconazole work up a sweat - causes yeast to come out of skin and ketoconazole can affect it or something


you see Angular Chelitis with paronychia in the presentation, what fungal infection do you suspect


angular chelitis - oral commissures - painful, erythematous, small pustules


what is the tx for candidiasis?

topical anti-yeast cream and decrease moisture


What can happen if corticosteroids are used (improperly) for tx of Tinea Corporis? what is this called? 

may blunt the appearance 

Tinea Incognito