Skin and soft tissues infections

Classification of mycoses

Superficial and cutaneous

Subcutaneous

Deep (systemic)

Superficial mycoses

Caused by fungi living as

saprophytes

Hair, dead skin and lipids secretions

They don’t provoke any immune

response

No pain or itching

Pityriasis versicolor

Common, mild and chronic infection

of stratum corneum

World-wide

More common in tropics and sub-

tropics

In temperate regions more common

during summer

Pityriasis versicolor Caused by Malassezia

yeast, which is lipophilic dimorphic

fungus

KOH Parker ink staining

Tinea nigraTypical brown to black, non-scaling macules on

the palmar aspect of the hands. 

Note: there is no inflammatory reaction

Cutaneous mycoses

Infections in the living parts of the body:

Skin

Hair and nail

Mucocutaneous membranes

Genitalia

Tow types can be recognized

Dematophytes infections

Non-dermatophytes infections

Dematophytes infections(dematophytosis)

Ringworm (hair and skin)

Favus (hair)

Onychomycosis (nail)

Dermatophytosis(=Tinea = Ringworm)

Infections of the skin, hair and nails

due to a group of related

filamentous keratinophilic fungi

called dermatophytes

Dermatophytes

Microsporum Hair, skin

Epidermophyton Skin, nail

Trichophyton Hair, skin, nail

Digest keratin by their keratinases

Resistant to cycloheximide

Epidemiology and natural habitat

Some have a world-wide distribution

Some are restricted to particular

regions

About 10 species are common

causes of human infection

Classified into three groups

depending on their usual habitat

Anthropophilic

Human is usual host

T. rubrum (foot & nail infections)

E. floccosum (foot & nail infections)

T. tonsurans (scalp infections)

M. audouinii (scalp infections)

Geophilic

Normal habitat is soil

Can cause infections in both humans

and animals

Microsporum gypseum

Zoophilic

Often associated with a particular

animal

Microsporum canis: cats and dogs

Trichophyton verrucosum: horse and

cattle

Dermatophytosis

Skin: Circular dry lesions

Slightly raised red scaly margins

Surrounded by red itchy skin

Fungus remain restricted to stratum corneum

Metabolites provoke inflammation

Hair: Typical lesions → scarring + alopecia

Nail: Thickened, deformed, fragile, discolored

Sub-ungual debris accumulation

Dermatophytosis clinical classification

Infection is named according to the

anatomic location involved

Clinical manifestation (1)

Ringworm

Tinea pedis (athlete's foot)

Tinea manuum (hands)

Tinea corporis (trunk, neck and back)

Tinea cruris (hairy skin around the genitilia)

Tinea barbae (hairy skin in the face)

Tinea capitis (scalp and eyebrows)

Clinical manifestation (2)

Favus (scalp)

Onychomycosis (nail)

Athlete's foot

(Tinea pedis )

Tinea pedis

Tinea manuum

Tinea manuum

Tinea manuum

Tinea corporis caused by M. canisfollowing contact with infectious cat

Tinea corporis

Tinea of the groin showing typical

erythematous lesions on the inner thighs

Tinea of the buttocks

Tinea cruris

Tinea barbae

Tinea capitis caused by M. canisfollowing contact with infectious cat

Tinea capitis showing extensive hair losscaused by M. canis

Favus and Onychomycosis

Favus Special form of tinea capitis

Onychomycosis Fungal infection of nail

The term "tinea unguium" is used specifically

to describe dermatophytic onychomycosis

Favus

Tinea capitis showing alopecia

Tinea of the nails caused by T. rubrum

Laboratory diagnosis

50 % of suspicious materials may be negative

Hyphae and/or arthrospores is diagnostic

Culture is more reliable:

Determined species

Source of infection

Can be positive even if direct examination is

negative

Hyphal elements seen in skin scraping preparation

Management

Dependant on the clinical setting

Topical or oral antifungal

Infection Recommended Alternative

Tinea unguium[Onychomycosis]

Terbinafine 250 mg/day6 weeks for finger nails,12 weeks for toe nails.

Itraconazole 200 mg/day/3-5 months or 400 mg/day for one week per month for 3-4 consecutive months. Fluconazole 150-300 mg/ wk until cure [6-12 months].Griseofulvin 500-1000 mg/day until cure [12-18 months].

Tinea capitis

Griseofulvin 500mg/day[not less than 10 mg/kg/day]until cure [6-8 weeks].

Terbinafine 250 mg/day/4 wks.Itraconazole 100 mg/day/4wks. Fluconazole 100 mg/day/4 wks

Tinea corporis

Griseofulvin 500 mg/day untilcure [4-6 weeks], often combined with a topicalimidazole agent.

Terbinafine 250 mg/day for 2-4 weeks.Itraconazole 100 mg/day for 15 days or 200 mg/day for 1week.Fluconazole 150-300 mg/week for 4 weeks.

Tinea crurisGriseofulvin 500 mg/dayuntil cure [4-6 weeks].

Terbinafine 250 mg/day for 2-4 weeks.Itraconazole 100 mg/day for 15 days or 200 mg/day for 1week.Fluconazole 150-300 mg/week for 4 weeks.

Tinea pedisGriseofulvin 500mg/dayuntil cure [4-6 weeks].

Terbinafine 250 mg/day for 2-4 weeks.Itraconazole 100 mg/day for 15 days or 200 mg/day for 1week.Fluconazole 150-300 mg/week for 4 weeks.

Chronic and/orwidespread

non-responsivetinea.

Terbinafine 250 mg/dayfor 4-6 weeks.

Itraconazole 200 mg/day for 4-6 weeks.Griseofulvin 500-1000 mg/day until cure [3-6 months].

Oral management options

Non-dermatophytes cutaneous infections

Onychmycosis

Intertrigo

Mucocutaneous candidiasis

Thrush

Vulvo-vaginitis

Intertrigocaused by Candida albicans

Red macerated rash under pendulous breasts is a common presentation of cutaneous candidiasis

Candida diaper dermatitis

This condition should

not be considered a

primary Candida

infection as it preceded

by an irritant dermatitis

Subcutaneous Mycoses

Skin, subcutaneous tissues, fascia

and bone

Localized

Trauma

More in tropics

Mycetoma, chromomycosis and

sporotrichosis

Mycetoma

Mycetoma

SporotrichosisA 60-year-old woman developed multiple subcutaneous

nodules and abscesses on her right hand and forearm 7 days after finger thorn prick

Sporotrichosis

ClassicalChromoblastomycosis:Fonsecaea pedrosoi

De Hoog, Centraalbureau voor Schimmelcultures

Nodulose chromoblastomycosis(Senegal): Fonsecaea pedrosoi

De Hoog, Centraalbureau voor Schimmelcultures

Management

Difficult

Surgical excision

Itraconazole and other antifungal