1. FUNGAL SKIN INFECTIONS

2. Fungal skin Infections
The most common cutaneous infection
Referred to as ring worm infections
Usually superficial and can involve hair, nail, skin.
Tinea capitis,tinea corporis, tinea pedis
Three genera of fungi: Trichophyton, Microsporum and Epidermophyton
Predisposing factors:
Trauma to the skin: blisters
Diabetes or immunocompromised patients
Skin occlusion, high humid conditions
Tinea pedis: Athlete’s foot: the most prevalent fungal infection
More common in adults than in children, more in men than in women,
Tinea corporis: common among children, hot and humid conditions, individuals under stress and overweight
Tinea capitis: scalp is involved, common among children

3. Environmental factors play an important role
Epidemiology
Trauma
Environmental factors play an important role
Chronic health problems and medications that weaken immune response
Tinea pedis is the most common infection
Etiology: three genera of pathogenic fungi: trichophyton, microsporum and epidermophyton
Transmission: contact with infected people, fomites. Environmental factors
Pathophysiology:
Inoculation
Incubation period: dermatophyte grows in SC, minimal signs of infection
Infection is established: fungal growth rate vs epidermal growth rate
Serum inhibitory factor inhibits further growth
Dermatophyte starts secreting enzymes and keratinases and reach the viable epidermis
Cell mediated immunity starts: inflammation and pruritis
Signs and symptoms of infection
Mild itching and scaling to severe exudative inflammatory process. Fissuring, crusting and discoloration of the skin

5. Tinea Pedis
Four accepted variants are present
Chronic intertriginous type: most common, fissuring , scaling, maceration in the interdigital space. Malodor, pruritis.
Chronic papulosquamous: both feet, mild inflammation and diffuse scaling of the soles
Vesicular type: small vesicles. Skin scaling may be seen
Acute ulcerative type: macerated weeping ulceration on the sole. Hyperkeratosis and pungent odor
Infection may trigger a bacterial overgrowth
BE CAREFUL WHEN:
Toe nail is involved, vesicular
eruptions with ooszing,
eczematous eruptions with
blisters, diabetic patients

6. Tinea unguium: nails are infected
The gradually loose their shiny luster and become opaque
If untreated, the nails become thick, yellowish and friable
The nail may separate from the nail bed and may be lost

7. Tinea corporis: has diverse clinical presentation.
Lesions start as small circular erythematous scaly areas
Spread peripherally and the borders may contain vesicles.
Pruritis

9. Tinea capitis: most prevalent between 3 - 7 years of age.
It is slightly more common in boys than girls.
More common in crowded living conditions.
The fungus can contaminate hairbrushes, clothing, towels and the backs of seats. The spores are long lived and can infect another individual months later.
Tinea capitis may present in several ways.
1. Dry scaling – non inflammatory. Small papules surrounding the shafts, like dandruff but usually non inflammatory, spreads centrifugally, hair lesions are dull gray in color, hair breaks off the scalp
2. Inflammatory, pustules to kerions/ Kerion: weeping lesions, exudates, form thick crusts on the scalp. Pruritis, fever, pain, lymph nodes
3. Black dots - the hairs are broken off at the scalp surface, which is scaly
Smooth areas of hair loss
4.Favus – patchy areas of hair loss, yellow crusts and matted hair
Untreated kerion and favus may result in permanent scarring (bald areas).

11. Treatment of fungal skin infections
Goals: provide symptomatic relief, eradicate the infection, prevent future infections
Pharmacologic agents: antifungals, antiinflammatory agents, astringent salts for tinea pedis before therapy
Patient compliance: 2-4 weeks for the infection to be eradicated
Non pharmacologic measures: keep the skin dry and clean, avoid sharing personal articles
Antifungals:
Clioquinol 3%: pedis, corporis
with hydrocortisone
Clotrimazole, miconazole nitrate: pedis and corporis
Terbinafine hydrochloride: 1%
Tolnaftate
Salts of aluminum: no direct antifungal effect, reduce iflammation, astringents, decrease edema, inflammation and irritation. Aluminum acetate and chloride