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Chapter 33. Topical Fungal Infections Revised 8/15/10. Fungal Prevalence. 20% of U.S. residents may be affected Tinea pedis most common Tinea corporis, cruris next most common Tinea capitis incidence falling. Fungal Epidemiology: General. High temperature High humidity
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Fungal Prevalence 20% of U.S. residents may be affected Tinea pedis most common Tinea corporis, cruris next most common Tinea capitis incidence falling
Fungal Epidemiology: General High temperature High humidity More common: tropical and subtropical areas Immunocompromised patients Those with mild skin trauma or maceration from occlusion
Tinea Pedis Epidemiology Athlete’s foot; ringworm of foot White urban dwellers Adults ages 15-40; more common in males Those using communal bathing facilities, swimming pools, summer camps, sports clubs, gyms Marathon running: foot trauma
Tinea Corporis Epidemiology Ringworm of the body From persons or animals (cat/dog) Transfer from tinea capitis Most common prepubertal tinea (day-care center spread common) Warm climates, overweight, stress Tinea corporis gladiatorum: wrestling transmission
Tinea Cruris Epidemiology Jock itch Summer Intertriginous skin: maceration facilitates warm, moist environment More in males, scrotal skin folds Rare in prepubertal children Postpubertal males 18-40 highest risk group
Tinea Capitis Epidemiology Ringworm of scalp More in pediatrics; poorer hygiene Playing with infected brushes, combs, toys, telephones Contacting infected cat or dog Black children: occlusive hair dressings/ tight braids
Tinea Unguium Epidemiology Onychomycosis 30% of those over the age of 60 Toenails of those who also have tinea pedis
Tinea Versicolor Epidemiology Warm, humid weather Underlying immune deficiency Oily/greasy skin Hyperhidrosis: excessive foot sweating
Tinea Nigra Epidemiology Temperate climates Younger patients Females Palms and soles
Causes of Superficial Tineas Trichophyton, Microsporum, Epidermophyton Anthropophilic fungi: person-to-person (most common) Zoophilic fungi: animal-to-person Geophilic fungi: soil-to-person
Manifestations of Fungal Skin Infections • Anthropophilic: little inflammation • From pets or soil: Acutely inflamed; allergies to fungal antigens
Manifestations: Tinea Pedis 3 forms Intertriginous: macerated, boggy, white, thick, odorous, pruritic between toes Acute vesicular: inflammation, fissuring; 2˚ bacterial infections; odorous, pruritic; extreme pain in walking Moccasin: chronic, nonvesicular, over plantar foot
Manifestation: Tinea Pedis Flares in the summer; abates in winter May cause tinea manuum: “one-hand, two-foot disease”; Hands are dry, red, scaly
Manifestations: Tinea Corporis Glabrous skin (smooth and bare) Not on scalp, feet, hands, groin, ears, face Oval, scaly patch with inflamed border Centrally, skin often appears lighter or normal; thus, the lesion appears to be a ring circling beneath the skin surface 15-20 lesions over the body Lesions coalesce: polycyclic appearance
Manifestations: Tinea Cruris Sharply defined lesions Inflamed borders, reddish-brown centers Begins in groin skinfolds Spreads to perineum, thighs, buttocks Intense pruritus Sweating causes overt pain 2˚ bacterial infection possible
Manifestations: Tinea Capitis Circular patch of scaly skin Dry, noninflammatory dermatosis Patchy areas of hair loss Crown, parietal areas “Black dots”: hairs broken off at the scalp Kerion or favus: both worse involvement
Manifestations: Other Tineas Unguium: opaque, yellow nails; thickened; brittle, crumbled; nail lifts and may be lost Versicolor: lesions darken in winter, lighten in summer Nigra: black, brown discoloration on palms, lesions may coalesce; no scaling, nonpruritic, painless
Tinea Incognito Inappropriate assumption that lesions are allergenic in etiology Treatment of the lesion with steroids Steroid decreases inflammatory barriers, allowing spread to accelerate As spread accelerates, patient increases use of steroids
Tinea Treatment Guidelines Be sure lesions are fungal Check for other medications or medical conditions causing lesions Ointments last longer than creams Aerosols easy to use on skin and in shoes Only self treat: pedis, cruris, corporis Continue for full course of therapy
Tinea Pedis Treatment If topicals ineffective, orals may be necessary 2˚ bacterial infections may require antibiotics May also need antiperspirants Recurs in 70% of patients
Tinea Corporis Treatment • If condition does not clear, may be • Psoriasis • Eczema • Medication-induced eruptions • More severe fungal pathogens
Tinea Cruris Treatment Responds more readily to therapy than tinea pedis or tinea corporis Treatment times are shorter
Tineas Requiring Referral Tinea capitis: Topical medications do not penetrate follicles Tinea Unguium: Forget Fungi-Nail; requires systemic therapy Tinea Versicolor: Requires Rx meds Tinea Nigra: Differentiate from other pigmentation such as melanoma: requires Rx meds
Self-Care Only pedis, corporis, cruris Not for nails, scalp, vaginal yeast infections, diaper rash Supervise children External use only Keep from eyes Clean skin with mild soap first Apply morning and night
Therapeutic Choices: Classify By Cure Rates/Dosing • First Generation: Longest cure rates • Second Generation: Shorter cure rates • Third Generation: Shortest cure rates for tinea pedis coupled with once-daily dosing
First Generation (Oldest) • First Generation: use down to 2 years • Undecylenic acid: around pre-1970s • Tolnaftate: OTC in 1971 • Miconazole: OTC in 1982 • Clotrimazole: OTC in 1989 • Use 4 weeks for corporis & pedis, 2 weeks for cruris • Age limit is 2 years
Clotrimazole Occasional burning, stinging, peeling, other minor local reactions
Clotrimazole Products: Lotrimin AF for Her and Fungi Cure Intensive
Miconazole Nitrate Occasional burning and irritation Otherwise, safe and effective ingredient
Miconazole Products: Neosporin AF, Desenex Powder, Cruex Spray
Lotrimin AF Differences Note that some dosage forms of Lotrimin AF are clotrimazole, where others are miconazole Evidently, clotrimazole cannot be produced in any aerosol form
Tolnaftate Irritation on excoriated skin Only ingredient proven to prevent recurrences: apply to dry feet 1-2 times daily, at start of spring/summer
Tolnaftate Products: Tinactins Tinea pedis spray Jock Itch spray