بسم الله الرحمن الرحيم
FUNGAL INFECTIONS
Fungal infections of skin Superficial Deep Skin Start in internal organs e.g. Madura foot
Superficial infections Dermatophytes Yeasts Microsporum Candida Trichophyton Malassezia Epidermaphyton furfur
DERMATOPHYTES
Tinea Capitis (Scalp): 4 distinctive types: Scaly ringworm. Black dot. Kerion. Favus.
1) Scaly Type: School children. Single or multiple. Oval bald patches with fine gray-white scales. Hairs Loose and break off. Cause T. violaceum & M. canis.
2) Kerion: Boggy swelling like abscess with loss of hairs. Scarring and permanent baldness. Animal origin. Cause T. verrucosum, M. canis. NB: Never to be incised.
3) Favus: Children and adults. Skin and nails. Yellow cup-shaped sulphur crusts of mousy odor known as scutula around loose hairs. Permanent scarring. Cause T. schoenleinii.
4) Black Dot Type: No stumps of hair. Break off near the surface. Cause T. violaceum.
Diagnosis: Clinically. Wood’s light. 20% KOH (Microscopic exam.). Culture on Sobaoraud’s agar.
Tinea Circinata: Tinea Barbae (Beard): Annular lesion with healing centre. Active edge Red, elevated and scaly. Itching. Tinea Barbae (Beard): Superficial type Similar to T. circinata. Deep type Marked inflammation and pustular folliculitis (Kerion-like).
Tinea Pedis: Ringworm of the foot. Tropical areas, summer. Bilateral and recurrent. Three clinical types: Interdigital: skin is sodden, red and macerated. Vesicular: sides and back of the feet. Hyperkeratotic: Thickened and scaly lesions.
Tinea Cruris: Ringworm of the groin. Heat, friction and obesity are predisposing factors. C/P: Small erythematous patches. Bilateral. Spread peripherally and clear in centre. Well-defined active lower edge.
Onychomycosis: Ringworm of nails. C/P: Discoloration, ridging, cracking, subungual hyperkeratosis or onycholysis. NB: Prolonged therapy (6-8 weeks) is needed.
CANDIDIASIS
Cause: Candida albicans. 2 forms: Yeast form (Commensal). Mycelia form (Pathogenic). **The latter is pathogenic under: Corticosteroids / Chemotherapy / Antibiotics / Drugs / Lymphoma / AIDS……
C/P: 1) Oral candidiasis: 2) Cutaneous form: Pseudo-membrane (Oral thrush). Angular chellitis. 2) Cutaneous form: Intertrigo: Groins, axillae, … Papulovesicles, well defined red moist patches. Erosive interdigitalis: Maceration, sodden skin. Paronychia: Nail fold is affected; red, tender swollen with discoloration, ridging and thickening of nail plate may occur.
4) Systemic candidiasis: 3) Napkin dermatitis: Diaper area of new-born. Confluent erythema with a sharp border with satellites papules. Depth of flexures are affected (D.D. contact dermatitis). 4) Systemic candidiasis: Via blood stream Many organs; it’s associated with fever.
Treatment: 1) Correction of underlying factors: DM. 2) Mucocutaneous: Systemic: Fluconazole. Topical: Dyes / Nystatin cream. 3) Systemic: Amphotericin B / Ketoconazole / Fluconazole.
Tinea versicolor: Very common / Familial predisposition. Cause: Malassezia furfur. C/P: Sharp demarcated macule with branny scales. Hyper or hypopigmented. Wood’s light: Yellow color Treatment: Systemic Ketoconazole / Fluconazole. Topical Imidazoles / Selenium sulphide.
Antifungal agents: 1) Topical antifungal: 2) Systemic antifungals: Whitfield ointment. Castallani’s paint. Imidazoles: Clotrimazole / Miconazole. 2) Systemic antifungals: a) Griseofulvin: Against all dermatophytes No value in yeast infections. 12.5 mg/kg/day after meals. Side effects: Hepatitis / Headache / Nausea / Drug interactions.
b) Ketoconazole (Nizoral): Against dermatophytes and yeasts. 200-400 mg/ day with food. Side effects: Hepatitis / Interaction with drugs. c) Triazoles (Itraconazole; Sporonox): Given for 1 week / month for 2-3 months. Have less side effects. d) Allylamines (Terbinafine; Lamisil): Against dermatophytes only.
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