LECTURE 1 dr. Sisi

• Main learning objectives

  • To list and identify the common dermatophytes causes fungal cutaneous and subcutaneous infection
  • To describe the pathology and clinical presentation of fungal infection of the skin, nail, hair, and subcutaneous
  • To choose the simple method of fungal laboratory investigation for clinical specimen
  • To name the drug of choice for the treatment of each infection
  • To aware with the transmission and epidemiology of these infections
• Mycoses: diseases cause by fungi
• Types of mycoses

  • Cutaneous
  • Subcutaneous
  • Systemic: Endemic, Opportunistic

  
• Cutaneous mycoses

  • Affect the dead layer of skin, epidermis, hair, nails
  • Representative diseases: Tinea-versicolor, Dermatophytosis
  • Causative organisms: Malassezia, Microsporum, Trichophyton, Epidermophyton

  
• Subcutaneous mycoses

  • Affect the subcutis
  • Representative diseases: Mycetoma, Sporotrichosis
  • Causative organisms: Several genera, Sporothrix
• Opportunistic mycoses

  • Affect internal organs
  • Representative diseases: Candidiasis, Aspergillosis, Cryptococcosis, Mucormycosis
  • Causative organisms: Candida, Aspergillus, Cryptococcus, Mucor, Rhizopus
• Systemic mycoses

  • Affect internal organs
  • Representative diseases: Histoplasmosis, Blastomycosis, Coccidioidomycosis, Paracoccidioidomycosis
  • Causative organisms: Histoplasma, Blastomyces, Coccidioides, Paracoccidioides
• Fungal infection has emerged as a worldwide health-care problem in the last decade
• Why care about fungal infections?

  • Fungi are a leading cause of nosocomial infections
  • Fungal infections are a major problem in immune suppressed people
  • Fungal infections are often mistaken for bacterial infections, with fatal consequences
• Superficial mycosis is still ranked as one of top infectious skin diseases in Indonesia

  
• In the last 3-5 years, among the various superficial mycosis, dermatophytoses was the most frequent type reported, followed by pityriasis versicolor and candidosis

  
• A recent epidemiologic survey in a rural area in Java showed that pityriasis versicolor was the most frequent finding, and tinea was more frequently found located on the body

  
• Cutaneous mycoses: Dermatophytoses (Ringworm/Tinea)

  • Caused by Dermatophytes (Trichophyton, Microsporum, Epidermophyton)
  • Transmitted by direct contact with skin scales

  
• Dermatophytoses only infect superficial keratinized structures (skin, hair, nails), not deeper tissues

  
• Types of dermatophytoses

  • Tinea capitis
  • Tinea corporis
  • Tinea cruris
  • Tinea pedis
  • Tinea unguium
  • Tinea favosa
  • Tinea barbae
  • Tinea imbricata

  
• Tinea cruris was the major type of dermatophytoses, exceeding tinea corporis
• Tinea capitis showed a decline in frequency, but tinea unguium and onychomycosis were more frequent
• Tinea imbrikata was only reported from Manado and Papua
• There was an increasing report of unusual and widespread clinical findings of dermatophytoses in immunocompromised individuals
• Dermatophytoses

  • Chronic infection in warm, humid areas of the body
  • Typical ringworm lesions with inflamed circular border, papules, vesicles, and clear central area
  • Broken hairs
  • Thickened broken nails

  
• Dermatophytes are molds that use keratin as a nutritional source, not dimorphic, and their habitat is mainly human skin (except Microsporum canis which infects dogs and cats)
• Ringworm infection

  • On cat
  • On human skin

  
• Tinea capitis

  • Dermatophytosis of the scalp hair follicle, caused by Microsporum and Trichophyton
  • Clinical findings: black dot, gray patch, scaling patches of alopecia with broken hairs
• Tinea corporis

  • Dermatophytosis of the glabrous skin of the face, trunks, and limbs
  • Synonyms: ringworm, circinattina

  
• Tinea cruris

  • Dermatophytosis of the medial upper thighs and the inguinal, pubic, perineal, perianal areas
  • Synonyms: eczema marginatum, ringworm of the groin, tinea inguinalis, gym itch
  • Major causative agent: Trichophyton rubrum, others: Trichophyton mentagrophytes, Epidermophyton floccosum

  
• Tinea imbrikata

  • Caused by Trichophyton concentricum, only reported from Manado and Papua
• Tinea pedis (Athlete's foot)

  • Dermatophytosis of the feet
• Tinea unguium

  • Dermatophytosis of the fingernails or toenails

  
• Dermatophytoses laboratory diagnosis

  1. Microscopic examination of KOH 10% preparation of skin scales to detect hyphae

  2. Culture on Sabouraud's agar to identify by mycelium and asexual spores

  
• KOH preparation of skin scales from a dermatophytosis patient

  • Epidermal cells lysed
  • Visible long, septate, branching hyphae
  • Hyphae sometimes fragmented into arthrospores

  
• In 1980, Trichophyton rubrum was the major causative agent of dermatophytosis, followed by Epidermophyton floccosum, Trichophyton mentagrophytes, and Microsporum canis
• In 2008, Trichophyton rubrum remained the major causative agent, followed by Trichophyton mentagrophytes, Microsporum canis, and Microsporum gypseum
• Dermatophytoses treatment

  • Topical agents like miconazole, clotrimazole, tolnaftate, undecylenic acid
  • Griseofulvin
• Dermatophytoses prevention

  Keep skin dry and cool
• Pityriasis versicolor (Tinea versicolor)

  • Chronic, mild, usually asymptomatic infection of the stratum corneum
  • Caused by Pityrosporum (Malassezia) furfur
  • Transmitted by direct contact with skin scales

  
• Clinical types of Pityriasis versicolor

  • Lesions vary in color (hypo/hyperpigmented) based on patient pigmentation, sun exposure, and severity
  • Lesions on face, neck, shoulders, arms, with slight scaling or itching, usually asymptomatic

  
• Pityriasis versicolor laboratory diagnosis

  Direct KOH examination of skin scales shows pathognomonic round, budding yeast cells and short, septate, occasionally branched hyphae fragments

  
• Culture is not usually done for Pityriasis versicolor
• Pityriasis versicolor treatment

  Topical azoles (e.g. miconazole, ketoconazole)
• Subcutaneous mycoses: Mycetoma

  • Chronic, locally progressive, destructive, suppurative, and granulomatous disease
  • Begins in the subcutaneous tissue, usually of the foot, involving subcutaneous tissue, fascia, and bone
  • Characterized by draining sinuses and presence of granules