Fungal Infections in Human

• Fungal infections

  Also known as "mycoses"
• Mycoses

  Caused by certain yeasts, moulds, and dimorphic fungi
• How fungi can cause disease

  • Replication of the fungus (tissue invasion and functional disruption)
  • Immune response
  • Competitive metabolism (consumption of energy and nutrients intended for the host)
  • Toxic metabolites (ex: Candida spp produces acetaldehyde – a carcinogenic substance)
• Superficial mycoses

  Fungal infections of the outermost areas of the human body, including the outer surfaces of hair shafts and the outermost, nonliving layer of the skin

  
• Otomycosis

  A fungal infection in the outer ear, causing pain, itching, ringing in the ears, feeling of fullness in the ears, discharge of fluid from the ears, and hearing problems. Common fungi include Aspergillus species and rarely Candida.
• Otomycosis

  • Common in tropical and warm regions
  • Prevention: avoid getting water in ears, dry ears after showering, avoid cotton swabs, avoid scratching, use acetic acid ear drops
• Black piedra

  A fungal infection of the hair shafts, also known as "Trichomycosis nodosa". The fungal elements are attached to the hair shaft to form nodules along the hair shaft.
• Black piedra

  • Predominantly affects scalp hair, but also includes the beard, mustache, and pubic hair
  • Common in hot and humid countries
  • Caused by Piedraia hortae
  • Commonly seen in people having long hair and with the excessive use of different hair oils
  • Asymptomatic, hair shows firmly attached brown-black nodules (<1mm in size) that are gritty on palpation
• White piedra

  An asymptomatic superficial mycosis that affects the hair stems, forming whitish nodules caused by various species of the genus Trichosporon
• Tinea versicolor

  A common fungal infection of the skin that interferes with the normal pigmentation of the skin, resulting in small, discolored patches, usually on the trunk and shoulders. Caused by Malassezia furfur.
• Tinea versicolor

  • Patches may be lighter or darker in color than the surrounding skin
  • Mild itching
  • Scaling
  • Spaghetti and meatball appearance
• Tinea nigra

  An uncommon superficial dermatomycosis usually caused by Hortaea werneckii, presenting as persistent brown or black patches on the palms or soles.
• Tinea nigra

  • Unilateral or asymmetrical brown or black patches
  • Slightly scaly and do not itch or sting
  • Patches slowly enlarge
• Dermatomycoses

  Fungal infections of the living layers of skin (dermis), hair shafts, and nails

  
• Dermatophyte genera causing dermatomycoses

  • Trichophyton
  • Microsporum
  • Epidermophyton
• Tinea

  Dermatophyte infections of the skin, also called "ringworm", due to the ring-like appearance of the skin lesions they typically produce
• Tinea pedis

  Also known as "Athlete's foot", a fungal infection commonly caused by Trichophyton rubrum, a dermatophyte initially endemic only to a small region of Southeast Asia and in parts of Africa and Australia.
• Tinea pedis

  • Scaly, peeling or cracked skin between the toes
  • Itchiness, especially right after taking off shoes and socks
  • Inflamed skin that might appear reddish, purplish or grayish
  • Burning or stinging
  • Blisters
  • Dry, scaly skin on the bottom of the foot that extends up the side

  
• Prevention of tinea pedis

  • Let your feet air out
  • Wash your feet daily
  • Change socks regularly
  • Alternate pairs of shoes
  • Protect your feet in public places
  • Be aware of the risk factors for spreading the condition
• Tinea corporis

  Ringworm of the body, a rash caused by a fungal infection, usually an itchy, circular rash with clearer skin in the middle.
• Dermatophyte species causing tinea corporis

  • T. interdigitale
  • T. tonsurans
  • M. canis
  • T. verrucosum
  • T. equinum
  • T. erinacei
• Tinea corporis

  • Spread by the shedding of fungal spores from infected skin
  • Transmission facilitated by warm, moist environment and sharing of fomites
  • Incubation period of 1-3 weeks
  • Dermatophyte invades and spreads in the stratum corneum, but unable to penetrate deeper layers in healthy skin
• Signs and symptoms of tinea corporis

  • A scaly ring-shaped area, typically on the buttocks, trunk, arms and legs
  • Itchiness
  • A clear or scaly area inside the ring, perhaps with a scattering of bumps
  • Slightly raised, expanding rings
  • A round, flat patch of itchy skin
  • Overlapping rings
• Clinical variants of tinea corporis

  • Kerion
  • Tinea gladiatorum
  • Tinea imbricata
  • Tinea incognita
  • Majocchi granuloma
  • Bullous tinea corporis
• Tinea capitis

  A disease caused by superficial fungal infection of the skin of the scalp, eyebrows, and eyelashes, with a propensity for attacking hair shafts and follicles.
• Tinea capitis

  • Usually causes itchy, scaly, bald patches on the head
  • Can be spread through direct skin-to-skin contact, contact with infected animals, or contact with contaminated objects
• Steps to reduce risk of tinea capitis

  • Educate yourself and others
  • Shampoo regularly
  • Keep skin clean and dry
  • Avoid infected animals
  • Avoid sharing personal items
• Tinea cruris

  Also known as "jock itch", a fungal infection that causes a red and itchy rash in warm and moist areas of the body, often affecting the groin and inner thighs.
• Fungi causing tinea cruris

  • Trichophyton rubrum
  • Epidermophyton floccosum
• Tinea cruris

  • Rash often begins with a reddened area of skin in the crease in the groin, often spreading to the upper thigh in a half-moon shape
  • Rash may be ring-shaped and bordered with a line of small blisters
  • May burn or feel itchy, with flaky or scaly skin
• Risk factors for tinea cruris

  • Being male
  • Being a teen or young adult
  • Wearing tight underwear
  • Being overweight
  • Sweating heavily
  • Having a weakened immune system
  • Having diabetes
• Steps to reduce risk of tinea cruris

  • Stay dry
  • Wear clean clothes
  • Find the correct fit
  • Don't share personal items
  • Treat or prevent athlete's foot
• Tinea unguium

  Also known as onychomycosis, a fungal infection of the toenails or fingernails that may involve any component of the nail unit.

  
• Patterns of tinea unguium

  • Lateral onychomycosis
  • Subungual hyperkeratosis
  • Distal onycholysis
  • Superficial white onychomycosis
  • Proximal onychomycosis
  • Complete destruction of the nail
• Subcutaneous mycoses

  Fungal infections of the dermis and underlying tissues, more severe than superficial and cutaneous mycoses, resulting from traumatic implantation of the mould through the dermis into the subcutaneous tissue.
• Sporotrichosis

  A subcutaneous mycosis
• Tinea unguium

  Fungal infection of the toenails or fingernails that may involve any component of the nail unit, including the matrix, bed, or plate

  
• Trichophyton rubrum and T. interdigitale

  Most common causes of tinea unguium
• Patterns of tinea unguium

  • Lateral onychomycosis
  • Subungual hyperkeratosis
  • Distal onycholysis
  • Superficial white onychomycosis
  • Proximal onychomycosis
  • Complete destruction of the nail
• Subcutaneous mycoses

  Fungal infections of the dermis and underlying tissues, more severe than superficial and cutaneous mycoses