mycology

• yeast

  round, form smooth flat colonies, reproduce by budding
• molds

  multicellular, composed of hyphae, growth appears fuzzy
• dimorphic


  switch from yeast to mold in response to environmental changes
• superficial mycoses

  grow on keratinised layers, fungi
• pityriasis versicolor

  healthy people, caused by Malassezia furfur, not contagious, caused by excessive sweating
• Pityriasis Versicolor appearance

  small pigmented macules that are irregular in shape and are sometimes covered by a fine layer of scales
• cutaneous myocoses

  dermatophyte infections (tineas), spread by direct contact, diagnosed by microscopic examination of skin scraping
• Species of three genera of fungi are usually the cause of infections:

  trichophyton, microsporum, epidermophyton
• tinea capitis

  childhood disease, person to person spread, caused by microsporum
• tinea barbae

  fungal outgrwoths, caused by trichophyton and micro abrasions during shaving
• tinea corporis

  red, scaly, itchy regions, spread from person to person, caused by trichophyton
• tinea manuum

  fine, scaly, pustular, itchy, caused by trichophyton
• tinea cruris 


  jock itch, caused by trichophyton or epidermophyton
• tinea unguium

  nail plate rises and seperates from the nail bed, caused by trichophyton
• Lymphocutaneous Sporotrichosis

  caused by dimorphic fungus, Sporothrix schenckii, infection of skin and lymph nodes, small nodule and then secondary nodules appearing along lymphatic channels
• Cryptococcosis (neoformans)

  yeast cells entering through respiratory system, can leave lungs and spread to other tissue
• Aspergillosis

  found in environment, infection is by inhalation of spores, pneumonia like infection, cutaneous infections as well
• Candida albicans

  dimorphic fungus, human to human contact, can become invasive