Fungal Skin Infections

1.  Tinea Versicolor

• Distribution is across chest, back and shoulders
• Apparently everyone has this on there skin but it only causes lesions in some people
• Characteristics
  • Sharply demarcated macules with a central confluence
  • There is a scale but its only visible on scraping
• Do a KOH stain to diagnose:  see short and stubby hyphea and small spores (spaghetti and meatballs if you will)

2.  Dermatophytosis (better known as ring worm)

• Well defined patches of erythema and scaling surrounded by a ring like border
• Named after the site
  • Tinea capitis:  ring worm on the scalp (inflamed lesions may also occur)
  • Tine pedis:  itching is the most common symptom, infection looks like a moccasin that spreads beyond the plantar surface with scaling and fissures between the toes
  • Tinea Cruris (jock itch or crotch rot):  itching once again the most common symptom with red annular patched on the inner thighs
  • Tinea Faciei:  characterized by a papulosquamous rash with large scaling plaques.  The lesions can be vesicular, eczematous, pustular or granulomatous and secondary lichenification can occur (due to people rubbing and scratching at the lesion)
    • Scarring can occur from inflammation (animal causes are the most inflammatory in nature)

• Most common type is distal/lateral subungal
• Starts with the fungus penetration the stratum corneum through the nail fold or hyponycial aread
• Causes an infection under the nail that resembles melanoma (the fungus produces a pigment)

4. Candidiasis

• Characteristics:  moist red, scaly patches that are surrounded by satellite papules and pustules
• Most common sites are anywhere where skin overlaps skin (groin, axillae, gluteal folds, interdigital spaces, under the breasts)

5.  Deep fungal infections (coccidiomycosis, histoplasmosis, cryptococcosus)

• Usually skin disease is a result of an overwhelming pulmonary infection that has spread to the skin (almost never solely infects the skin)
• Not spread person to person
• Limited to geographic distribution
• Coccidiomycosis:  have to be concerned about arthrospores in the air (Arizona, valleys of California, and areas of Mexico)

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