Monday, May 10, 2010

Tinea Pedis

Is a fungal infection of the skin that causes scaling, flaking, and itch of affected areas. It is also known as Ring Worm or Athlete's foot.

Symptoms
The symptoms of athlete's foot or tinea pedis typically include itching and burning of the feet.

The skin may peel or crack with or without any associated pain.

Commonly the rash is localized to the soles of the feet.

Sometimes the flaking skin may spread to the sides and tops of the feet in a moccasin distribution.


The digital interspases may have some moisture, peeling, redness and flaking as well.



Types of Tinea Pedis


T rubrum is the most common cause for tinea pedis.

Trichophyton mentagrophytes, and Epidermophyton floccosum are other causative organisms.




Vesicular tinea pedis-
Usually caused by T mentagrophytes.

This type is characterized by painful, pruritic vesicles most often on the instep.






Interdigital tinea pedis-
Usually caused by T rubrum seen more in hot/ humid environments

This type is characterized by redness, maceration, fissuring, and scaling between toes. It is also associated with itching





Chronic hyperkeratotic tinea pedis-usually caused by T rubrum.
This type is characterized by chronic redness on the bottom of the foot or sides with scaling.




Risk Factors

  • A hot, humid, tropical environment
  • Prolonged use of footwear
  • Hyperhydrosis- Sweating
  • Certain people may have a genetic predisposition to the infection


Work Up

In suspected tinea pedis a KOH (potassium hydroxide) staining may be ordered by the doctor for fungal detection by obtaining a sample of the flaking skin

Fungal culture- may be performed to confirm the diagnosis of tinea pedis. A culture can be used to identify the fungal species.



Treatment

Tinea pedis can be treated with topical or oral antifungals. Some topical medications are over the counter. Topical agents are generally used for 1-6 weeks


Examples of Topical Medication

Topical Imidazoles

  • Clotrimazole 1% (Lotrimin)
  • Econazole 1% cream (Spectazole)
  • Ketoconazole 1% cream (Nizoral)

Topical Pyridones
  • Ciclopirox 1% cream (Loprox)

Topical Allylamines
  • Naftifine 1% cream (Naftin)
  • Terbinafine (Lamisil)

Oral Antifungals

Considered in patients with extensive chronic hyperkeratotic or inflammatory/vesicular tinea pedis
  • Terbinafine (Lamisil)
  • Itraconazole (Sporanox)

Prevention
  • Keeping your feet clean and dry
  • Avoiding prolonged moist environments
  • Disinfecting old shoes
  • Periodic use of anti fungal foot powder in the shoes

1 comment:

Anonymous said...

Nice post. Simple and clear.
Can you describe what kinds of illnesses might also contribute to the appearance of tinea? Can tinea cause any kind of lipoma or folliculitis type of formations under the skin?