Dermatitis or Tinea?

One of the advantages of learning medicine is being able to self diagnose one's problems. One of the advantages (?)of Army medicine is that we experiment on one other to learn. Just as we once practiced IV's on one another until we could no longer recognize our appendages, we've also continued this Frankenstein experimenting in the labs. I've looked at my buddy's glowing, body-building-supplement, radiaoactive urine; determined his blood type, white and red blood cell count, etc.; and attempted to grow whatever we can find on each other's body in a petri dish just for s**ts and giggles. Most recently, I allowed my buddy to take a skin sample of a rash I've had on my back for months now to rule out any kind of tinea (fungal infection). It has never really hurt or anything and hasn't spread, so I figured it was some contact dermatitis, but I have yet to figure out what exactly has caused it. Nothing has been able to make it go away, so I thought it'd be good to confirm my suspicions about this only being some simple dermatitis. So, we scraped some skin from the site and took a look under the scope- whew- no fungi present, just dead skin cells. So that means that it's probably a certain fabric, or detergent, or maybe just the weather or water in the barracks causing the irritation- who knows? Tomorrow we'll look at some Staph and Strep bacteria, as well as do another urine sample. Sound like fun? The only bad part is the headache from looking through a microscope all day, and of course, the smell. GO ARMY!