It sure does sound like an allergy to me Wiz.

Are you allergic to Penicillin perhaps? I ask, because often people who are allergic to the penicillins are often allergic to the sulphas as well.

Here's a list of the side effects of Sulphas (and Bactrim is a Sulpha drug).

More common side effects may include:

* Hives
* lack or loss of appetite
* nausea
* skin rash
* vomiting

Less common or rare side effects may include:

* abdominal pain
* allergic reactions
* anemia
* chills
* convulsions
* depression
* diarrhea
* eye irritation
* fatigue
* fever
* hallucinations
* headache
* hepatitis
* inability to fall or stay asleep
* inability to urinate
* increased urination
* inflammation of heart muscle
* inflammation of the mouth and/or tongue
* itching, joint pain
* kidney failure
* lack of feeling or concern
* lack of muscle coordination
* loss of appetite
* low blood sugar
* meningitis (inflammation of the brain or spinal cord)
* muscle pain
* nausea
* nervousness
* red
* raised rash
* redness and swelling of the tongue
* ringing in the ears
* scaling of dead skin due to inflammation
* sensitivity to light
* severe skin welts or swelling
* skin eruptions
* skin peeling
* vertigo
* weakness
* yellowing of eyes and skin

Ref: http://www.inhousepharmacy.co.uk/inf...-patients.html

The rash worries me, and my advice would be to stop taking the Bactrim and contact your doctor. It sounds like you may be allergic to this medication.