Complications include:
* Allergic reaction to the dye;
* A feeling of light nausea that may be accompanied by perspiration when the contrast dye is injected;
* A small pea- or acorn-sized bruise, knot, or lump at the insertion point;
* Bleeding; and/or
...

Complications include:
* Allergic reaction to the dye;
* A feeling of light nausea that may be accompanied by perspiration when the contrast dye is injected;
* A small pea- or acorn-sized bruise, knot, or lump at the insertion point;
* Bleeding; and/or
* Swelling, pain, numbness, redness, or drainage at the insertion site.

People who experience any of these symptoms should call their physician as soon as possible.

And yours sounds worse that usual.

You may be unsuited for CT angiography if you:
Have an allergy to contrast dye;
* Have kidney problems;
* Have severe diabetes;
* Are pregnant, because radiation may harm the fetus;
* Have unstable vital signs; or
* Weigh more than 300 pounds, because some x ray tables cannot support th...

You may be unsuited for CT angiography if you:
Have an allergy to contrast dye;
* Have kidney problems;
* Have severe diabetes;
* Are pregnant, because radiation may harm the fetus;
* Have unstable vital signs; or
* Weigh more than 300 pounds, because some x ray tables cannot support the weight.

The most serious early complication of CT angiography is an allergic reaction to the contrast dye. Reactions usually occur immediately and include flushing, itching, or, rarely, difficulty breathing or swallowing.

Sometimes contrast dye leaks under your skin at the injection site. This can cause redness, swelling, or pain. The contrast dye can also damage kidney function depending upon the amount of the dye used and whether you have any kidney problems that already exist.
Notify your physician since you are experiencing above mentioned symptoms as soon as possible.

Call your physician and/or speak with his nurse - this is free of charge! They may advise you to put warm compresses on the "knot". They may want to see you. Any way you look at it, it's painful and large - the doctor needs to know. The solution may very well be only a phone call away - why put yourself through the discomfort.