Can anyone tell me what they think these symptoms indicate?

she should get a blood test...

A rash that spreads when scratched could be scabies. Also, it could be allergy and as she scratches, she is spreading the allergen and it's histamine to the outlying parts of her skin. Allergies will cause shortness of breath and the swollen lower extremities--she needs to see an allergist or go to EMR--this is affecting her heart! Has she been stung by a bee? Some allergic reactions can go on for months, and they get worse--the system runs down, the heart weakens. She sounds like she is actually in crisis situation, and it's hard to figure out what may be causing the reaction--particular allergies can be hard to pinpoint. She needs to be treated quickly for her present condition/reaction, and followed up closely to pinpoint the specific allergen.

The two things may be unrelated. It still may be an allergy. But shortness of breath and swelling may be signs of some type of venous problem. It can cause the lower extremity (usually lower leg) to have redness. If I were their doctor, I would look into: Diabetes (can also have these symptoms), hypothyroidism, and heart valve function.

those indicators could certainly be certainly one of a million issues! although, the situation that sticks out for me is thyroid problems. I truthfully have an underactive thyroid, and in the past i became "clinically determined", I had many of the indications you defined. Now all I do is take a pill on a daily basis and issues are super. If I have been you, i could incredibly discover out--all it takes is a user-friendly blood draw to confirm. sturdy success!

maybe shes allergic to something? thats some of the symptoms, but you will just have to check what shes using or eating to see if anything makes the scratching and other things worse.