Hi Denise and welcome to the group!
Im so sorry youre having such a rough time with all of this. Your symptoms can be from mast cells, medication side effects or other conditions its hard to tell. You will probably have to treat this without knowing the exact cause, just symptomatically.

The exhaustion and pain on exertion is from the masto. Calf pain when you sit can be water gain or circulation problems--- that also can happen when you have a mast cell disorder.  You need to see your DR to know exactly which situation you are dealing with and which med will help.
Im sorry to hear about your arm and the crystalized mast cells--Ive never heard of it before but mast cells are pretty tricky things and pop out or take over any place they want to.

I am concerned about you being on Prednisone. I know its necessary to begin with (Prednisone temporarily calm the immune system and force it back to acting normal) but 3 months?? Youre gonna deal with some rough side effects if you cant get off of it--and that is hard. Your body makes 5 mg of natural steroids a day--that is in the adrenal gland.. Your body will stop making it as long as you take it and you can throw your body into adrenal crisis if you dont come off of it slowly and carefully--please make sure you do exactly what your DR says to when you stop the Prednisone.

I know the food restrictions suck.. you have a BIG need to be on safe food---UNTIL YOU ARE STABLE, then you can try 1 food every few days and add back the foods that you dont react to. You have to be stable first, you dont want to end up in the hospital. Just be careful Hon, and know we are all here for you!
Hugs
Ramona

Ramona's probably right, but you could try calcium supplements with magnesium, to see if it helps the pain.  I put epsom salts in my bath when I'm having cramping or muscle pain.

Are you on H1 and H2 antihistamines?  When I got on a therapeutic dose of them, taken twice a day, my pain went away.

The diet is hard.  

First of all, what's your dosage of H1 and H2 antihistamines and how many times/day?  Sometimes doctors prescribe too little to be effective.  Has your doctor mentioned ketotifen or gastrocrom?

Keeping a food and symptom diary might help.  Remember there are foods on the "avoid" list that you eventually may be able to tolerate, and there could be a food group that's allowed but might cause you symptoms (e.g., grains with gluten).  It's trial and error.  Keeping a food and symptom diary might help.

The guidelines are usually to eliminate everything on the "avoid" list for at least 2 weeks and then see how you feel.  I think a month is better.  Adding one food every few days will usually tell you if it's a problem.  Look at your diary and see if you can figure out what caused any symptoms you still have.  Also, some foods cross-react with allergens, for example, melons and ragweed, if you also have allergies.

Keep in mind that a food might bother you one day and not the next, because your "bucket" of mast cell triggers might be more or less "full."  When there are too many triggers, one little thing can cause it to overflow, i.e., cause you to have symptoms.  If it's not so full, you may be able to tolerate more.  Environmental changes, such as heat, weather changes, pollen and mold in the air, etc., can trigger symptoms, too.

As for pasta, check out the websites of Vegetarian Times magazine,  the Food Network, and AllRecipes.  They have many pasta recipes that use only allowed ingredients.  I googled "pasta sauce without tomato" and found a substitute sauce recipe for tomato sauce.  Don't know how good it is, though!  

Most vegetable pasta recipes without tomato sauce or aged cheese are fine or easily adjusted.  You can add meat or not, depending on your preference.  If it calls for bacon, you can substitute other cooked meat and add salt.  Try using crispy, salty, toasted fresh bread crumbs or bread cubes, tossed with a little olive oil, or toasted salted nuts instead of cheese.   

Broth can add flavor to a pasta dish, too.  Sometimes a sprinkle of finely grated lemon peel brightens the dish, especially broccoli and cauliflower.  Any recipe you use on pasta also can be used with rice.  You'll figure out substitutions, too, for example, lemon juice  for vinegar, swiss chard for spinach.  It's not all perfect, but amazing what you can learn to love!  Try to focus on what you CAN eat, rather than what's restricted.

Last thought, have you ruled out clots causing the pain?

The ICUS low histamine list allows lemons, limes, and grapefruits, but not oranges.  Don't know why!  Again, the diet is just a starting point.

If you haven't already done this, you might want to ask your doctor about other possible medicines, e.g., trying different H1 antihistamines, Singulair, gastrocrom, etc. to see if any of those help with the pain.  Some people have good luck with aspirin or naproxen, if they're not triggers.

I can't drink most teas.  They're on the ICUS "restricted" list, but coffee isn't.  Does anybody know why?