I am a firm believer in listening to what the body is telling you.
When something is wrong and it is unhappy, it lets you know with symptoms, both mental and physical.
When it is happy, it serves you well makes you feel pleasant. :)
Chlorella is hot money maker on the market at this time!
If you are showing an allergic reaction such as hives or throwing up, I would suggest you discontinue the use of chlorella. The same goes for gas, cramps or bloating in the intestines.
If there was a history of childhood cholic, alergic skin rashes or asthma in my family, I would not use chlorella.
Chlorella is high sulfur. If your body is already high in sulfur, adding too much sulfur could have adverse effects if you have impaired sulfur oxidation. Some people have an impaired ability to oxidize and detoxify sulfur compounds. This is well known by the inability to safely process sulfa-drugs. A buildup in the body of excess sulfur compounds can be uncomfortable and even life threatening.
More about Impaired Sulfur Oxidation here: http://www.cfsn.com/sulph.html
Other than that, sulfur is great for the body.
You said: -->"" I'm not sure if I should stop talking it, or if maybe something else is causing these hives.""
All I can say is if "it's your thing...do whatcha wanna do".
Only you can decide what is right for you.
I will list sulfur rich foods at bottom of this message.
I suggest using cilantro. I think it is the most powerful natural chelator of mercury and toxic metals in the body.
Foods Rich in Sulfur
For those of us with impaired sulfoxidation, knowing what's high in sulfur is critical.
Garlic, onions, and all of the allium family
methionine: corn, sunflower seeds, oats, chocolate, cashews, walnuts, almonds, sesame seeds (in that order).
cysteine: oats, corn (corn grits are higher than chicken, see Sulfur in Human Nutrition and Applications in Medicine, by Stephen Parcell, ND. Published by Thorne Research. [PDF].)
Legumes (alfalfa: MSM)
[of duck maybe less so?]
Nuts & seeds
Broccoli and all cole-family (brassica) vegetables. This includes cabbages, pak choi, mustard, and watercress.
Avocado (high in glutathione, which breaks down during digestion, yielding cysteine)
Watermelon (also high in glutathione)
Spinach (high in lipoic acid)
Sweet potatoes and "yams" (American yams, Genus Ipomoea, not Dioscorea, which the rest of the world calls "yams") - a sulfur compound in this tuber chelates heavy metals. [Need documentation on this.]
Tea & coffee: MSM
Cows' milk: MSM
Whey proteins (high in cysteine & methionine)
Amino acids: cysteine, methionine
Thiamin / Thiamine / Vitamin B1 / aneurine
Biotin, Vitamin B7 or Vitamin H http://www.canarys-eye-view.org/challenges/food/sulfurfoods.html