Hello all,
I thought some of you may benefit from some interesting tidbits I have learned about azo dyes, after seeing azo dyes on the mast cell degranulators list.  I am sorry there isn't a fantastic website to references but wikipedia did get me started, the rest I have pieced together from scores of sites.  

I've also recently posted on food and medication colorings under Medications, but decided to start a new thread here under Triggers.  

The FDA gets the most complaints about 3 food additives - aspartame, FD&C Red 40, and FD&C Yellow 5.  All three of these can triger hives, flushing, headaches, congnitive impairment, itching and GI issues.  My research has been focused on food and medication dyes, since I already knew I didn't tolerate Yellow 5.

Any of the numbered dyes beginning with FD&C (USA Numbering system =Food, Drug and Cosmetic) are considered azo dyes.  Several of these numbered dyes have already been pulled from the US market due to research that proved they are known carcinogens.  These dyes are cheap to make and are derived from petroleum.   Europe and other countries have banned azo dyes.  

Red and Yellow Azo dyes are high in salicylates.  A comprehensive list of products and foods containing high salicylates in posted several places on this site.      

FD&C Red 40, also known as Allure Red, is found in red, pink, and purple medications, as well as products and foods.  It is used to add color to soda, such as rootbeer, marchino cheries, gatorade, koolaid, jello, ice cream, cereal, packaged foods, and is injected into tomatoes and other red produce as well.    

FD&C Yellow 5 is also known as Tartrazine, is lemon yellow in color and is found in medications as yellow, peach, orange, green, and purple tablets and capsules.  It is also found in products and bakery goods (breads, donuts, cookies, cakes) Mountain Dew and other sodas, spices, cereal, snack foods, such as Doritos, Cheetos, and just about every packaged food.   People who react to tartrazine tend to also have asprin sensitivity, tied to the high salicylates.  

FD&C Yellow 6 is also known as Sunset Yellow and is made from Tartrazine (FD&C Yellow 5), so many people also react to this one as well. It tends to look dark yellow or orange and is found in in many of the same items as above.

I've found the following meds contain either a red or yellow azo dye (different formulations and doseages may vary): generic ranitidine, brand Zantac, prescription 50K IU Vit D, generic zolpidem, verapamil, synthroid, Levoxyl, HCTZ, advil gelcaps.

Iron oxide dyes are one alternative to azo dyes.  They are more expensive, but widely considered safe, and the natural oxides come from the earth.  Fexofenadine (generic allegra) and Singulair both have an iron oxide dye.  Look for meds or foods with iron oxide dyes and avoid FD&C dyes if possible, then see if your level of reactivity changes.  

If you consider the bucket theory, it would make sense to limit these azo dyes from obvious foods and medications.  I am only 4 days into my azo-free program and others are noticing a change in me, so it must be lowering my bucket level.  I hope this may be able to help someone else lower their bucket level.  
Lyn

Lori,
Your welcome.  I got on a roll and found that at least 10 of my meds that I reacted to in the past contain red or yellow azo dyes.    

I did run across  black iron oxide dyes in certain meds (Target and Sam's Club) generic fexofenadine (Allegra) and saw this listed as a iron oxide dye color choice.  There is also a red iron oxide and yellow iron oxide in the meds I found.  

I would guess cake frosting contains a FD&C dye, meaning likely azo dye.  I'll keep an eye out for black and let you know if I find anything.  Carob works, huh?  

Lyn

I did my own sleuthing and had known that the Vyvanse I took for ADHD would make me itchy and have difficulty breathing, although not all the time (the bucket full theory) .  I complained to the doctor many times and he would say it was not the Vyvanse doing it.  The capsule shells (imprinted with NRP104) contain gelatin, titanium dioxide, and one or more of the following: D&C Red #28, D&C Yellow #10, FD&C Blue #1, FD&C Green #3, and FD&C Red #40. The capsule shells (imprinted with S489) contain gelatin, titanium dioxide, and one or more of the following: FD&C Red #3, FD&C Yellow #6, FD&C Blue #1, Black Iron Oxide, and Yellow Iron Oxide.

I realized this last summer and started dumping the contents out and eating it without the capsule.

Update on my quest to go AZO-free.  I have figured out that I am severely reacting to red 40 and yellow 5 and 6 dyes.  Several of of my meds contained them, so no wonder my bucket was full. Stopped taking azo dye filled antihistamines.  I am so careful about preservatives and MSG in my diet, but did have yellow birthday cake with whipped white topping (friend suprised me at a St Patty's get-together) so felt compelled to have a small piece.  I did gracefully turn down the Guiness chocolate cheescake.    She gave me the rest of the cake to bring home.  Tempted fate and had small piece on my b-day and within 10 minutes had serious flushing, big "D" and was puking.   Called the local bakery the next day and the owner confirmed yellow and red dyes in the yellow cake.  I knew enough to avoid the green icing, but thought I could handle a small piece of cake.  I "challenged" myself the next day with a drop of yellow food coloring on my tongue.  It set off a four hour reaction complete with a 3 hours of forced sleeping.  Lesson learned.  Yellow dyes are in most bakery items, except many artisan breads.  No wonder I can sneak limited  pumpernikel or sourdough without noticing any issues.  

Been researching these dyes and noticed red 40, yellow 5, yellow 6 all contain sulfa. My worst reactions are with meds that contain sulfa, including sulfonamide antibiotics and other sulfa meds that aren't usually linked with sulfa reactions.  I know they induce direct granulation, but I always wondered if my other intolerances were linked somehow.  After piecing together info on multiple webites, looks like azo dyes, food preservatives such as BHT, MSG, sulfites and sulfa reactions are linked to enzyme deficiency in 2nd pass liver detoxification.  Been reading a few allergy text books online and this linkage has been around since the 1990's!  

Still flushing on a daily basis, but had several decent days in a row since figuring out red 40 and yellow 5 and 6 were triggering my reactions.  Next week, may "challange" with the red food coloring.