A little background:  A patient had a FA/ICG and had a severe reaction.  The physician is considering continuing with ICGs to help guide treatment.  I would like to determine which dye she had the reaction from before continuing with ICGs.  

The skin test for fluorescein sodium is a poor test - because the pH is so high, the skin is bound to react with pain, redness and inflammation, and a sub-cu deposit of fluoresecein will raise a welt just as TB tests do.

Per the literature, there is a MUCH greater chance of allergy to fluorescein than ICG.  The Iodine in ICG, which is nearly always considered the culprit in an allergic reaction, is not even a complete molecule, only an iodide (iodine ion).  I am certain you already asked if the pt had allergy to shellfish which are high in iodine.

I would think that ruling out allergy to ICG would be the better way to go.  A skin test for ICG will not be as painful or reactive, I don't think, as injecting fluorescein into the skin.  Based on what you said the Tx plan was, if ICG appears safe, then your physician could proceed with using it as efficaciously as possible. 

Since you work at a major academic medical center, I'll bet you have a drug review panel, "Ask a pharmacist" type entity, that could help you design a safe path to rule out the culprit.  If you do so, we would ABSOLUTELY POSITIVELY want to know what their recommendations would be!

Hope this helps,

Paula

In our office, I've only had an opportunity to test a patient with a 'questionable FA' dye allergy.  For this experiment, I put a small amount of FA dye on a band aide, and put it on the patients skin.

Then, shot my Colors, and RF's, and let the patient relax a bit, amongst their already high tension of emotions.  Within 10-12 minutes, we took off the band aide, and looked at their skin.  There was no reactivity, and so, she signed her consent form, and off we went.

Of note, and I'm no expert, regarding the ICG content of Iodine, of course we all know it is used as a preservative and not a component of the dye itself.  I'm sure you did your due diligence, and asked the patient if they had a 'seafood' allergy, and they probably responded no.  Nonetheless, it is in such micro molar amounts that it probably wouldn't have elicited a response, in this concentration, and hopefully your sentiments are the same.

Please let us know what your pharmacy department at UNC says, and I'll check in on this thread periodically.

 Thanks,

Jim

Depending on the reaction if it was severe hives, I would premed the patient with 25-50mg PO of Benadryl about 30minutes prior to FA. Some doctors would write a script for steroids and have them start it the day before the test.

In the clinic, I premed for previous reactions with 25mg IV Benadryl diluted with 2-4cc of sterile water. IV Benadryl tends to cause the arm to ache if not diluted well. I leave the IV line in for the full 5+ minutes of the test incase in need to add an additional 25mg IV Benadryl. I have had patients that cannot have FA due to severe reaction that causes itching in the mouth or throat. I will not perform a FA if this has happened. I have had good success with premed for itching and hives. 

We do have those patients that have severe vomiting every time they have an FA. Nothing will prevent it. I have tried antiemetics, Benadryl, and reducing the dose of the FA to 1cc. No matter what they violently vomit. They are far and few between.

Most that have had nausea and vomiting, tend to do well with me giving them 2.5cc of FA dye slow with a 10 to 15 second push. It reduces the severity of nausea or prevents it all together.  This works well with the Spectralis camera, but may not work for most fundus cameras.