My sister ate Thai food 3 days in a row (Fri, Sat, Sun). On Monday morning she had an itchy rash and face that looked like she had been hit (red, swollen, hive type rash). Over the next 4 days the rash only got worse. It moved from head to chest, to legs, all over her body – a different spot every day. Antihistamines had no effect. Eventually she went to the Emergency Department and a doctor thought "not food related" but a nurse suggested it might have been.

They prescribed a corticosteroid (I think) which began to make an impact. But reading the info on your website re ribo rash - it all made sense.  She has since noticed the rash on a smaller scale after eating CC's with 621 and 635. – by email, Vic [The 635 in Thai food can be in the soy sauce or fish sauce]