(RxWiki News) People with a mysterious skin condition are eager for doctors to pinpoint a cause. Based on a new study, researchers may be able to strike one potential source of the irritation.
In a recent study, there did not appear to be a link between food and drug additives and chronic idiopathic urticaria (CIU).
Doctors are not clear on what causes CIU, which is a condition generally marked by body hives that recur most days of the week for more than six weeks.
"Consult a dermatologist about any persistent skin inflammation."
Jessica P. Rajan, MD, of the Division of Allergy, Asthma and Immunology at the Scripps Clinic in San Diego, Calif., led this research.
Dr. Rajan's team tested 100 patients already diagnosed with CIU by giving them 11 additives, including common food dyes like Yellow 5 and Yellow 6, and preservatives, such as monosodium glutamate (MSG), which is widely used in Chinese cooking.
All of the study's participants had a history of CIU for longer than six weeks, and 43 of the 100 reported possible history of food or drug additive sensitivity.
Dr. Rajan found that only two participants showed an urticarial response, meaning their condition worsened. No patients reported effects later.
The researchers concluded that sensitivity to the 11 additives tested occurred in less than 1 percent of patients with CIU.
Dr. Rajan’s study showed that because sensitivity to additives appeared to be a rare contributor to CIU, there may be no need to avoid these common ingredients.
All of the additives tested were: Yellow 5 dye, Yellow 6 dye, potassium metabisulfite, monosodium glutamate, aspartame, sodium benzoate, methyl paraben, butylated hydroxyl anisole, butylated hydroxyl toluene, sodium nitrate and sodium nitrite.
This study was published in the March issue of The Journal of Allergy and Clinical Immunology: In Practice.
Dr. Rajan and her colleagues did not report any relevant conflicts of interest.
Funding was provided by the Scripps Clinic, a private, nonprofit health system comprising four hospitals and thousands of affiliated physicians.