Researchers in Germany have found a significant rise in allergy to propolis, also known as ‘bee glue.’
A study published online ahead of print in the British Journal of Dermatology (Feb. 27, 2020) analyzed 125,436 people tested for skin allergy between 2007 and 2018 across Germany, Austria and Switzerland and saw that skin allergy to propolis has increased by more than 60% since 2007.
According to the researchers, propolis has antibacterial, antifungal and antiviral properties and is found in health products, as a dietary supplement and as an ingredient in many cosmetic and skincare products. It is created and used by bees to construct their hive. Propolis consists of materials from living plants mixed with an enzyme present in the bees’ saliva, partially digested and added to beeswax to form raw propolis.
For the study, researchers gathered data from patients undergoing patch tests across 56 centres forming The Information Network of Departments of Dermatology.
The study's authors found that during the period between 2015 and 2018, 3.94% of patch-tested people were allergic to propolis, compared to 2.35% of people patch-tested between 2007 to 2010—an increase of 68%.
“Currently, propolis is not routinely included in patch testing in the UK, so the level of allergies here cannot be fully established,” said Nina Goad, head of communications for the British Association of Dermatologists, in a press release. “However, if trends in its use in the UK show an increase, a similar situation would be expected in our allergy clinics.
“While there may be benefits to natural skincare products, it should not be assumed that they are safer for the skin than their non-natural counterparts. If you experience a skin reaction, do not rule out a natural skin product as the culprit, and let your doctor know about anything that your skin has been in contact with.”
Contact allergy develops when the skin comes in contact with allergens causing sensitization. If the skin is exposed to the same allergen again, it can develop an eczematous reaction known as allergic contact dermatitis.
Propolis is an ingredient found in a wide variety of cosmetic products including shampoos, conditioners, ointments, lotions, lip balms and toothpastes.
“The increase in allergy to propolis that we have observed certainly warrants targeted investigation of what is driving sensitization,” said Dr. Wolfgang Uter, the lead author of the study. Dr. Uter is a professor in the department of medical informatics, biometry and epidemiology at the University of Erlangen/Nürnberg in Erlangen, Germany.
“At present, we do not know the full extent of its availability and how widely it is used. If the allergy trend continues, we will need to consider a reassessment of risk, and probably risk management such as a limit on the concentration of propolis allowed in products that are left on the skin.”