What a coincidence Foodnfoto!
I recently wrote on that subject in my column:
Recently, a college student approached me to ask if I knew of any allergic reaction to mangoes. She explained that the lips of her boyfriend immediately became inflamed and severely blistered after eating a piece of mango. The next day the irritation had caused excessive chapping, peeling and even swelling. A visit to a drugstore, she related, was unfruitful for answers or remedies. At the time she was asking me about it, her boyfriend’s lips were still swollen and covered with scabs. To her chagrin, a slight grin would make him bleed. During our discussion, she mentioned this was not the first time he was exposed to mangoes because he often drinks mango juice without any adverse affect. Food allergies can manifest themselves mildly or acutely to the point of being life threatening as in anaphylactic shock. So why did his lips reacted in an allergic fashion now but never his digestive tract beforehand. The whole body reacts to an allergen including the skin as the scratch test demonstrates. I was stomped to explain this. Since I am neither a medical doctor nor do I play one on TV, I advised the student to seek medical help. On my part, some research was required to understand this conundrum.
A quick web search revealed that the mango tree belongs to the Anacardiaceae family of plants who’s members include Toxicodendron a.k.a poison ivy. These plants produce urushiol in their sap, a powerful skin irritant probably used as a defence chemical agent against munching pests. It’s believe that 70% of humans are sensitive to poison ivy sap hence probably mango tree sap. Since only the sap contains urushiol not the fruit, eating mangoes is not a threat unless it has some sap residue on it. Obviously this is a plausible explanation which explains the conundrum. I relayed this information to the student in question. In light of this information, her boyfriend recollected he once was in contact with poison ivy which caused a severe skin reaction. She also confirmed that the culprit mango was prepared unpeeled without washing it.
Urushiol induced dermatitis treatment involves washing the affected area immediately with soap and water to wash away the oily irritant. Antihistamine medication or a hydrocortisone base cream are effective to reduce the skin reaction which is similar to an allergy. Also, anti-itching or anti-burning medications like calamine lotion and Aloe vera can help soothe the discomforting skin irritation. Let’s not forget, washing your fruits is a good idea!>