The singer says her throat "pretty much closed" after eating a tomato.

By Julia Guerra
Ariana Grande performs onstage during Ariana Grande Sweetener World Tour at Staples Center on May 07, 2019 in Los Angeles, California
Credit: Getty Images/Kevin Mazur/Contributor

Ariana Grande is officially saying "ciao" to tomatoes. The pop star recently discovered she has a food allergy to the Italian staple, and her reaction has left her so sick that she's had to postpone some of her Sweetener World Tour dates.

The "7 Rings" singer first shared the news of her postponed tour dates on Tuesday, but the details of her illness were vague at the time. "I woke up incredibly sick today, ran to my doctor here and have been told to postpone these shows tonight and tomorrow. I'm so beyond devastated," she wrote on her Instagram Stories, according to Billboard. (Related: Ariana Grande Shared a Brain Scan Showing 'Terrifying' PTSD Trauma)

It wasn't until Wednesday that Grande found out what was making her sick. "Update: we discovered ..... that ..... i had an unfortunate allergic reaction to tomatoes and my throat pretty much closed. still feels like i'm swallowing a cactus but slowly making progress!" she shared on Instagram.

"Thank u all for your love and understanding," Grande continued. "Can't wait to get back to performing and to make it up to Tampa and Orlando in November. p.s. there is NOTHING MORE UNFAIR THAN AN ITALIAN WOMAN DEVELOPING AN ALLERGY TO TOMATOES IN HER MID TWENTIES......."

ICYDK, it's definitely possible to develop a food allergy later on in life, says Tania Elliott, M.D., a board-certified allergist and Flonase spokesperson. However, it isn't particularly common—which is a bummer for Grande, but good news in general. (Related: The Best Way to Address Your Food Allergies at Parties and Other Social Events)

Food allergies are most common in children, but they affect about 2 to 4 percent of adults as well, explains Elliott. Surprisingly, adult-onset food allergies are typically found in women, she adds. "Some theorize that it is due to fluxes and changes in estrogen levels in the body, although the exact mechanism is unknown," shares Dr. Elliott.

Generally speaking, allergies happen when your body's immune system reacts to what it thinks is a foreign, harmful substance. A food allergy happens when that "foreign" substance is, well, a food, explains Katie Marks-Cogan, M.D., chief allergist and co-founder of Ready, Set, Food!.

Basically, your immune system is set up to defend and protect your body from foreign invaders, like certain viruses and bacteria. With food allergies, your immune system is over-defending the body. It treats certain proteins in foods as foreign invaders, and these proteins (aka allergens) cause the immune system to make special allergy antibodies to help fight them off, says Dr. Marks-Cogan. "These antibodies assist us by causing a reaction each time a person eats a food they are allergic to," she explains.

Allergic reactions aren't subtle, either. If you're allergic to a certain food, you'll know by your body's reaction, says Purvi Parikh, M.D., allergist/immunologist with Allergy & Asthma Network. (Related: Can You Give Yourself a Food Intolerance?)

"Almost always there is a skin symptom such as itching, rash, swelling, which can be accompanied by nausea, vomiting, diarrhea, breathing problems like cough, wheeze, shortness of breath, or even chest tightness," she explains. All of this can happen within 30 to 60 minutes of contact with the allergen, adds Dr. Parikh.

Thankfully, it sounds like Grande's on the road to recovery from her allergic reaction. While it's unfortunate that she has to give up one of her biggest "food obsessions," she's made it crystal clear she's not giving up on her fans as a result.