Problem singer Ariana Grande has a health problem to fix.

A tomato allergy has sidelined her, forcing her to cancel shows in her Sweetener World Tour, she posted on Wednesday (May 29).

She revealed that "my throat (feels) almost closed" and that it "still feels like I'm swallowing a cactus".

Her food allergy is uncommon, with adults usually affected by consumption of items such as shellfish, milk, peanuts, soy and sesame.

Grande, 25, who is of Italian descent, will have to steer clear of dishes like spaghetti which uses tomatoes.

The thought of giving such familiar heritage fare a miss prompted her to post that there is "nothing more unfair than an Italian woman developing an allergy to tomatoes in her mid-20s".

Her fans have reacted with a dollop of humour, saying they will also boycott tomatoes.

But they are throwing rotten tomatoes at Madame Tussauds in London, upset over a wax figure of Grande which does not do her justice.