A United passenger says she was 'humiliated' by a supervisor who wouldn't alert other travelers to her son's 'life-threatening' peanut allergy

• A United passenger says an airline crew member refused to accommodate her son's peanut allergy.
• Lianne Mandelbaum said she was "dressed down" after asking for passengers to be told of his allergy.

A United Airlines passenger says she was left "humiliated" after a cabin crew member refused to inform other travelers of her son's life-threatening peanut allergy.

Lianne Mandelbaum boarded a flight from Houston to Newark in March with her husband and son, Joshua, according to a complaint to the Department of Transportation.

She said she asked a flight attendant to inform passengers located in her immediate vicinity of her son's peanut allergy. After some confusion over the request, Mandelbaum told the crew member she had made the same request on another United flight two days earlier.

Before takeoff, Mandelbaum says she was summoned to the front plane by a United supervisor, who said her request had been denied.

According to United's website, passengers with a severe food allergy are encouraged to inform a flight attendant and to request an "allergy buffer zone" by alerting nearby passengers. However, it says it can't stop passengers from eating allergen-containing products.

Mandelbaum showed the supervisor the guidance on the United website, but says she was met with a hand being put up to her face.

"Ma'am, I don't care what you are trying to say, I am telling you this will not happen on this flight so what do you want to do now," Mandelbaum said she was told, adding she "truly felt threatened" by the supervisor's tone and body language.

Mandelbaum told Insider in a Twitter direct message that she gave up as she was afraid of being removed from the flight.

"It was clear to all the passengers in the vicinity that I was summoned to the front of the plane and that I was being dressed down," she said in her DOT complaint. "I was humiliated and treated as if my son's peanut allergy was not a legitimate disability and not worthy of respect."

When Mandelbaum complained about the incident on Twitter, United's account responded by directing her to the same guidance she said she tried to show the crew on her flight.

Mandelbaum is a food allergen campaigner and blogger who has previously spoken with The New York Times about navigating children with food allergies through airports.

She asked the DOT to fine United and order the airline to train staff over what she called a pattern of discriminatory treatment of passengers with food allergies.

Research by the Center for Food Allergy & Asthma Research found nearly one in 10 surveyed passengers with food allergies experienced a reaction while on a flight.

United didn't immediately respond to a request for comment from Insider, made outside normal working hours.