'RHONY''s Jenna Lyons Is Afraid to Wear a Swimsuit on Vacation Because of Her Skin Disorder: 'Abject Terror' (Exclusive)

Jenna Lyons says strangers think she looks "dirty" without realizing she has a skin condition in PEOPLE's exclusive look at Sunday's episode of 'The Real Housewives of New York City'

Jenna Lyons is nervous about her upcoming vacation.

In PEOPLE's exclusive clip of Sunday's episode of The Real Housewives of New York City, Lyons, 55, tells her brother that she feels “abject terror" at the thought of wearing a bathing suit on an upcoming girls’ trip to Anguilla.

“I’m not going to be wearing a bathing suit. It’s not happening,” she says over drinks. “I’m literally going to be wearing, like, tweed pants and a blazer at the pool.”

The reason? “My skin,” explains the fashion designer. The former J. Crew president has the genetic disorder incontinentia pigmenti, also known as Bloch-Sulzberger syndrome — which affects the skin, hair and teeth, according to the National Institute of Neurological Disorders and Stroke.

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And for Lyons, it presents as bald spots, teeth that are missing or very small, and “discolorations all over my skin.” While it helped inspire her love of fashion, it’s also given her insecurities about her appearance.

The upcoming trip to Anguilla, she says, makes her think about her childhood in Palos Verdes, Calif.: “I'm back in my California-in-a-bathing-suit days.”

“Does it still bother you after all this time?” her brother asks. “Is that why you don’t want to do the bathing suit thing?”

Related: Who Is Jenna Lyons' Girlfriend? All About Cass Bird

“Yeah, totally. I don’t want to be in front of them. They all are gorgeous,” she says of her castmates. “I’m not being nice. It’s the truth.”

“A little off the mark,” he replies, but Lyons explains that exposing her body brings back bad memories of when she was a child struggling with people’s reactions to her discolored skin.

“I know it’s a genetic disorder but most people don’t, and people are like, ‘Oh, you’re dirty,’ or like, ’You have something on your skin,' and it’s like…I don’t actually want to deal with that.”

“I still remember going to [Buena Park, Calif., amusement park] Knott's Berry Farm, I was like, wearing shorts and standing in line, and some girl behind me going, ‘Ew, look at her skin.’ And I don’t really want to do that on a vacation,” the Love Seen creator says.

Lyons reveals that the way she tried to manage her condition in the summertime was to isolate herself.

“Every summer for as long as I could remember, I would like hibernate away from everybody else and get a tan, because when I didn’t, in the sun it really looks magnified.”

Related: ‘RHONY’ Star Jenna Lyons Recalls Being Outed Before She Was Ready: ‘It Was Shocking’

“People are always saying to me, ‘Oh what’s on your skin?’ Or, “Oh, do you have a burn?’ So getting a tan kind of quiets the visual noise and it makes me feel better.”

The new episode of The Real Housewives of New York City airs Sunday, September 3rd, at 9 p.m. ET on Bravo and is available on Peacock the next day.

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