According to Daniel Watter, a sex therapist and clinical psychologist in New Jersey, the clinical definition of a fetish has a pathological component as well.
"In order to be a diagnosable thing, that interest has to create some distress within the person or inability to work or live their life in some way," Watter said. "The element of being distressed is crucial."
A fetish can disturb a partnership if it becomes the primary focus of a couple's sex life. DeVillers described a couple she knew who engaged in bondage during sex.
"The man needed to tie up his girlfriend in order to be sexually functional," sex therapist DeVillers said. "She went along with it. She probably found it fun."
But bondage and sex became too intertwined in the couple's love life. Unless she was tied up, the man was not interested in his girlfriend, and she began to feel unattractive and unhappy, DeVillers said.
"Is it healthy to have creative, playful variety in your sex life? Yes," DeVillers said. "When it becomes very ritualized, it isn't so much fun as mandatory and odds are it's not ultimately going to be as satisfying."
Information on fetishes is limited because people only seek help when they are in distress. It is unlikely that a penchant for sneezing is going to hamper a person's life significantly and many experts have never even heard of such a fetish.
"If it hasn't come to any professional's attention, that must mean it doesn't disturb the partnership," said Aline Zolbrod, an author and lecturer on sexuality.
One poster on Sneeze Fetish Forum was not distressed at all by her college roommate's allergies: "It really seemed like everything made her sneeze, which did make me happy."
In lieu of expert guidance, many people, including those with a sneezing fetish, refer to the Internet for information. Sites such as Sneeze Fetish Forum and Tarotgal (now defunct, but still a source of information, stories and art), as well as Yahoo groups dedicated to sneezing offer a place where itchy noses and their admirers can gather to share stories, experiences and advice.
The shared experience of the fetish community makes for strong bonds, especially because fetishism was traditionally considered a kind of paraphilia, or a behavior that is beyond normal.
But the idea that fetishes or kinks, a looser term that means a person likes variant behavior, are beyond normal is giving way with people questioning the boundaries of what's "normal." Oral sex and masturbation were once considered deviant behaviors. Now many consider them mainstream; staples of a sexual repertoire.
"There's fetishes in every size, shape and color," Ruppel at the Institute for Advanced Study of Human Sexuality said. "If something is rewarding to us and feels good to us at certain points in our development, we imprint it into our development. ... There is diversity in sexuality."