I like to think of Stacy London, the co-star of TLC's What Not to Wear, as a modern-day superhero, who emerges from hardship with that thing that's acutely special. Peter Parker got his Spidey sense from a strange spider bite; Stacy London earned her style sense by shedding her skin, so to speak. That trademark silver streak ain't just cosmetic, folks. It reflects her raw transformation and, like the badge of any good superhero, symbolizes her personal past and power in becoming, shall we say, "Stacy London: Style Genius."

In her book published this month, The Truth About Style, London departs from the snarky diva she plays on TV to disclose how her own image has haunted her—a battle that took hold of her in sixth grade. That's when London suffered a severe bout of psoriasis, a skin disease in which the body overproduces skin cells. In her case, red, itchy, sometimes bleeding, scales blanketed her body and caked her scalp, which she says resembled peanut brittle. Every night, she would slather her scalp with tar, and every morning, her mother would scrub the solution loose with boric acid. Eventually, this got so tiresome that she had her long locks shaved for a crew cut. "Getting my hair cut like that didn't just make me feel less girly—it made me feel less human," London writes. It didn't help that The Elephant Man, a movie about a deformed man, came out that year, and London's classmates stuffed notes in her locker calling her uglier than the title character. She spent the year in a turtleneck and long pants, no matter the season. She did not allow herself to be photographed.

Eventually, London found a solution in one of the many ointments her parents toted around from the dermatologist. After a dab of it cleared a patch by her elbow, she smeared it on the rest of her body. It erased the scales but, in their place, something else emerged. The ointment was so strong that it thinned her skin, which began "tearing like a zipper," leaving purple fissures and scars all over her body.

When her hair grew back, the silver streak emerged—maybe as a result of the stress or the harsh treatments. She was 11.

In the book's first chapter, entitled "Learning to Shed My Skin," London introduces her story with a quote by Carl Jung: "Only the wounded physician heals." The idea, of course, is that having grappled with her own image and ultimately accepting herself (the last chapter is called "Getting Comfy in My Skin) enables her to understand and help others.

Indeed, London tells her story by the particulars of nine women she features in this book. She selected them, as she notes in her interview with U.S. News, because they battled so many of the issues that plague all women, and because London relates so well to them. For example, Ashley, a 19-year-old University of Texas medical student, lost 100 pounds and gained back 50 in the wake of her boyfriend's infidelity. In this chapter, London discusses how her own battle with anorexia followed by binge eating caused her to double her weight (from 90 to 180 pounds) in the year after graduating from college. London draws on the "beauty and bravery" of a friend who dons black leather and a Mohawk in the face of cancer to help Janis, 60, determine how to dress her restructured breasts.

Through these examples, we see the ways that people use clothing to mask their body or emotional distress. In fact, London argues that such attempts go far awry, telegraphing the opposite of what we intend. Instead, it's accepting one's self, exactly as one is at that moment that leads to dressing well and feeling better. London borrows an expression used in improv by a friend of hers, known as "Yes ... and." What it means is you take what you're given and add to it. When it comes to styling oneself, London suggests taking a long look at your naked self. Once you accept your body, then you can dress it. That's not an argument for complacency, but it's meant to encourage people to wear what fits them today, not six months ago or six years from now.

And yet, style has its place—well below the stature of character, London says. But she warns against underestimating the power of style to trigger personal transformation. When people see themselves differently, they can reclaim themselves, and even let go of the long-held stories or roles they use to define themselves, she explains. "What is magical and mystifying to me about style is not that by seeing we can believe. It is that eventually, we can believe, because we can see ... we can embrace change the more we can make it tangible."

London draws on this sensibility along with her personal struggles to coax others on the path to self-acceptance. In turn, the experience has a rebound effect. "Allowing them to accept themselves has really helped me so much in my acceptance of myself," London tells U.S. News.