By Alex Tresniowski
January 24, 2005 12:00 PM

How lucky can you get? That’s what John and Tara Blocker figured when their then 2-week-old baby daughter Ashlyn developed a diaper rash so terrible it hurt just to look at it. Miraculously, here she was with an awful inflammation, and still this sweet child—who always slept through the night and never cried—was acting like nothing was wrong. Recalls Tara, 33: “We took her to the doctor and we were like, ‘Wow, we have the happiest baby in the world because she’s not even affected by this.'”

It wasn’t until a few months later, when Ashlyn’s left eye became bloodshot, that the Blockers began to worry. “We gave her eyedrops, but she wasn’t getting better,” says Tara, a homemaker. “My mommy instincts just kept saying, ‘Something’s not right.'” Sure enough, an ophthalmologist discovered a massive corneal abrasion, a condition normally so painful that even an adult would be howling. But not Ashlyn.

After further testing, doctors eventually determined that she suffers from a condition called Congenital Insensitivity to Pain with Anhidrosis, or CIPA. Incurable, untreatable and so rare that only 35 cases are known in the U.S., CIPA makes Ashlyn completely unable to sense pain or extreme temperatures—and thus utterly vulnerable to a wide range of injuries and infections. “When people hear about it, they’re like, ‘Isn’t that a good thing?'” says Ashlyn’s father, John, 32, a telephone technician. “We say, ‘Just take a moment and think about it. Pain is there for a reason.'”

Think of a child who slams into walls and shrugs at the blood on her face; think of a girl who, as a toddler, absent-mindedly bit her skin just for fun. That’s Ashlyn. Now 5, she has badly burned her hand by leaving it on the muffler of a gas-powered motor, had her fingers crushed in a door frame and, on one horrible occasion, walked into the Blockers’ home in rural Patterson, Ga., and announced she couldn’t get the dirt off her skin. “It wasn’t dirt,” says her father, cringing at the memory. “It was hundreds of fire ants biting her.” Ashlyn has badly bitten her tongue, cheek and lips, causing so much damage that when she began knocking out her front teeth—by crashing into walls or biting down on a bottle—her parents were actually relieved. “It was,” says Tara, “a blessing in disguise.”

But even if Ashlyn is at times a danger to herself, she is a delight to her family, doctors and teachers. At the Blockers’ five-bedroom country-style home in tiny Patterson (pop. 627), she darts from room to room, scoops up Princess, her 4-month-old Chihuahua-Jack Russell terrier mix and shoots baskets in the driveway. Only recently has she begun to comprehend that she is different from her friends. “I can’t feel my boo-boos,” she explains matter-of-factly, distracted by the barrette she clips to the mane of her My Little Pony doll. Other children—like her brother Dereck, 7, and sister Tristen, 2—tend to tire out more quickly than Ashlyn, who never seems to slow down. “She’s like the Energizer Bunny,” says Beth Cloud, the nurse at Patterson Elementary School, where Ashlyn is in kindergarten. “She is precious, but she goes headfirst into everything.”

From the beginning, Tara and John Blocker have had to strike a delicate balance between protecting their child’s safety and offering her a normal childhood. As a toddler, Ashlyn did so much damage to her hands that her parents had to wrap them in athletic tape. “She looked like a little boxer,” says her mother. Even so, “we don’t want Ashlyn to live in a bubble,” says Tara. “We’ve learned what to worry about and what not to worry about, and we give her her space.”

After considering homeschooling, the Blockers opted instead to enlist the help of the staff at Patterson Elementary. There, Ashlyn’s teachers downplay the special measures designed for her benefit. Ashlyn is at risk of overheating during the day, so she gets a water bottle at her desk—and so do all the other kids in her class. A teacher discreetly feels her forehead several times a day to check for fever, and after recess she stops by nurse Cloud’s office for a thorough checkup. “They get the sand off of her feet, wash her eyes and treat any scratches,” says Tara. “I call it her NASCAR pit stop.” As for teasing from the other kids, once a little boy jabbed Ashlyn in the arm with a stick to see if she would react. “It wasn’t mean,” says teacher’s assistant Sue Price. “It was like his little science experiment.”

Almost certainly, Ashlyn’s medical problems will multiply as she ages. CIPA, caused by a genetic mutation shared by both her parents, results when a particular type of nerve cell fails to develop normally. The absence of pain makes her brain slow to respond to injuries, which can take twice as long as normal to heal. Damage to the joints is typical, since people with CIPA unknowingly put weight on injured ankles and knees. “In the next 10 years this is the most important problem Ashlyn will face,” says Tokyo pediatric neurologist Dr. Kenji Nihei, one of the world’s leading CIPA experts (see box). “Many patients become unable to walk.”

Some doctors say CIPA sufferers may also experience emotional problems. Someone as fearless as a child with CIPA could grow up to make bad judgments and take harmful risks—such as reckless drug use—or, in the other extreme, become excessively cautious. Still, “kids with all kinds of sensory impairments do very well,” says Dr. Lawrence Shapiro, an internationally known child psychologist. “There’s no reason to think she won’t have a normal life.”

So the Blockers will continue to make hard choices for their daughter, at least until she can make them for herself. “She wants to be a ballerina,” says Tara wistfully. Because of the harm that could do to her joints and bones, her parents will push swimming instead. Teaching Ashlyn to detect the signs of infections like appendicitis will be difficult—recently she had tonsillitis that went undiagnosed for six months—but Tara and John are heartened that she now knows to find her mother when she sees blood and has learned to ask if her food is cool enough to eat.

And most days Ashlyn could hardly appear more ordinary. “She’ll cry when she gets her feelings hurt or a toy gets taken away,” says John. “And she can feel tickles and hugs and kisses,” says Tara. “She’s got the best laugh in the world.” For the moment, her parents hold onto the hope that this fearless girl with the missing front teeth will have a remarkable life. Still, if they had but one wish for their daughter, it would be this: “I would give anything, absolutely anything,” says Tara, “for Ashlyn to feel pain.”

Alex Tresniowski. Kristin Harmel in Patterson and Nobuko Matsushita in Tokyo