OMAHA, Neb. -- A clothing tag on the back of a shirt is a scratchy annoyance to most people. But for up to 20 percent of the population, that tag causes a stabbing pain, so much that a person can't focus on anything else.

Melissa Irving-Gass noticed her 1-year-old, Keelan, was deeply troubled by clothing tags and many other stimuli.

"He wouldn't go anywhere near grass. He didn't like carpet. He didn't like different textures of baby food," Irving-Gass said.

The child also wasn't sleeping through the night and had tantrums that couldn't be calmed. In addition, he had language delays.

Keelan was diagnosed at age 1 with Sensory Integration Disorder. It's a disorder that causes the brain to misinterpret sensory input.

"When I started with Keelan, he wouldn't even touch grass," said Children's Hospital occupational therapist Karen Felderman.

She said 70 percent of her practice is devoted to young sensory patients who are often living with additional developmental disorders.

Felderman's therapy includes organized play to help patients work through their discomforts. Part of Keelan's therapy involves placing the boy on a turn table on the floor and slowly spinning him while he plays with puzzles or strings beads.

She also hands him items with different textures and praises him when he engages in the toy or follows her directions.

"Basically what you do is work with the senses they try to avoid and make it a normal state so the child can play," Felderman said.

Adding stimulus to play makes the child focus on the task at hand. Felderman cheers for the boy when he succeeds at stringing beads.

Irving-Gass also dug into a bin full of dry rice and beans, searching for plastic toys Felderman hid there.

"Basically it's going to feel like pins and needles, very noxious. It hurts when he first touches it," she said.

Felderman said children with the disorder will often gag on certain food textures, engage in rough play or have an emotional meltdown when they come in contact with typical childhood playthings like crayons or clay.

She said these children also have difficulty socializing.

Irving-Gass is now 3 years old and speaks with one or two words at a time. He communicates with sign language. Speech therapy is also part of his routine. His family has to avoid noisy parties or events where sights and sounds might overwhelm their child.

"I hope he's able to participate and the other kids don't say, oh, he's weird. I just want him to be a typical child," she said.

On a recent vacation, Irving-Gass sat Keelan in a field of grass and snapped his picture. Proof to Felderman that two years of therapy is paying off with a young boy who's beginning to find joy in simple play.

The boy is also living with Angelman Syndrome, a rare genetic disorder that makes it difficult for him to communicate and can cause developmental delays.