It's unbearable to wear clothing with tags. It's impossible to use scissors, no matter how many times you try. All mushy or soft foods are unbearable - not because of the flavor, but the consistency.
Depending on whom you ask, it's either common childhood behavior, a neurological disorder that requires intervention or something in between. It s name is sensory processing disorder, and it occurs, advocates say, when the brain cannot properly process incoming signals for an appropriate response.
But families who live with it and the occupational therapists who treat children with the issue say there's no doubt it exists.
To have sensory processing disorder, experts say there must be a significant effect on daily routine. The disorder is usually found in children, though adults can have it, too.
"Everything's coming in and getting messed up for them," said Heidi Tringali, a Charlotte, N.C., occupational therapist who sees a lot of children with sensory issues. "It tastes too strong, smells too strong. They're just disrupted - and their existence is so much more difficult than just a typical developing child."
There have been few published studies on the prevalence of SPD. But one study done in association with the Sensory Processing Disorder Foundation estimates that one in six children is affected by sensory issues, which can range from mild to severe. However, SPD has not yet been officially recognized by the American Psychiatric Association.
It's important to note the differences between a child with sensory processing disorder and a child who's just picky or problematic, experts say. For example, a typical child who steps from an air-conditioned room outside into the heat may whine and complain for a bit. But for a child with sensory problems, it can be almost unbearable.
A typical child who complains that a poke feels like a shove may just be trying to get attention or pick a fight. But to a child with sensory problems, that poke really does feel like a shove.
Kids can be clumsy, but children with sensory problems may struggle in vain to write with a pencil because the motor skills are just so off. Academic and social problems often ensue.
Children's lives aren't segmented, so "if something is going awry, then other things are going to be affected," said Toni Schulken, director of the Charlotte occupational therapy practice Pathways for Learning.
Sensory processing problems occur when the brain's neurons can't correctly interpret incoming signals, said Lucy Jane Miller, executive director of the Sensory Processing Disorder Foundation in Colorado.
When the signals are mixed up, that affects the senses of touch, movement and balance, and space, she said. In the sensory processing world, these are known as the tactile, vestibular and proprioceptive systems.
But there's no cure for sensory processing disorder. Rather, occupational therapists help patients learn to cope.
The SPD Foundation is trying to get the disorder recognized in the "Diagnostic and Statistical Manual of Mental Disorders," the official catalog of mental disorders. The next edition, known as the DSM-5, comes out in 2013.
To put things in perspective, autism wasn't included in the DSM until 1980. Before then, it was seen as a form of childhood schizophrenia. And even when it was recognized, it was limited to just one type and six symptoms until 1987, according to the nonprofit Autism Speaks.
But Eric Taylor, who is in the work group for childhood disorders for the DSM-5, said sensory processing disorder isn't included in the current draft because there isn't yet a clearly defined description or set of symptoms.
For a disorder to be added to the manual, it must fulfill a list of requirements that includes scientific validation and distinction from other disorders, said Taylor, a professor at the Institute of Psychiatry at King's College in London.