Autistic children are not the only ones who chew on their clothing, but this behavior does occur commonly in kids with sensory processing disorders. Shirt biting can leave clothes in disarray and your budget in tatters, too, so it's worth trying to reduce the chewing. You can accomplish this by substituting other objects or redirecting your child when he starts gnawing on his shirt.
Autistic children, and non-autistic children, chew on objects such as clothing for several reasons. Chewing can be soothing, calming a child down when he's under tension. Some children use chewing when they need to focus on an activity. It can also serve as a handy, always present form of oral satisfaction for children with an oral fixation, a common occurrence in autistic children. If your child won't eat anything but pureed or soft foods, chewing his clothes helps him satisfy his chewing urge. For non-verbal children, excessive chewing that develops suddenly might be a sign that their mouth hurts because they have teeth coming in or they have a cavity, the National Autism Resources site cautions.
When a child develops any type of unhealthful habit, your reaction to it can make it better or worse. If you yell, get angry, react physically by pulling the shirt away from his mouth, you could make the behavior worse. If your child responds to oral communication, couch corrections in positive rather than negative terms, child developmental psychologist Rene Hackney suggests. Rather than saying "don't" or "no," simply say, "Clothes go on your body" or "Shirts are for wearing." Negative reactions can reinforce negative behaviors.
Chewing can occur when children who don't move around much or who spend most of their time inside have pent-up energy that needs release. When your child starts chewing on his shirt, take his behavior as a sign that he might need to go out and let off some steam by running around.
You can buy substitute chewing objects that save your child's clothing and satisfy his need to chew at the same time. Chew necklaces or bracelets, rubber tubes that fit over pencils or other objects, washcloth strips or hard foods such as carrots can save your child's clothing and your clothes budget and nerves. If the behavior persists, working with an occupational therapist who has experience dealing with children with oral fixations can help, the Early Intervention Support website recommends.