Most people associate allergies with the standard hay fever-like symptoms: runny nose, itchy eyes, and sneezing. But allergies have a broad reach and can even contribute to neurological problems such as tics and Tourette's syndrome.

Tics are involuntary movements and vocalizations of sounds and words which are not appropriate. Patients with frequent, severe tics are often diagnosed with a neurological dysfunction known as Tourette's syndrome.

There are few definitive answers for why tics and allergies are linked, but physicians such as Allergist Dr. Stuart Agren see evidence of the correlation on a regular basis.

Dr. Agren is the director of the Family Allergy Clinic in Mesa, Arizona. For the past several years, he has been treating patients with tics using allergy immunotherapy. With immunotherapy, patients take extracts of the dusts, molds and pollens that they are allergic to in gradually increasing amounts. They can take the extracts as oral drops under the tongue. The majority of Dr. Agren's patients have either seen their tics decrease or disappear within a few months of starting immunotherapy.

Samantha Malaki was one such patient. When she was just 8 years old, she developed a motor tic that caused her neck to jerk violently every few seconds.

"It was very scary," said Samantha's father, Sao Malaki. "I would look back in the car when I was driving, and it was like somebody was hitting her in the neck."

The tic caused Samantha extreme pain in her neck and back. She began having trouble sleeping at night and concentrating on her homework. At school, her peers teased her.

Samantha underwent MRIs and CAT scans, but doctors remained baffled about the source of the tics. She tried seven different medications, but they didn't help and had troubling side effects.

Within two months of starting allergy shots immunotherapy at the Family Allergy Clinic, though, her tic was gone. It has been over three years now, and she remains free of the tic.

Allergies have been linked to a wide variety of health problems including headaches, eczema, and hyperactivity. It is estimated that allergies affect at least one in five Americans.