May 28 (HealthDay News) -- Stimulant chewing gum can be dangerous if used excessively by children and teens, warn doctors who wrote a case report about a teenage boy who was hospitalized after chewing a large amount of the caffeine-containing gum.

The case involved a 13-year-old Italian boy who was taken to hospital after his family noted he was agitated and aggressive, which wasn't typical for him. The boy also had abdominal discomfort, increased and painful urination, and prickling sensations in his legs.

Emergency department doctors found that the boy had a rapid heartbeat (147 beats per minute), rapid breathing (25 breaths per minute) and elevated blood pressure (145/90 mm Hg). His blood tests were normal and he tested negative for illicit drugs.

The boy spent the night in hospital without treatment and was discharged the following morning, with the only unusual symptom being a slow heartbeat (40 bpm). The doctors later learned that the boy had consumed two packets of stimulant chewing gum within a four-hour period. The two packs of gum contained a total of 320 milligrams of caffeine, slightly more than three regular cups of coffee.

The boy met the criteria for diagnosis of caffeine intoxication, said the doctors.

"Our patient…presumably had high caffeine sensitivity in view of his low habitual caffeine intake, so 320 mg was a substantial amount of caffeine," wrote Francesco Natale, of the Second University of Naples and Monaldi Hospital in Naples, and colleagues.

"It was unlikely that…other ingredients of the chewing gum played a part in this case, because their doses were low or they would induce different signs and symptoms from those found in our patient. The use of stimulant chewing gum should be considered in cases of caffeine intoxication. The risk of intoxication is high in children and teenagers in view of general caffeine-naivety, and the unrestricted sale of these substances," the authors concluded.

The case study appears in the May 30 issue of The Lancet.

SOURCE: The Lancet, news release, May 28, 2009