A shopkeeper reaches for a packet of Marlboro cigarettes in London
A shopkeeper reaches for a packet of Marlboro cigarettes in London in this file photo taken November 28, 2013. Cigarette maker Philip Morris International Inc cut its earnings forecast for 2014 and said it is proving to be a "complex and truly atypical" year for the company. Reuters

Health officials from Birmingham have warned parents about the dangers of their children, especially toddlers, being accidentally exposed to electronic (E) cigarette refills. The refills, the experts warned, contain concentrated nicotine, a few drops of which could pose serious threat to a child less than five years of age.

In a letter published in the Archives of Disease in Childhood, doctors from Good Hope Hospital in Birmingham called for greater safety of young kids who are more vulnerable and likely to come in contact with e-cigarette liquid refills. They said that the liquid can lead to "severe symptoms" among toddlers.

The warning comes after a woman from U.K. rushed her 30-month-old-child to Good Hope Hospital in Birmingham after the kid was spotted placing a refill cartridge in her mouth. Though the mother immediately snatched the cartridge away from the child, she was unsure of how much nicotine was already consumed, and so took her to the hospital as a precautionary measure.

The child was kept under observation for many hours in the hospital, during which she vomited once. The two-year-old child was soon discharged since no further symptoms were observed.

However, the doctors are of the opinion that more such cases might be witnessed in the years to come since e-cigarettes are becoming very popular, especially in the U.K. and U.S. "The exploratory nature of young children and the attractive packaging of refills is a dangerous combination likely to lead to a growing incidence of accidental exposure to concentrated nicotine solution. The risk posed by nicotine liquid to children needs to be recognised, acknowledged and acted upon by all," the doctors wrote in the journal, according to Daily Mail.

Between Sept. 2010 and Feb. 2014, 215 cases of accidental swallowing of liquid nicotine existing in e-cigarettes were reported. As per Onmedica, the figures released by the U.S. Centers for Disease Control and Prevention (CDC) earlier this year, showed a marked increase in calls to the poison centres related to swallowing of nicotine liquid.

More than half of the calls were from parents of children below five years of age. An adult consuming doses as low as 40 mg might be in a risk of nicotine poisoning. In the case of children, the risk is much higher. Severe nicotine poisoning can lead to convulsions, irregular heartbeat, coma and even cardiac arrest.