Recently, local literature has reported a case of "mad honey poisoning" after consuming honey provided by the patient's friend who bought it from overseas. What is "mad honey poisoning" and what is the advice to the public regarding honey consumption?

"Mad honey poisoning" is caused by ingestion of honey containing grayanotoxins derived from plants belonging to the Ericaceae family, including rhododendrons. Grayanotoxins are neurotoxins that can affect nerves and muscles. Symptoms of poisoning include dizziness, weakness, excessive perspiration, hypersalivation, paresthesia, nausea and vomiting. In severe cases, low blood pressure or shock may occur.

In general, the public is advised to avoid feeding honey to infants less than one year old. This is in line with the advice of the World Health Organization (WHO) as honey can contain Clostridium botulinum spores which can cause botulism.

Members of the public should buy honey from reliable source and apiary. Grayanotoxin-containing honey may cause a burning sensation in the throat, and honey with bitter or astringent taste should be discarded. Whenever possible, information on the types of flowers used to produce the honey should be sought. Travellers to the Black Sea region of Turkey should pay special attention, as there had been cases of grayanotoxin poisoning reported overseas which were attributed to honey from the area.