There are similar cases of poisoning occurring much more recently,
related to consumption either of fresh honey containing rhododendron
pollen or of rhododendron nectar. Most recent accounts relate to Turkish
cases, but descriptions of the illness in Switzerland have also been
published. We reported the following in our house journal, the SCIEH
Weekly Report, in 1996 [1].
A case has been reported [2] of a previously well 49 year old Turkish
male who developed acute vertigo and a sensation of chest compression
within one hour of eating bread and fresh wild Turkish honey. On
examination, the patient was in poor condition and had a slow pulse and
low blood pressure (sinus bradycardia of 27 beats per minute and
hypotension of 90/45 mmHg). The patient recovered within 24 hours with
symptomatic treatment and administration of atropine. The history of
eating wild honey and the cardiovascular signs indicated grayanotoxin
poisoning. Pollen of Rhododendron ponticum (the species common in the UK)
was found in a sample of the honey. Similar cases were reported in
visitors to eastern Nepal who ate local honey derived from other
rhododendron species (probably R.arboreum or R.campanulatum).
The diterpenoid grayanotoxins and their analogues are known to occur
in honey derived from the nectar of some species of rhododendron and can
produce gastrointestinal symptoms and life-threatening cardiovascular
effects. Rhododendron honey is said to be toxic only if very recently
produced by the bees, so commercially produced honey is unlikely to
produce any effects. In addition, honey produced in the spring during the
rhododendron flowering season is mostly consumed by the bees and is rarely
harvested.
A Scottish case has been reported where a man licked rhododendron
nectar from his hands and rapidly experienced paraesthesiae, loss of
coordination and an inability to stand, symptoms which resolved completely
a few hours later [3].
References
1 Anon. Bradycardia due to wild honey. SCIEH Weekly Report 1996; 30:
275
2 Newsletter of the WHO Surveillance Programme for Control of
Foodborne Infections & Intoxications in Europe 1996; 49/50: 6
3 Cooper MR, Johnson AW. Poisonous plants & fungi: an illustrated
guide. HMSO, 1991
Competing interests:
No competing interests
04 August 2000
Peter Christie
Consultant Epidemiologist
Scottish Centre for Infection & Environmental Health
Rapid Response:
Honey poisoning: beware the rhododendron
There are similar cases of poisoning occurring much more recently,
related to consumption either of fresh honey containing rhododendron
pollen or of rhododendron nectar. Most recent accounts relate to Turkish
cases, but descriptions of the illness in Switzerland have also been
published. We reported the following in our house journal, the SCIEH
Weekly Report, in 1996 [1].
A case has been reported [2] of a previously well 49 year old Turkish
male who developed acute vertigo and a sensation of chest compression
within one hour of eating bread and fresh wild Turkish honey. On
examination, the patient was in poor condition and had a slow pulse and
low blood pressure (sinus bradycardia of 27 beats per minute and
hypotension of 90/45 mmHg). The patient recovered within 24 hours with
symptomatic treatment and administration of atropine. The history of
eating wild honey and the cardiovascular signs indicated grayanotoxin
poisoning. Pollen of Rhododendron ponticum (the species common in the UK)
was found in a sample of the honey. Similar cases were reported in
visitors to eastern Nepal who ate local honey derived from other
rhododendron species (probably R.arboreum or R.campanulatum).
The diterpenoid grayanotoxins and their analogues are known to occur
in honey derived from the nectar of some species of rhododendron and can
produce gastrointestinal symptoms and life-threatening cardiovascular
effects. Rhododendron honey is said to be toxic only if very recently
produced by the bees, so commercially produced honey is unlikely to
produce any effects. In addition, honey produced in the spring during the
rhododendron flowering season is mostly consumed by the bees and is rarely
harvested.
A Scottish case has been reported where a man licked rhododendron
nectar from his hands and rapidly experienced paraesthesiae, loss of
coordination and an inability to stand, symptoms which resolved completely
a few hours later [3].
References
1 Anon. Bradycardia due to wild honey. SCIEH Weekly Report 1996; 30:
275
2 Newsletter of the WHO Surveillance Programme for Control of
Foodborne Infections & Intoxications in Europe 1996; 49/50: 6
3 Cooper MR, Johnson AW. Poisonous plants & fungi: an illustrated
guide. HMSO, 1991
Competing interests: No competing interests