To the best of our knowledge and following a Medline search (search words: Ginkgo biloba; Epimedium; Horny Goat weed; adverse drug reaction and vasculitis), this is the first reported case of a vasculitic rash induced by either Ginkgo biloba or Horny Goat Weed.
This case highlighted a possible adverse effect of one or more of two herbal remedies. As listed earlier, there are a number of ingredients that make up each of the medicines purchased, and it can not be assumed that the vasculitis was due to either of the active ingredients, as other components may lie at cause.
When using the Naranjo Algorithm2
for estimating the probability of adverse drug reactions, a score of 5 was calculated, equating to the vasculitis being secondary to a reaction from one of the two remedies as being “probable”. However, a number of categories in the algorithm were not applicable in this case.
Herbal remedies are being increasingly used in the western world.3
The percentage of the population that has used complementary and alternative medicine (CAM) at least once is 48% in Australia, 70% in Canada, 42% in USA, 38% in Belgium and 75% in France.4
A recent survey found that approximately 25% of patients hospitalised in internal medicine wards consumed some kind of herbal or dietary supplement.5
With this increasing popularity has come growing interest within the science community. Calapai et al6
have charted the surge in research conducted into phytotherapy within the past decade. However, this increasing interest and usage also brings increasing potential for adverse drug reactions.7–9 Ginkgo biloba
have been widely used in Chinese medicine for centuries.
As herbal remedies go, Ginkgo biloba
has had recent interest by the scientific community with a number of trials conducted into its efficacy in improving memory, treatment in peripheral vascular disease and tinnitus.10–12
Skin manifestations to Ginkgo
include contact dermatitis, diffuse morbilliform eruption and acute generalised exanthematous pustulosis.13
Tomb et al14
reported three cases of contact dermatitis associated with the female ginkgo tree.14
Yuste et al
report the manifestation of Stevens–Johnson syndrome in a 75-year-old gentleman, and they attributed it to the ingestion of Ginkgo
As described previously, the rash in this case does not fit any of these diagnoses.
Other adverse reactions thought to be due to Ginkgo
include: increased risk of bleeding complications, dizziness and gastrointestinal upset.16,17
Horny Goat Weed
The colloquial name for Epimedium
originates from the observation of a Chinese goat herder who noticed that his goats would engage in intense sexual activity after eating a certain herb. Its use as an aphrodisiac in Chinese traditional medicine dates back hundreds of years. The active ingredient is icariin and its mechanism of action is thought to lie in increasing levels of nitric oxide, a smooth muscle relaxant.18
Chiu et al
demonstrated in rabbits how the plant relaxes penile tissue via nitric oxide activity.19
There is also some research into the oestrogenic effects of Epimedium
and its possible usage in postmenopausal women.20
However, extensive scientific research into Epimedium
/icariin is lacking, as is the knowledge regarding its possible side effects.
In summary, we present a case of a 77-year-old gentleman who developed a mild vasculitic rash secondary to ingestion of Ginkgo biloba and Horny Goat Weed. With the increasing trend towards usage of complementary medicines in the West, it is important to keep looking out for and identifying adverse reactions as they materialise.
- This case highlights the importance of always taking a thorough medication history that includes over-the-counter/oral remedies.
- Complementary medicines can also cause potentially serious side effects and when one is found, it should be reported.
- Given the increasing usage of complementary medicines, adverse events towards them will become more apparent and thus a true profile of their safety should be formulated.