Exposures While Picking Berries—In 1939, Bolus15 reported the case of a patient who presented with edema, erythema, and vesicular lesions involving the hands and face after picking berries from a ginkgo tree. Later, patch testing on this patient, using ginkgo fruit, resulted in burning and stinging that necessitated removal of the patch, suggesting an irritant reaction. This was followed by a vesicular reaction that then developed within 24 hours, which was more consistent with allergy. Similarly, in 1988, a case series of contact dermatitis was reported in 3 patients after gathering ginkgo fruit.5
Incidental Exposure While Walking—In 1965, dermatitis broke out in 35 high school students, mainly affecting exposed portions of the leg, after ginkgo fruit fell and its pulp was exposed on a path at their school.4 Subsequently, patch testing was performed on 29 volunteers—some who had been exposed to ginkgo on that path, others without prior exposure. It was established that testing with ginkgo pulp directly caused an irritant reaction in all students, regardless of prior ginkgo exposure, but all prior ginkgo-exposed students in this study reacted positively to an acetone extract of ginkgo pulp and either poison ivy extract or pentadecylcatechol.4
Systemic Contact After Eating Fruit—An illustrative case of dermatitis, stomatitis, and proctitis was reported in a man with history of poison oak contact dermatitis who had eaten fruit from a ginkgo tree, suggesting systemic contact dermatitis. Weeks after resolution of symptoms, he reacted positively to ginkgo fruit and poison ivy extracts on patch testing.16
Ginkgo dermatitis tends to resolve upon removal of the inciting agent and application of a topical steroid.8,17 Although many reported cases involve the fruit, allergic contact dermatitis can result from exposure to any part of the plant. In a reported case, a woman developed airborne contact dermatitis from working with sarcotesta of the ginkgo plant.18 Despite wearing rubber gloves, she broke out 1 week after exposure with erythema on the face and arms and severe facial edema.
Ginkgo leaves also can cause allergic contact dermatitis.19 Precautions should be taken when handling any component of the ginkgo tree.
Oral ginkgo supplementation has been implicated in a variety of other cutaneous reactions—from benign to life-threatening. When the ginkgo allergen concentration is too high within the supplement, as has been noted in some formulations, patients have presented with a diffuse morbilliform eruption within 1 or 2 weeks after taking ginkgo.20 One patient—who was not taking any other medication—experienced an episode of acute generalized exanthematous pustulosis 48 hours after taking ginkgo.21 Ingestion of ginkgo extract also has been associated with Stevens-Johnson syndrome.22-24
Other Adverse Reactions
The adverse effects of ginkgo supplement vary widely. In addition to dermatitis, ginkgo supplement can cause headaches, palpitations, tachycardia, vasculitis, nausea, and other symptoms.14