Contact sensitization to Geranium robertianum L. in an amateur gardener.

A 68-year-old male retired non-atopic school librarian was referred for suspected plant contact dermatitis. The patient had taken up gardening as a hobby when he retired from work: mowing the lawn, cutting hedges and weeding in his garden. For 6–10 years, he had suffered from transient dermatitis on his eyelids, which he attributed to a habit of wiping his eyelids with his hands during gardening. The patient suspected weeds, and especially Herb Robert, which had spread in his garden, to be the main culprits. He tried to avoid contact with this plant by using safety glasses and gloves while gardening. Prior to referral, patch testing was performed with the baseline series and Herb Robert leaf, flower, and stem (tested ‘as is’), and the only reaction was slight erythema at D3 caused by the plant leaf. Prick tests elicited positive reactions to dog, cat, and house dust mite. Patch testing was repeated with the baseline series (TRUE Test® Panel 1–3 supplemented with pet.-based allergens) and eye drops, various Compositae (Asteraceae) plant extracts and allergens, primin and lichen acid mix, falcarinol, and the patient’s own plant Herb Robert. The plant was chopped and tested ‘as is’ with