Allergic contact urticaria caused by a chameleon in a patient sensitized to Ficus benjamina

Abstract

Rationale Reptiles are an uncommon cause of allergy. Methods A 31-year old man presented with a long-lasting history of rhino-conjunctivitis and sneezing from March to May. The patient, who kept a chameleon ( Chamaeleo calyptratus) as a pet since one year, also suffered from recurrent erythema, itch, and urticarial lesions after skin contact with the animal. Reactions started within few minutes and were restricted to the contact sites with the animal's claws. No comparable reactions occurred in other subjects when getting in touch with the reptile. Results Allergy testing confirmed allergy to tree pollens (birch, ash) and additionally revealed sensitization to house dust mite, cat, and ornamental Ficus benjamina. Apparently the contact dermatitis in the patient was due to passive transfer of Ficus benjamina allergens to the patient's skin by the chameleon which used climbing on a big Ficus benjamina tree in the patient's home thereby contaminating its claws with the plant's allergenic milky sap. Careful examination revealed clear perforation of many of the plant's leaves by the pointed claws. The patient denied respiratory symptoms from Ficus benjamina and adverse reactions to Ficus-associated fruits. Conclusions We report a strange case of Ficus benjamina allergy simulating allergy to a reptile.