Contact allergy and depigmentation from alstroemeria.

Alstroemeria plants have increased in popularity in recent years, but surprisingly few cases of contact allergy have been reported. Observations of combined sensitivity between Alstroemeria and Tulipa have given support to the assumption that they contain identical sensitizing agents. A patient working as a gardner developed a dermatitis from Alstroemeria. Patch tests with Alstroemeria were positive, but patch tests with Tulipa were negative. 2 months after test application, the patient showed depigmented areas at the test sites and at the sites of a previous dermatitis. The depigmented test areas remained unchanged at least a year after test application. Whether the depigmentation was due to some unique character of the molecular structure of the unknown Alstroemeria allergen, or to a unique biological characteristic of the patient, remains to be determined.