CONTACT POINTS 59 Occupational contact dermatitis from ninhydrin in a police officer Contact Dermatitis 2010: 62: 59–60 S. Soost, T. Zuberbier, M. Zuberbier and M. Worm Allergy-Center-Charit´ e, Department of Dermatology and Allergy, Universit¨ atsmedizin Berlin, Berlin, Germany Key words: contact dermatitis; ninhydrin; occupational skin disease. Occupational skin diseases are frequent and have a large socioeconomic bur- den. We have previously shown that educational measures have an impor- tant impact in the care of employees with skin diseases (1). Fig. 1. Patch test reaction to ninhydrin (1:10 in sodium chloride) (1), prepared ninhydrin paper (bank notes) without (2) and sealed into (3) film. In 1910, Siegfried Ruhemann described the chemical reaction of ninhydrin with primary amino groups, which results in the purple dye named ‘Ruhemann’s purple’ (2). Follow- ing its discovery, ninhydrin rapidly became a frequently used reagent for many detection procedures (e.g. immunohistochemical, forensic, or microbiological analysis). Currently, ninhydrin is mainly used to char- acterize amino acids, peptides, and proteins. Furthermore, ninhydrin is used for the forensic purposes in the field of fingerprint examination. Case Report A 48-year-old atopic police officer was referred with eczematous lesions on his hands. Erythematous papules and vesi- cles were present on his fingertips. The detailed occupational history showed that the patient examined