Exploring a rare case of occupational senna allergy.

BACKGROUND: Cassia angustifolia, or senna, is a plant belonging to the Fabaceae family, widely used as a laxative and as a colouring agent in hair dyes. Senna is rarely reported as an occupational allergic sensitizer in the current literature. AIMS: To describe the case and diagnostic approach of a suspected occupational senna allergy. CASE REPORT: A male phytopharmaceutical warehouse worker reported bronchial, conjunctival and nasal symptoms immediately upon exposure to senna. We were able to document in vitro sensitization, finding IgE-binding proteins in senna, and in vivo sensitization through positive skin tests and conjunctival provocation test. CONCLUSION: Our study confirms that senna may cause occupational rhinoconjunctivitis symptoms with an IgE-dependent mechanism and is the first to confirm it through specific conjunctival provocation test.