Systemic Mastocytosis: A Mimicker of Reactive Arthritis.

Our case demonstrated reactive arthritis features (triad of urethritis, conjunctivitis, and arthritis) without an infectious trigger but rather a relapse of mastocytosis. We should think outside the box when faced with such a clinical scenario in the absence of an infectious etiology. Paraneoplastic reactive arthritis is to be considered after excluding an underlying infection.