A Rare Genetic Mutation Leading to a Deficiency of Adenosine Deaminase 2 Enzyme in a Long-Standing Case of Cutaneous Polyarteritis Nodosa: A Case Report.

Vasculitis is an inflammatory disorder of blood vessels affecting multiple organs. A deficiency of adenosine deaminase enzyme type 2 (DADA2) is a novel condition identified as a monogenic cause of cutaneous vasculitis. Since its first description in 2014, numerous case series and literature across several countries have expanded the scope of our understanding of this rare genetic condition. However, due to a scarcity of reported cases in adults, little is known regarding its full spectrum of clinical presentations, treatment guidelines, or outcomes in the adult patient population. It is established that it commonly affects multiple organ systems, such as the skin, musculoskeletal, neurological, hematological, gastrointestinal, and renal systems. It presents with a wide range of clinical manifestations, including fever, Livedoid rash, cutaneous polyarteritis nodosa, polyneuropathy, and immunodeficiency. Such a varied clinical spectrum opens an opportunity for discussion to list some of the differential signs of DADA2. In this article, we report a unique case of a 26-year-old male with a delay of nine years in diagnosing a genetic mutation that led to DADA2. In addition, a 10-year history of recurring cutaneous ulcers and peripheral neuropathy makes this case a noteworthy addition to the literature on cutaneous vasculitis and its miscellaneous causes.