An adult male diver developed limb pains and peripheral neurologic sig
ns following a series of dives. He was treated for acute neurologic de
compression illness (DCI) and responded well, but subsequently he dete
riorated and developed features of a progressive multisystem disease.
Investigation confirmed a clinical diagnosis of polyarteritis nodosa c
omplicated by a mononeuritis multiplex. Vasculitis is uncommon and its
masquerade as neurologic DCI may be unique. However, this case emphas
izes the importance of careful clinical assessment and illustrates the
potentially wide differential diagnosis of DCI.