Treatment for Polyarteritis Nodosa (PAN)

Disease Classification and Initial Assessment

Disease severity should be assessed to guide treatment decisions, with severe disease defined by life- or organ-threatening manifestations such as renal insufficiency and tissue ischemia 1

For newly diagnosed active, severe PAN, initiate treatment with cyclophosphamide and high-dose glucocorticoids rather than glucocorticoids alone 2
Consider intravenous pulse glucocorticoids over high-dose oral glucocorticoids for initial treatment of severe disease 3
Cyclophosphamide therapy should generally be limited to 3-6 months per course due to toxicity concerns 4
After achieving remission with cyclophosphamide, transition to another less toxic immunosuppressive agent such as methotrexate or azathioprine for maintenance therapy 4
For patients unable to tolerate cyclophosphamide, use alternative immunosuppressive agents with glucocorticoids rather than glucocorticoid monotherapy 5

For newly diagnosed active, non-severe PAN, use non-glucocorticoid immunosuppressive agents (typically azathioprine or methotrexate) plus glucocorticoids rather than glucocorticoids alone 2
This approach may help minimize glucocorticoid use and subsequent toxicity 2

For patients in remission receiving non-glucocorticoid immunosuppressive therapy, discontinue these agents after 18 months rather than continuing indefinitely, provided sustained remission has been achieved 6
The optimal duration of glucocorticoid therapy is not well established and should be guided by the patient's clinical condition, values, and preferences 4

For severe PAN refractory to initial treatment with glucocorticoids and non-cyclophosphamide immunosuppressive agents, switch to cyclophosphamide rather than increasing glucocorticoids alone 4
Plasmapheresis is not routinely recommended in combination with cyclophosphamide and glucocorticoids for non-HBV-associated PAN 2

For patients with PAN with nerve and/or muscle involvement, physical therapy is recommended 4
For patients with clinical manifestations of deficiency of adenosine deaminase 2 (DADA2), tumor necrosis factor inhibitors are strongly recommended over glucocorticoids alone 4
For patients with abdominal involvement who become clinically asymptomatic, follow-up abdominal vascular imaging is recommended to assess disease control and treatment response 3

Untreated PAN carries a poor prognosis, with severe PAN having a mortality rate of 40% at 5 years 7
Serial neurologic examinations are preferred over repeated electromyography/nerve conduction studies for monitoring disease activity in patients with peripheral motor neuropathy 3

Avoid indefinite routine vascular imaging if abdominal vascular disease is shown to be quiescent 3
Consider DADA2 in patients with PAN-like syndrome with strokes, as these patients respond better to TNF inhibitors than conventional therapy 4