DESTIN, FLA. — Classic polyarteritis nodosa, or PAN, is curable in the majority of cases, Dr. John H. Stone said at the annual Rheumatology on the Beach.
The belief that this form of vasculitis is incurable is one of many myths about systemic vasculitides, he said, noting “classic PAN” means disease that does not include palpable purpura, glomerulonephritis, lung disease, or antineutrophil cytoplasmic antibody-positive disease.
In a study reported last year at the annual meeting of the American College of Rheumatology, two-thirds of PANpatients were cured, though that figure is likely high because patients other than those with classic PAN were included, noted Dr. Stone, a Boston-based rheumatologist and editor of Rheumatology UpToDate.
In his experience with classic PAN in the past 5 years, 17 of 21 patients were cured. Some were treated with steroids, and some were treated with steroids and cyclophosphamide; all were tapered completely off their drugs. The remaining four patients remained on low-dose steroids to control persistent skin disease, he said.
“As we understand PAN better, we are going to recognize that we can subclassify it phenotypically a bit more precisely,” he said. Forms of the disease are tied to hepatitis B, there is the classic curable type, and there may be other subtypes.
To debunk another myth about systemic vasculitis, Dr. Stone described a patient with Wegener's granulomatosis who was diagnosed with rheumatoid arthritis based on the presence of arthritis and nodules on his elbows. Arthritis plus nodules does not necessarily equal RA, he said. The Churg-Strauss-type granulomas seen in this patient can be associated with Churg-Strauss syndrome, but another myth is that Churg-Strauss syndrome is the most common cause of the nodules. In fact, Wegener's granulomatosis is the most common cause, Dr. Stone explained.
Myths also exist about treatment for vasculitis. Chemotherapy with cyclophosphamide is indicated in patients with mononeuritis multiplex, central nervous system disease, rapidly progressing glomerulonephritis, mesenteric vasculitis, cardiac involvement, or alveolar hemorrhage. Nonhealing cutaneous ulcers or excessive steroid toxicity are also indications.
Data from one study, presented only in abstract form, show that intravenous cyclophosphamide treatment once every 2 weeks is as effective as oral daily cyclophosphamide but safer. However, daily oral treatment is currently the preferred approach for induction of remission. Some studies suggest oral therapy improves the chance of sustained remission. Oral cyclophosphamide can be titrated based on white cell count, another safety feature.
Patients who fail to respond to conventional daily cyclophosphamide should be considered to have an infection. Systemic vasculitis is almost always reliably controlled with conventional therapy, thus it is important to consider aspergillosis and other agents in refractory cases. Induction of neutropenia is not essential for achieving remission. The goal is to maintain white cell count above 3,500 or 4,000/mm
Episcleritis often is an overlooked clue that a patient's vasculitis has flared. Courtesy Dr. John H. Stone
Episcleritis Is Sign Of Vasculitis Flare
A frequent signal of disease flare in patients with systemic vasculitis is episcleritis, Dr. Stone said.
The Wegener's granulomatosis patient who was misdiagnosed with RA presented with this ocular condition—the most common ocular manifestation of systemic vasculitis—signaling renewed disease activity. The patient was having a flare but didn't realize it.
The onset of episcleritis is often overlooked. Recognizing it provides a very important clinical clue to renewed disease activity in many medium-to small-vessel vasculitides, including PAN, Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, and rheumatoid vasculitis. The condition can also occur in the large-vessel vaculitis, Cogan's syndrome, which is characterized by a number of ocular manifestations, he noted.
Episcleritis may be striking, with bilateral redness of the eyes as was the case in this patient, or it can be more subtle and fleeting. But nonetheless, it is a harbinger of disease flare, Dr. Stone said.