HOUSTON — Strict adherence to diagnostic criteria for Behçet's disease can lead physicians to misdiagnose patients who actually have complex aphthosis, Peter J. Lynch, M.D., warned at a conference on vulvovaginal diseases sponsored by Baylor College of Medicine.
Oral and genital ulcers characterize both conditions, but classic Behçet's disease typically leads to blindness and death, said Dr. Lynch, a professor emeritus at the University of California, Davis.
Though recurring and troublesome, complex aphthosis is a far more benign disorder.
“In the United States and Western Europe, complex aphthosis is usually not associated with systemic symptoms and signs. That's important, because I don't want these women labeled with Behçet's disease that they don't really have,” Dr. Lynch said.
“If they tell their primary care doctors that they have Behçet's disease or if they go online and look up Behçet's disease,” he warned, “they're going to be overwhelmed with the fact that they are going to be dead in a couple of years, and they are going to have terrible brain disease, and they are going to go blind. This is very frightening.”
Dr. Lynch traced the overlap to diagnostic criteria developed in 1990 by the International Study Group for Behçet's Disease (Lancet 1990;335:1078-80). Although other criteria have since been written to avert confusion, he said, the original ISGBD guidelines are still widely used.
If patients with complex aphthosis are to be included in the Behçet's disease spectrum, Dr. Lynch suggested the “Western” form of the disease be distinguished from the “Eastern” form, which he characterized as classic Behçet's disease.
He contrasted the two forms as follows:
▸ The Eastern form occurs along the “Silk Road” from Asia to Eastern Europe; the Western form presents in Western Europe and North America.
▸ Men outnumber women among patients with the Eastern form; women are more likely to be affected in the West.
▸ Central nervous system involvement occurs only in the Eastern form.
▸ Posterior eye inflammation often leads to blindness with the Eastern form of the condition. Anterior eye disease sometimes occurs with the Western form, but is less severe and rarely, if ever, leads to vision loss.
▸ The HLA-B51 haplotype is almost always positive with the Eastern form. People with this haplotype are much more likely to develop Behçet's disease if they live along the Silk Road (relative risk about 6.0) than in Western countries (relative risk about 1.5).
▸ Prognosis is poor in the East, good in the West.
Complex aphthosis has a nonspecific histology and is usually diagnosed by ruling out other conditions, according to Dr. Lynch. These ulcers can appear simultaneously in oral and genital locations, but are often independent of each other. “Almost always you will get a history of oral ulcers in the past, but they don't come out exactly at the same time,” he said.
Comparing aphthosis major ulcers to ordinary canker sores, Dr. Lynch said the former are larger, longer lasting, and more painful. The aphthosis ulcers also heal with some scarring and are more likely to appear on mucosa in women and on skin in men.
“There are no good age data, but in my own practice over the years I am impressed with number of very young women from age 13 to about 20 who develop this,” he said.
Dr. Lynch said most lesions respond within a few days to topical application of high potency steroids such as fluocinonide and clobetasol. He also recommended lidocaine or sucralfate for pain relief, and suggested 5 mg/cc of triamcinolone acetonide for larger ulcers and ulcers that do not respond to topical steroids.
For systemic therapy, Dr. Lynch proposed 7-10 days of treatment with systemic steroids. Dapsone, colchicine, pentoxifylline, and thalidomide can be effective for episodic treatment and prophylaxis, he said, warning against the use of thalidomide and other tumor necrosis factors in women who are of child-bearing age.