LOS ANGELES — More than two decades since the first U.S. invasion of Iraq, medical authorities can’t agree on a definition of Gulf War illness, the mysterious array of ailments afflicting many veterans of the conflict.
In the latest attempt to settle the debate, the Department of Veterans Affairs commissioned the prestigious Institute of Medicine to develop a definition. But in a report released Wednesday, its experts said the symptoms — including joint pain, fatigue, headaches, rashes, digestive problems and cognitive impairment — vary so widely that there was no way to reach a scientific consensus.
So they chose two definitions.
The first, developed by the U.S. Centers for Disease Control and Prevention, takes a broad view of the illness. It may be most useful to doctors who don’t want to overlook any patients who may be afflicted.
A second, more restrictive definition was formulated by scientists studying Kansas veterans and may be better suited to research studies.
Defining the illness — and the universe of people who have it — is essential for investigating potential causes and standardizing treatments.
When veterans first began reporting a strange variety of opaque symptoms in the wake of the 1991 war, they were often met with skepticism. Many studies, however, have shown that service members deployed to the war went on to suffer a variety of health problems at a higher rate than those deployed elsewhere.
Up to one-third of the 700,000 U.S. troops who served in Operation Desert Shield and Operation Desert Storm are thought to be affected.
But without a blood test or other biomarker to distinguish Gulf War illness, it can only be diagnosed by its symptoms, many of which occur in other conditions such as chronic fatigue syndrome and fibromyalgia.
Severity ranges from mild to debilitating. In some cases, veterans became ill immediately after the war. Others got sick years later. Recovery varies too.
The biggest mystery is the cause. Exposure to pesticides, nerve agents and smoke from burning oil wells have all been investigated as possible culprits, without definitive results.
At the behest of the VA, the experts did resolve one debate.
When it first appeared, the illness was called Gulf War syndrome. Then other terms began appearing in the medical literature, including “unexplained illness” and “chronic multisymptom illness,” which became widely accepted.
Gulf War illness is the most appropriate name, the Institute of Medicine concluded in its report.