MIAMI -- Veterans from the first Gulf War with embedded shrapnel have stronger skin reactions to metal allergy than those without shrapnel, according to the first study of cutaneous reactivity to traumatically implanted metals.
Dr. Marianna Shvartsbeyn and her colleagues patch tested 40 Gulf War I veterans to an extensive number of metal allergens and found that, overall, 25% were reactive to zinc and 12.5% to manganese.
The average number of patch test reactions for each group suggested that
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Embedded shrapnel can release metals over time and induce an immunologic reaction in some people.
reactions were stronger among the 18 veterans with shrapnel in their combat wounds (0.72), compared with the 22 who did not have shrapnel fragments (0.63).
Individuals with fragments also tended to react to more substances on the patch testing: The range of positive patch-test reactions was 0-4 for the group with fragments and 0-2 for the group without fragments, she noted.
A total of 56 shrapnel samples were analyzed for the study.
"The pattern of sensitivity fits with the metal components of the shrapnel extracted from the wounds of the soldiers," said Dr. Shvartsbeyn.
All participants were assessed in the spring of 2009 as part of the Depleted Uranium Follow-Up Program at the Baltimore VA Medical Center.
"Depleted uranium did not emerge as a sensitizer," said Dr. Shvartsbeyn, who was an internal medicine resident at the University of Maryland Medical Center, Baltimore, at the time of the study.
A meeting attendee asked about the source of the uranium. "It is in the bullets intended to penetrate armor and it is incorporated in some vehicle shields. Depleted uranium is a very dense metal," said session moderator Bryan Anderson of the Penn State Milton S. Hershey Medical Center, Hershey.
"Some participants had elevated urine uranium if they had retained depleted uranium shrapnel," Dr. Shvartsbeyn said, but none of these participants had significant patch- test reactions.
Embedded shrapnel can release metals over time and induce an immunologic reactivity in some people, the study suggests, said Dr. Shvartsbeyn, currently a resident in the department of pathology at New York University Medical Center, New York.
The veterans were patch tested to 42 reagents using an extended metal series (Dormer Laboratories Inc.), 50 allergens in the North American tray (Dormer), and soluble uranyl nitrate (SPI Supplies and Structure Probe Inc.). Only strong skin reactions of 1+ or above, or crescendo reactions, were considered positive.
Another meeting attendee commented that zinc often is a skin irritant. "We had a high rate of irritant reactions, but we only focused on 1+ reactions in this analysis," Dr. Shvartsbeyn replied.
Because the rates of reactivity to zinc and manganese in the general population are unknown, Dr. Shvartsbeyn and her coworkers also recruited a control group of 46 patients assessed for allergic contact dermatitis at the University of Maryland dermatology clinic from July to December 2009. This group demonstrated lower reactivity rates to zinc (8.6%) and to manganese (6.5%).
"A threefold reactivity in zinc and twofold reactivity to manganese [among the veterans] makes us think these could be the true sensitizers," she said.