There are anecdotal reports of nickel in sweat causing contact dermatitis, but I wanted to look into the science of this phenomenon to see if it had any scientific backing. Google is my friend. Here’s what I found:
The first study I came across examined the incidence of nickel in bodily fluids after people were fed nickel. They found that nickel concentration increased in blood and urine, but did not decisively change in concentration in sweat.
This study was excellent for explaining the sources of nickel in our environment, high-nickel foods, other metal allergy incidences related to nickel, testing methods, and barrier options to prevent reactions. Nickel in foods is a common source of nickel allergic reactions, even skin reactions and GI issues, and most nickel-allergic individuals tend to move toward a low-nickel diet.
I then found evidence that sweat corrodes nickel items enough to cause nickel to be present on the skin and cause allergic contact dermatitis. Getting warmer, but still not nickel actually in the sweat coming from the body. The articles did mention that nickel is not so easily released from stainless steel objects because it is more tightly bound, but that it can frequently get through platings on metal objects.
Finally I came across my answer. Here and here are two studies supporting nickel being present in sweat, one of which decisively measured the levels of metals, including nickel, in sweat.
Proven by science, nickel can indeed be excreted in sweat, along with other metals like lead. This means that people with nickel allergies have every reason to be wary of sweating excessively, and to need to wash regularly to prevent nickel buildup on their skin. Sweating can indeed cause allergic contact dermatitis in nickel-allergic people. I hope that this research, while far from being groundbreaking, might help people who need to document aspects of their nickel allergy with firm evidence.
Do you have a nickel allergy? What precautions do you take? Comment below.