You might know that cobalt, or cobalt chloride, is a metal. What you might not know is that cobalt is relatively commonplace. Manufacturers combine it with other metals to make metals stronger. Cobalt is also used by the cosmetic industry to create blue makeups. Unfortunately, cobalt is also a common contact allergen, which can cause an allergic contact dermatitis. Allergic contact dermatitis is an allergic reaction where you can get a rash days after coming into contact with an allergen. This type of allergy is something that can develop over time, especially if you have high exposure to the contact allergen. Symptoms include a rash that can occur days after exposure. In addition, metal allergies tend to go together. If you have a nickel allergy, you might also have a cobalt allergy.
Here are some classic stories of someone who might have a cobalt allergy:
Ann owns her own boutique makeup stores downtown. She enjoys trying new lines of eye makeup and particularly likes blue colors. However, over the past week, she’s been experiencing lots of redness and itching, especially on her eyelids. She has never had this happen before but has noticed that her rash did get better when she stopped using eye makeup.
Mark works in a metal factory. He has been having red, itchy patches on his hands recently. Even though his day to day work is tough on his hands, he has never had symptoms like this before. He describes that his rash is almost like the time he touched poison ivy, although he is sure he hasn’t recently.
In these cases, we would be suspicious of Ann’s blue makeup and Mark’s job as a metalworker as a potential cause for their rashes. Real cases are usually much more complicated than these simplified stories, but they don’t have to be. If these stories sound similar to yours, it might be worth investigating if you have allergic contact dermatitis to cobalt.
What is cobalt found in?
Common sources of cobalt are cosmetics, metals, and wet clay. Cosmetic companies use it to produce blue colors and include it in products like eye makeup and blue tattoo pigments. The metal industry uses it in the manufacturing of hard metals. As a result, if you are working with steel everyday or have surgical stainless steel implants, you are likely coming into contact with cobalt. Less obvious sources are wet clay and plastics.
So what occupations are most at risk of developing cobalt allergies? You guessed it! Those working with these type of materials everyday (e.g. metal workers, bricklayers, and pottery workers). This makes sense because a cobalt allergy develops over time after repeated exposure.
Where will you be itching?
As with any contact allergen, itching and rashes occur at the site of contact. We’ve mentioned above, makeup and steel are common products that contain cobalt. As a result, people will get itching, redness, and scaling on their face (and specifically eyelids) or on their wrists, neckline, and ears if they wear jewelry. People that work with metals or pottery will tend to get symptoms on their hands like Mark. In more severe cases, these lesions can even progress to blistering. In rare cases the rash can occur systemically. This usually occurs if you have both a nickel and cobalt allergy.
What is the treatment?
Avoidance is the best policy. Here are some strategies you can use to avoid cobalt:
- Avoid wearing jewelry that is not 18k gold, sterling silver, or platinum. As mentioned above, many metals contain at least some cobalt which can spark a reaction. Choose only pure metal jewelry to avoid those mixed with cobalt.
- Cover metal handles and keys. Door handles and keys are two sources of metal that people don’t often think about. Covering your handle with duct tape and using plastic or rubber key guards can help you avoid coming in contact with cobalt. Alternatively, you can paint your door handles with clear nail polish to create a protective layer between you and metal
- Use plastic zippers or fasteners. Buttons and zippers are other sources of metal which you want to avoid.
As always, reading labels is a good way to make sure the product you are using does not contain cobalt. We know that checking the label on everything can be tough. Check out our safe list for products that avoid the common contact allergens across many categories.
Cobalt is also found in food and there is some evidence that a low cobalt diet might help. If you’ve been patch tested and found to be allergic to cobalt, follow your safe list of products. However, if you’re still getting rashes then a food source may be problem. Foods that are high in cobalt that you should avoid include chocolate, nuts, beans, and liver. Cobalt also used to be put in beer as a foam stabilizer. However, more recent food safety guidelines have decreased the use of cobalt in beer.
Do you have a severe rash now? There are some things you can do in the meantime until you figure out the cause. Barrier creams are thick oily greasy moisturizers. Applying barrier creams, like Vaniply, can help prevent the allergen from reaching your skin. Meanwhile, topical steroids can be used to reduce the severity of your rashes.
How is a cobalt allergy diagnosed?
If you think cobalt is causing your rash, you can try avoiding the products we have listed above and see if the rash goes away. For example, in our cases above Ann could try not using blue makeup. If the rash comes back when you reuse the substance, then you may have found your culprit.
If you are unsure whether or not you have a cobalt allergy (contact allergens can be tricky! See our main article for the many other contact allergens), you can talk to your dermatologist about patch testing. Patch testing is used to help doctors determine whether you have a true skin allergy (allergic contact dermatitis) or an irritant contact dermatitis (click here for the difference). This is determined by putting together your history, your job, your exposure, the environment, and your patch testing results.
Think a different contact allergen may be the culprit?
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