Tattoos and allergies

People often get tattoos to get a reaction from other people, but they might also get one from their skin.

As tattoos are created by injecting chemicals into the skin it is hardly surprising that this can produce an allergic reaction. Indeed, an initial swelling, discomfort and redness to the skin is an expected side effect of getting a tattoo. However, for some people the effect can be longer lasting.

The colour (pigment) of the inks used in the tattooing process is created from metal salts. It is these chemicals that typically cause the allergic reactions. In particular, red dyes tend to cause the most reactions, especially those made from mercury sulphide, also known as cinnabar.

Types of allergic reactions to tattoos

The two most common reactions are allergic contact dermatitis and photoallergic dermatitis. In either case the symptoms will normally be an inflamed red rash, with possibly scaly or flaky skin.

Photoallergic dermatitis refers to the fact that the allergy occurs when the skin is exposed to sunlight. This is more likely with yellow colours, which contain cadmium sulphide. This is also sometimes added to red pigments.

Other reactions can exhibit similar symptoms to some forms of skin cancer, so it is always important to have any rashes or other skin changes examined by your doctor.

Allergic reaction to henna tattoos

Henna tattoos are non-permanent as they are painted onto the skin rather than injected with a needle. The henna dye itself does not normally cause an allergic reaction, however in some cases the dye has another chemical, called para-phenylene diamine (PPD) added to it to make it darker. PPD can cause contact dermatitis, with the skin becoming swollen, red and itchy.

Most professional salons use pure henna so there is no risk, but PPD may be found in henna dyes used by back-street practitioners or in some developing countries.

If you have a history of skin allergies then you should exercise caution before considering a henna (or any other) tattoo.

This article was published on Thu 19 November 2009