The Daily Apple: Apple #680: Henna Tattoos

This weekend at the state fair, I got a henna tattoo.

I went for a simple $8 design of a sun. The tattoo artist offered to extend it so it goes up my finger. I said OK by me.
(Photo by the Apple Lady)

Naturally, I asked the woman who gave me the tattoo all sorts of questions about it. And again naturally, I have still more questions. So here follows some of the things she told me mixed in with some of the things I looked up and have learned since.

What Is Henna?

Henna is a dye made from the ground-up leaves of the henna plant (Lawsonia inermis).

It's sometimes also referred to as mehndi or mehandi or mendhi.

The henna plant is a pretty non-descript looking shrub.
(Photo from Sailu's Kitchen)

The plant is a flowering shrub that grows in all sorts of places, including the US and Australia, but it's most prevalent in the dry, arid regions in northern Africa, India, and the Middle East, and it also grows in Southeast Asia.

The leaves themselves won't stain anything; you have to crush them or grind them up before they will work as a dye. Most people make their henna dye from powdered henna.

Henna has been used as a dye for both hair and skin for centuries in several different cultures & religions in the areas where it grows.

Though people of Muslim, Hindi, Jewish, and other faiths have all used henna, they all generally consider that henna tattoos mean some sort of good luck or blessing.

Traditional bridal mehndi -- henna tattoo on the hands & wrists prior to a marriage, here, on a bride from India.
(Photo from Sameera Threading)

Why it's Usually Brown, and Why on the Hands & Feet

Traditionally in most of these cultures, women's hands or feet, or both, were tattooed before a wedding as a way to invoke good luck for the bride or the marriage. But now lots of people get henna tattoos for lots of purposes.

It takes a while for the henna stain to sink into the skin. So you don't know right away how dark the tattoo will be. The stain can range from tan to light brown to auburn to dark brown.

What color the tattoo becomes depends on the person's skin, where on the body the tattoo is applied (some areas take up the stain better than others), how much henna is present in the stain mixture, whether the henna artist has used some form of mild acid like lemon juice or vinegar as an adjuvant, etc.

Because the color of the stain varies from one person to another and from one application to another, the darkness of the tattoo is consider to signify the extent of the good luck. In other words, the darker the henna tattoo, the better your luck will be. So the theory goes.

Most henna tattoos are put on the hands and feet. This is because the skin here tends to be thicker, so it will absorb more of the henna, and the resulting tattoo looks darker than it would elsewhere.

Back of the hand and top of the feet works best because it's easier to keep from disturbing the henna paste as it dries and interrupting the process by which the paste stains your skin. But people do put henna tattoos in lots of places--palms, shoulders, calves, bellies, etc.

This henna tattoo starts on the fingers, descends down the palm, and onto the wrist. You can see how the tattoo is darker on the fingers and palm than it is on the wrist. This is because the skin on the wrist is thinner and doesn't take up the stain as well as on the hand.
(Photo from Ohio Body Art)

What It's Made of

Most henna artists mix the powder into a paste. Typical ingredients include:

henna powder
black tea or coffee
lemon juice or lime juice or orange juice or vinegar (mild citric or acetic acid)
sometimes the lemon juice etc. is mixed with sugar

That's it. People say the resulting paste feels like toothpaste. In my very limited experience, the paste that was put on me felt smoother even than toothpaste. More like gel toothpaste.

The henna plant is not toxic, and neither are any of those above ingredients. (The situation is a little different for "black" henna, but I'll get to that in a bit.)

The paste is applied to your skin, usually through a tiny little tube, sort of like a minuscule cake decorating tip. There are no needles, nothing is injected into your skin, it is not a painful experience at all. In fact, it's rather soothing.

This applicator is like what my henna tattoo artist used. Most of the applicator is a slender metal cone which tapers to a fine point with a hole in the end. At the top end of the applicator is essentially a plastic bag containing the henna paste. The artist squeezes the bag which makes the paste come out the tiny little hole at the bottom. The artist moves the applicator while squeezing out the paste. Often the artist makes very detailed designs and fine lines. I was pretty impressed with the delicacy of the skill.
(Photo from ehow)

This is another type of henna applicator. Here, instead of a little plastic bag, the receptacle that holds the paste is a plastic bottle. The tip of the bottle is the very fine tube with a tiny hole at the end through which the henna paste emerges as it is squeezed out and applied to the skin.
(Photo from Wikimedia Commons)

Since nothing is injected into your skin, some people say it's technically not a tattoo.

The stain sinks down into only the first few layers of your skin, all of which are dead skin cells. As these skin cells are naturally worn away, so also will the henna tattoo. That's why it only lasts a couple of weeks.

The Application Process

The paste goes on black. You leave it on, allowing the paste to dry and so the stain has time to sink into your skin.

Henna paste being applied. Here you can see how it sits on top of the skin.
(Photo from White Ink Tattoo Center)

You'll want to let the paste dry for anywhere from 4-8 hours. The range of time depends on the mixture your artist is using, how hot & humid the weather is, if you've got lotion on your hands (or wherever the tattoo was applied), etc.

This means you won't want to wet your hand--or foot or wherever you got the tattoo--during that drying time. So this is why people tend to get their henna tattoo on their non-dominant hand.

You'll also want to avoid brushing it against things, which will rub the paste off, or flexing and moving that part of your body very much.

When the paste dries, it will flake off in bits. Some of those bits got on my sheets and left faint brown stains. I washed my sheets right away and the stain came out, no problem.

After the dried paste flakes away, the brown stain on your skin will become visible. Over the next day or two, the brown stain will continue to darken somewhat.

You'll still want to avoid washing the area that's been tattooed for about 24 hours. After that, you can wash your hand, but you'll want to avoid any vigorous scrubbing. The more scrubbing, the more of those dead skin cells you'll wash away, and the faster your tattoo will fade.

Process of a henna tattoo, from paste to no-paste to additional darkening.
(Image from New World Henna)

This is what the paste looks like as it's drying & flaking off -- kind of crusty.
(Photo from Cuded)

Some of the designs can be really elaborate.
(Photo from White Ink Tattoos Center)

Or even more elaborate. This person would have to keep from moving both of her hands for several hours in order for this tattoo to turn out properly.
(Photo from ehow)

Henna on feet & toes -- also very detailed.
(Photo from Lovetoknow Tattoos)

Some pregnant women get henna tattoos on their bellies--I suppose in hopes of giving good luck to their forthcoming babies.
(Photo from Pop Sugar)

This might be a cool idea for someone going through chemo.
(Photo from Best Tattoo Designs Ideas)

Black Henna

In most photos of henna tattoos online, the henna looks black. I'm going to assume that this is probably because the picture was taken right after the henna was applied, before the paste dried.

However, there is a thing people call black henna. This type of henna leaves behind a much darker, blacker stain after the paste dries and flakes off.

The ingredient that gets added to the henna that turns it black is a chemical called paraphenylenediamine, or p-phenylenediamine, or PPD.

Regular Daily Apple readers will remember encountering this chemical in my entry on whether hair dye makes your hair fall out.

PPD is a type of coal tar that's been used for many years in hair dye, especially for brunette & black dyes.

Some people are allergic to PPD. If you are allergic to PPD, you do not want this stuff to touch your skin. It is possible to develop an allergy to PPD after having been exposed to it over time. This is why the hair dye people want you to do a skin test before each self-dyeing session, to make sure you haven't developed a PPD allergy.

But since henna is used to dye hair as well as skin, people thought, why not add the PPD that we've been using in hair dye to the henna, to make it darker?

It turns out, this isn't such a hot idea because for those people who are allergic to PPD, they experience some pretty unpleasant results with the black henna tattoos.

You can see that this woman from Kuwait got a really beautiful henna tattoo. Except the henna that was used had PPD in it, and she turned out to be allergic to PPD. So her skin turned red and swelled up every place the black henna was applied.

(Photo from Evans et al., New England Journal of Medicine)

Since it takes quite a few hours for the henna to soak into the skin, it can also take that long before people discover they are allergic to the PPD in black henna. So, often the artist using black henna does not know if one of his or her clients has had a bad reaction to the black henna.

The best thing to do, therefore, is to ask your henna artist if he or she uses black henna. If you know you're allergic to PPD, ask if he or she would use the regular henna instead.

If you get a black henna tattoo and then discover you're allergic because your hand is tingling and itching and swelling up like a beautifully decorated basketball, go to your doctor as soon as possible. Most likely, your doctor will prescribe some sort of steroid that will take down the swelling.

If the reaction and the swelling are severe, you could wind up with permanent pigmentation -- your temporary black henna tattoo would become permanent.