You put the earrings in. Within a day the lobe is pink. By day three it itches, then it weeps, and you take them out and go back to the pair you know is safe. Most people file this under sensitive ears and accept it as their lot.
It is almost never the diamond. It is the metal, and roughly nine times out of ten the specific culprit is nickel.
What is actually happening to your ear
Nickel allergy is the most common contact allergy there is. Estimates put it somewhere around one in six people, and it is markedly more common in women, largely because women get their ears pierced younger and more often. The reaction is called allergic contact dermatitis, and it is not a one-off event. It is a sensitisation: once your immune system has learned to react to nickel, it does not unlearn it. The reaction tends to get easier to trigger, not harder.
The reason it shows up in earrings specifically, and not in, say, a nickel-containing watch case, is that a piercing is a wound that never fully closes. The post sits inside your body, in contact with tissue and moisture, for hours at a stretch. Sweat and warmth pull metal ions out of the alloy and into the skin. That is why an earring can bother you when a ring in the same metal does not.
Which means the question is not "is this jewellery hypoallergenic", a term with no legal definition and no enforcement behind it. The question is: what is the post made of, and how much nickel is in it.
The metals, ranked by how well your skin will tolerate them
Platinum (PT950): the safest thing you can put through your ear
PT950 is 95% pure platinum. Platinum is naturally white, which matters more than it sounds: it does not need to be plated to look white, so there is no plating to wear through and expose whatever is underneath. It is dense, it is inert, and it is about as close to biologically boring as a metal gets. If you have reacted to everything, this is where you stop.
It is also the most expensive option, and it is heavier. Some people love the substance of that weight. Others find it noticeable in a long drop earring.
18K gold: high purity, and what matters is what fills the rest
18K means 75% pure gold. Gold itself is inert and essentially never the problem. The remaining 25% is alloy, added for strength and colour, and that alloy is where a reaction lives or dies.
18K yellow gold is typically alloyed with silver and copper, and is generally well tolerated. Rose gold gets its colour from a higher copper content, which is fine for most people. White gold is the one to watch, because white gold is yellow gold made pale, and historically the whitening agent of choice was nickel. Better white gold uses palladium instead. If your ears have ever objected to a white gold earring, nickel in the alloy is the first suspect, not the gold.
The step from 9K to 18K matters here too. 9K is only 37.5% gold, so there is nearly twice as much alloy in contact with your skin. Higher purity means less of everything else.
Sterling silver, platinum-plated (S925): the honest entry point
S925 is 92.5% silver. Silver is not a common allergen, and a platinum plating gives it a bright, cool, modern finish at a fraction of the cost of solid platinum. For most people it is perfectly comfortable.
Two things to be straight about, though. Plating is a surface, and surfaces wear. Over time and with friction it thins, and eventually you are in contact with the silver beneath rather than the platinum on top. And silver tarnishes: it reacts with sulphur in the air and in your skin, and it dislikes perfume, chlorine, hairspray and cleaning products with real conviction. S925 is a genuinely good option, and it asks more of you in return.
If your skin is already reactive and you want something you can put in and forget about, this is not the tier to start on.
The part everyone forgets: the back
People agonise over the post and then screw on whatever back came in the box. The back touches your skin too, and it sits against the softest part of the lobe for as long as the earring is in.
Check that the back is the same metal as the post. A platinum post with a cheap base-metal back is a platinum earring that will still make your ear itch, and it is a surprisingly common shortcut. It is worth asking the question outright before you buy, because nobody will volunteer the answer.
Buying earrings your ears will tolerate
Work down this list in order.
Ask what the post and the back are made of, by name, not by adjective. "Hypoallergenic" is a word, not a specification. PT950 and 18K are specifications.
If you have reacted before, skip white gold unless you can confirm it is palladium-alloyed rather than nickel-alloyed. Yellow gold and platinum are the low-drama choices.
Consider how long the earring is going to live in your ear. A pair you wear for an evening asks very little of your skin. A pair you sleep in, exercise in and shower in for months at a time is a much bigger test, and it deserves the better metal.
And take them out before the pool, the gym and the perfume. Not for your skin's sake, for the jewellery's.
Pieces that will not fight your skin
The ear cuff is worth a mention here for a different reason. It needs no piercing at all, so there is no wound and no post sitting inside your skin. If your lobes have simply had enough, it is a genuine way back into wearing diamonds.
The short version
Sensitive ears are usually a nickel allergy, and a nickel allergy is permanent. Platinum is the safest bet. 18K yellow gold is close behind. White gold is fine if it is alloyed with palladium and a problem if it is alloyed with nickel, so ask. Platinum-plated silver is a good, honest entry point that wants a bit more care in return. And check the back, because it touches you too.
