Are silk pillowcases hypoallergenic? Dust mites and allergens

Silk is often sold as hypoallergenic, and as a fabric dust mites stay away from. We went looking for the studies behind both claims and could not find them. No study has tested a silk pillowcase for allergies or for dust mites. Silk proteins can even cause allergies themselves, in rare cases. Here is what is known, and what it means for your bedding.

Are silk pillowcases hypoallergenic?

No test of plain woven silk supports that word. We found no study of a silk pillowcase and allergies at all. What we did find points the other way: silk proteins are documented allergens.

That does not make silk a common problem. Most reported reactions involve silk filling in quilts, silk waste or raw silk, not smooth finished fabric. Reactions to finished woven silk appear rare. But rare is not the same as hypoallergenic.

"Hypoallergenic" has no legal definition in UK textile rules. UK advertising rules still apply to it, though. They say a business must hold documentary evidence for a claim like this before it runs, and health claims need evidence from trials on people where relevant. Nobody has run that trial for a silk pillowcase.

Do silk pillowcases keep dust mites away?

No study shows that. We found no test of silk pillowcases, or of woven silk at all, for dust-mite resistance. The usual explanations, that mites "cannot digest silk" or that silk's "tight weave" keeps them out, come from retailers. None of them comes with any data.

There is research on what does stop mite allergen passing through fabric, and it is about pore size. A 1999 study of bedding encasement materials found that blocking mite allergen came down to very fine pores, below 10 micrometres. Nobody has measured the pore size of silk charmeuse, so there is no way to say how it compares.

There is a bigger problem with the idea. Dust mites live mainly in the pillow filling, not on its cover. An encasement is made to seal the pillow itself. A pillowcase is not an encasement, whatever it is woven from, so the weave of the cover is not the thing to judge it on.

Can you be allergic to silk?

Yes, though it is rare. The evidence comes from a handful of studies and case reports, and most of them involve silk in forms you would not sleep on.

• In Switzerland, a 1985 study traced night-time asthma to quilts filled with silk waste. The allergen came from silkworm material and insect contamination in the filling.
• In Beijing, a 1990 report described 64 children with asthma caused by silk, mostly from silk-filled quilts and clothes.
• In India, a study of workers who reel raw silk found they were more often sensitised to silk allergen on skin-prick tests than people living nearby.
• A 2015 case report described hives from a silk shirt in a person with atopic skin.

Most of these cases involve quilt filling, silk waste or raw silk at work, which is a long way from a finished pillowcase. The clothing cases and the shirt show that finished silk can cause a reaction in some people too. If you have ever reacted to silk, talk to your GP before you sleep on it.

What is sericin, and does it matter?

Raw silk is two proteins. Fibroin is the fibre itself. Sericin is the gum that holds the strands together, about 25 to 30% of the protein. Sericin is a known allergen. It was reported as a work allergen in hairdressers in the 1960s, and it is why the specialist silks made for eczema are sericin-free.

Sericin is washed out in degumming before smooth silk fabric such as charmeuse is woven, so a finished silk pillowcase is mostly fibroin. Our guide to what mulberry silk is explains how it is reeled and finished. That is a fact about how silk is made. It is not evidence that a pillowcase is hypoallergenic, and we will not present it as one.

What can you do if dust mites or allergies bother you?

For an allergy or asthma, your GP or a pharmacist is the right person to ask, including about your bedding. A pillowcase is not a treatment, and we will not sell ours as one. The same goes for eczema, which we looked at in is silk good for eczema and sensitive skin.

For the pillowcase itself, wash it every week, whatever it is made of. If you sleep on silk, use cool water and a pH-neutral detergent with no enzymes or bleach, and dry it flat or hanging, out of direct sun. Our guide on how to wash a silk pillowcase goes through it step by step.

You will not see SOIEA called hypoallergenic, allergy friendly or dust-mite resistant. Those are on our list of claims we don't make, and the acne, eczema and allergy section of our science page lists the studies with their sources.

SOIEA is 100% mulberry silk at 22 momme, in champagne and blush, launching in December 2026 for the UK and Ireland. It is smooth and soft against your skin. Choose it because you love how it feels. See the pillowcase.