Washing wool and delicates without irritating your skin

Canadian winters mean sweaters, scarves, wool socks and thermal layers, and for many people, a winter of itching. Is it the wool, the way it was washed, or both? The answer is often a bit of each. Here’s what makes wool itch, how to wash wool and delicates gently, and how to keep your laundry routine from adding to the problem.

Why wool itches: prickle, not allergy

Most people who say they’re “allergic to wool” are describing a prickly, scratchy feeling. A 2017 review in Acta Dermato-Venereologica, by dermatologists and allergy researchers in Australia, looked at a century of published research and concluded that current evidence doesn’t suggest wool fibre is a skin allergen.

The itch is mechanical. Wool fibres come in different thicknesses. The review explains that fibres about 30 to 32 micrometres or thicker (a micrometre is a thousandth of a millimetre) are stiff enough that their ends press on the skin with enough force to trigger the nerve fibres that signal itch. Garments made mostly of fibres under about 19 micrometres weren’t perceived as prickly.

That’s why a coarse knit sweater can feel unbearable while a fine merino base layer feels fine. It’s the diameter of the fibre, not the sheep.

What about lanolin and other chemicals?

Lanolin is the natural grease in sheep’s wool, and some people do have a true contact allergy to it. But the same review notes that modern wool processing removes most lanolin, to less than 0.5 percent, and that dyeing and finishing reduce it further. It judged lanolin allergy from wearing modern wool garments very unlikely, and the same for older concerns about chromium and formaldehyde from processing.

So if a wool garment bothers you, the likeliest explanations are, in order:

• coarse fibres that prickle
• irritated or eczema-prone skin that reacts to any rough texture
• something left in the fabric, like fragrance from a wash product

Eczema and wool: it’s more nuanced than “avoid it”

Traditional advice is simple: no wool for eczema. The Eczema Society of Canada notes that for some people, itchy wool clothing can trigger eczema, and it recommends loose, breathable clothes in fabrics like cotton, avoiding scratchy materials. That’s sound, practical advice.

But fine wool is not the same as scratchy wool. A small Australian trial published in the British Journal of Dermatology dressed 39 children aged 4 weeks to 3 years with mild to moderate eczema in either superfine merino or their usual cotton for six weeks, then switched. Eczema scores were lower during the merino weeks, and steroid use on the body dropped.

Two cautions. The study was small, and it came from the same research group that wrote the wool review. So it’s a promising signal, not a new rule. If wool obviously bothers your skin, believe your skin.

How to wash wool without damaging it

Wool and silk are protein fibres. Wool is made mainly of keratin, the same kind of protein as your hair. That matters for three reasons.

Enzymes. Many everyday detergents contain protease, an enzyme that breaks down protein stains like blood and grass. An information page from a cleaning-products industry association points out that protease can’t tell the difference between a stain and a protein fibre. Laboratory research on wool processing confirms that protease digests wool keratin, and that uncontrolled exposure causes weight and strength loss in the fibres. Damaged fibres feel rougher.

Heat and agitation. The industry page explains that protein fibres swell in water, detergent lets them slide past each other, agitation tangles them, and as the fabric dries the fibres lock in place. That’s felting and shrinkage. The wool research notes that the scales on each fibre make wool especially prone to felting in a washing machine.

Lanolin. Strong detergents strip what little natural lubrication remains, which is one reason mild products are recommended.

In practice:

• Use a mild detergent made for wool or delicates, or at least one without protease in the ingredients.
• Wash in cool water, by hand or on a wool or hand-wash cycle.
• Squeeze, don’t wring. Press water out gently, or roll the item in a towel.
• Dry flat, reshaped, away from direct heat. Skip the dryer unless the label says otherwise.
• Wash when it needs it. Many people air wool out between wears and wash it only when it’s soiled or smells, which also means less wear on the fibres.

Keeping wash residue off sensitive skin

Wool and delicate washes have their own residue questions.

• No-rinse washes are designed to stay in the fabric. That’s convenient, but it means everything in the formula, including any fragrance, stays against your skin. For base layers, socks or anything worn by someone with eczema, a quick cool rinse is a simple fix.
• Fragrance is common in wool washes. If someone in the house has reactive skin or a fragrance allergy, choose a fragrance-free one. You can browse fragrance-free laundry products the panel has reviewed.
• Lanolin-enriched washes can be nice for the wool, but if you know you’re allergic to lanolin, check the label and skip them.
• Softener isn’t needed for wool, and it adds another coating to fabric that sits on your skin.

When the itch isn’t about wool

If a garment keeps bothering you after a gentle wash and a rinse, look at what else is going on. Is it tight, synthetic or trapping sweat? Is your skin dry from winter air and hot showers? A daily moisturizer is worth adding before blaming the fabric. The Eczema Society of Canada suggests keeping a simple trigger chart to spot patterns.

If you get a rash in a pattern that matches where clothing touches, or it doesn’t settle within two weeks after you stop wearing the item, see your doctor or pharmacist. A rash that sits exactly under waistbands, collars or armpits can point to something in the fabric itself, such as a dye or finish, and patch testing can help identify it.

What to remember: wool itch is usually about coarse fibres, not allergy, and fine merino is a different experience from a rough sweater. Wash wool and silk cool and gently with a mild, protease-free detergent, dry them flat, and rinse out no-rinse products if the item touches sensitive skin. Choosing fragrance-free products for these items is an easy win.