For decades, wool has been cast as the villain in the wardrobe of anyone with eczema. Doctors, parents, and even sufferers themselves have long assumed that wool’s scratchy fibres are a surefire way to trigger the inflammation and unbearable itch that define the condition. But what if we need to look at this assumption more closely?

A growing body of research is prompting a re-evaluation of the belief that wool is inherently irritating to eczema-prone skin. Several studies suggest that superfine Merino wool may be well tolerated and, in some cases, may contribute to managing symptoms of atopic dermatitis.

One of the most comprehensive investigations into the wool-eczema connection comes from Zallmann et al., 2017 in Acta Dermato-Venereologica, a meta-study that examined 100 years of research on wool and skin irritation. It concludes that the issue isn’t wool itself but the diameter of the fibre. Coarse wool - anything with a fibre diameter above 30 microns - can provoke skin irritation by mechanically stimulating nerve endings. But superfine and ultrafine Merino wool (below 18.5 microns) has been shown to be well tolerated and, in some cases, even beneficial in eczema management.

Another important distinction is between irritation and allergy. While many assume their reaction to wool is due to an allergic response, the evidence suggests that true wool allergies (those mediated by the immune system) are rare. Instead, irritation is more often due to coarse fibres pressing into the skin rather than a specific allergic response.

Several clinical trials have examined the potential benefits of wool for eczema sufferers:

• Su et al. (2017) in the British Journal of Dermatology, tested superfine Merino wool garments on infants with eczema. After six weeks, the children wearing wool had significantly lower SCORAD (a standard measure of eczema severity) scores compared to those wearing cotton. For the Australian news feature on the findings, see film Melbourne study finds wool helps eczema sufferers.
• Spelman et al. (2018) conducted an investigator-blinded clinical trial focused on children aged 6-25 years. Those who wore superfine Merino wool base layers for 15 weeks saw reductions in itch, redness, and overall dermatitis severity.
• Fowler et al. (2019) observed that adult patients with atopic dermatitis who switched to superfine Merino wool reported reduced itch and a decreased need for topical steroids.

What makes wool different from other fabrics? Unlike synthetics (plastic), which can trap heat and moisture, or cotton, which absorbs but does not efficiently release moisture, superfine wool helps regulate humidity and temperature at the skin’s surface. This creates a more stable microenvironment that may support the skin barrier, a crucial factor in eczema management.

For those with eczema or sensitive skin, the above mentioned research has the following advice!

Suitable wool types near to skin:

• Superfine Merino wool: 15-18.5 microns (e.g., Devold Breeze - 17.5 microns)
• Ultrafine Merino wool: Below 15 microns

Avoid near to skin:

• Standard wool: 23+ microns
• Coarse wool: 30+ microns

Despite emerging evidence, many dermatologists remain cautious about wool due to long-standing perceptions. However, research differentiates between coarse wool, which can irritate, and superfine Merino wool, which studies suggest may be tolerable or even beneficial for some eczema sufferers.

For those who have avoided wool, the latest findings offer reason to reconsider. Textile choices matter, and superfine Merino wool may be a viable option for comfort and skin health.

A meta-study, or meta-analysis, is a research approach that systematically reviews and analyses multiple studies on a specific topic to identify patterns, trends, and overall conclusions. By aggregating data from various sources, meta-studies provide a higher level of evidence than individual studies alone.

The Zallmann et al. (2017) meta-study is methodologically sound because:

• It systematically reviewed 100 years of research, reducing biases that can occur in isolated studies.
• It distinguished between different wool types, particularly focusing on fibre diameter, which is a crucial factor in textile tolerability.
• It considered both historical and modern processing methods, acknowledging improvements in wool production that reduce irritation risks.