Conventional wisdom holds that patients with atopic dermatitis (AD) should shun wool clothing in favor of cotton or silk, because wool is said to be irritating and promote itching. But not so when the garments are made of fine-diameter fibers of merino wool, Joseph F. Fowler, Jr., MD, said at MedscapeLive’s annual Las Vegas Dermatology Seminar, held virtually.

“We’ve always though that wool is bad in atopics, right? Indeed, rough wool might be. But fine wool garments can actually improve atopic dermatitis, probably because wool is the most breathable fabric and has the best temperature regulation qualities of any fabric we can wear,” said Dr. Fowler, a dermatologist at the University of Louisville (Ky).

He was first author of a randomized, 12-week, crossover, assessor-blinded clinical trial which showed precisely that. And a second, similarly designed study, this one conducted in Australia, also concluded that fine merino wool assists in the management of AD.

The study by Dr. Fowler and coinvestigators included 50 children and adults with mild or moderate AD who either wore top-and-bottom base layer merino wool ensembles for 6 weeks and then switched to their regular nonwoolen clothing, or vice versa. The mean Eczema Area and Severity Index (EASI) score in those initially randomized to merino wool improved from a mean baseline of 4.5 to 1.7 at week 6, a significantly greater improvement than in the group wearing their regular clothing. Similarly, those who switched to merino wool after 6 weeks experienced a significant decrease in EASI scores from that point on to week 12, while those who switched from merino wool to their regular clothing did not.

Mean Dermatology Life Quality Index (DLQI) scores in patients who wore merino wool first improved from 6.9 at baseline to 3.4 at week 6. Those who wore their regular clothing first went from a mean baseline DLQI of 6.7 to 6.2 at week 6 – a nonsignificant change – but then improved to a week 12 mean DLQI of 3.7 while wearing wool. There was no improvement in DLQI scores while participants were wearing their regular clothing.

Static Investigator’s Global Assessment scores showed significantly greater improvement while patients wore merino wool garments than their regular clothing.

The Australian study included 39 patients with mild to moderate AD aged between 4 weeks and 3 years. This, too, was a 12-week, randomized, crossover, assessor-blinded clinical trial. Participating children wore merino wool for 6 weeks and cotton ensembles chosen by their parents for an equal time. The primary endpoint was change in the SCORing Atopic Dermatitis (SCORAD) index after each 6-week period. The mean 7.6-point greater SCORAD reduction at 6 weeks while wearing merino wool, compared with cotton, was “a pretty impressive reduction,” Dr. Fowler observed.

Reductions in the secondary endpoints of Atopic Dermatitis Severity Index and Infants’ Dermatitis Quality of Life Index while wearing merino wool followed suit. In contrast, switching from wool to cotton resulted in an increase in both scores. Also, use of topical corticosteroids was significantly reduced while patients wore merino wool.

Wool harvested from merino sheep is characterized by fine-diameter fibers. In Dr. Fowler’s study the mean fiber diameter was 17.5 mcm. This makes for a soft fabric with outstanding moisture absorbance capacity, a quality that’s beneficial in patients with AD, since their lesional skin loses the ability to regulate moisture, the dermatologist explained.

Both randomized trials were funded by Australian Wool Innovation and the Australian government.

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