Debunking the Myth of Wool Allergies

Wool and Skin and Wool and Babies

Think you're allergic to wool? Think again.

If I had a fiver for every time someone told me they were allergic to wool, or that wool and sheepskins are not safe for babies, I would be able to buy up most of the sheep farms in England, but I haven’t so, here I am writing this, hoping to debunk the myth.  

A growing body of scientific evidence is helping to make the clear link between wool and wellbeing. Nowhere does this translate so compellingly as when applie to babies and newborns.

As many of us know from our GCSE Biology, the skin is our body’s largest organ.

Less well known is the research shows that wool garments work actively with the layer of air between our skin and the garment, to manage humidity (i.e. sweat) and help keep us comfortable.

Wool Keeps Babies Warm

Keeping babies warm helps them stay healthy and comfortable – and happy... Babies use large amounts of energy to stay warm if they are in a cold environment or inadequately dressed. It helps babies keep up the energy reserves they need: researchers found that weight gain in underweight newborn babies was 61% higherwhen they slept on a wool underlay rather than cotton. [13]

... But Not TOO Warm

Being a protein-based fibre made of keratin (the same as human hair), wool helps regulate our body temperature, reducing risk of overheating. Fossil fuel-based plastic fabrics such as polyester, acrylic and nylon don't have this natural ability.

Wool, however, allows the skin to breathe naturally, helping prevent sweating and letting the body find a natural equilibrium.

Wool fibres are the most hygroscopic of all the common clothing fibres. Wool can absorb and desorb (release) 50% more moisture vapour than cotton, and as much as 30 times more than polyester.

Did you know?

Wool fibres create a microclimate for the body that can quickly adapt to changing situations

Wool clothing can retain or release heat and moisture allowing the body to remain comfortable whether conditions are hot, cold, dry or wet [11,12]

By absorbing moisture, wool reduces the amount of sweat on the body − Less sweat on skin means less body odour

Wool locks in odour compounds resulting in less smell coming from the garment [9,10]

But is wool an allergen?

Wool is in fact very rarely allergenic. We now know that what used to be called “wool allergy” is not actuaslly an allergy at all, but a reaction to coarser fibres coming into contact with nerve receptors in the skin. [3]

Wool Bedding Recognised as Asthma and Allergy Friendly

The independent, international certification body Allergy Standards Limited (ASL) has formally recognised wool bedding products as ‘asthma and allergy friendly.’ ASL cited peer-reviewed research which assessed impacts of wearing merino wool garments next to the skin by those with the most sensitive skin, including conditions such as eczema. They found a growing body of evidence to suggesting high quality, fine Merino wool is non-irritant and is of low risk to those with sensitive skin.” [1] 

Wool is not an allergen

The ASL certification also relies on a major study by an expert group of allergists, immunologists and dermatologists which reviewed 100 years of medical research and concluded there is no evidence that wool is an allergen.2

What the reviewers found, however, was proof that when skin irritation is not a result of the fibre used, rather it is caused by fabric itself. This is due to the coarse ends of fibres protruding from the fabric against the skin. Irritation of the skin is caused as readily by coarse synthetic fibres as natural ones.

Finer wools like Bluefaced Leicester, Merino, Cashmere and Alpaca are soft and gentle against the skin. In fact, garments made of “superfine” wool (wool with a mean diameter of ≤17.5 microns) have shown benefits to people suffering from eczema or atopic dermatitis in both children and adults.

The researchers noted moreover that allergens previously applied during textile processing are minimally present in wool garments today given current industry practices. Because of this research, the role of wool fibre diameter is now better understood and other studies have consistently shown that wearing wool garments with a mean fibre diameter ≤17.5 mm for 6 hours/day or more, for 6 weeks lessens the severity and symptoms of conditions such as atopic dermatitis (AD) and eczema.3-5

Patients reported significant reductions in symptoms of itchy, scratchy and painful skin4 and that bleeding, weeping/oozing, flaking and dry or rough skin decreased.[4] 

Fibre Ends and Fabric

Fabric is composed of fibres. A prickle sensation can occur when the ends of fibres within a fabric press against the skin, triggering nerve receptors. These sensations are not specific to wool fibres. Fabric made of any fibre can cause the sensation.

This graphic shows how the ends of coarser fibres trigger the nerve endings known as nociceptors. The nociceptor sends an electrical signal to the brain. If the brain receives enough of these signals from the same area of the skin, it interprets them as “prickle”.

This shows that it is the coarseness of the fibre end that causes irritation rather than the compound from which the fibre is made. So, a very fine wool fibre will not cause skin irritation, which is one of many reasons why merino base layers are so comfortable and popular

New Solutions for Symptoms of Atopic Dermatitis

Atopic dermatitis is a common chronic inflammatory skin condition that affects up to 28% of infants. [5] AD causes intense itch, sleep deprivation and can impact quality of life.[7,8]

There is no cure for AD and current management focuses on frequent use of emollients and topical steroids along with irritant avoidance. [8]

Importantly, the evolving body of research led by the wool industry, funded by  Australian Wool Innovation, leads to new solutions for those who suffer with AD.

The studies show that wearing superfine Merino wool base-layer apparel is associated with significant improvements in AD, as seen in clinical scoring tools including SCORAD, EASI and ADSI. These translate into equally significant improvements in quality of life scores (e.g. IDQOL and DLQI) in both children and adults.

Sources and References

1. Donovan, A (2020, July 28) New standard for bedding containing Merino Wool. Retrieved from https://www.allergystandards.com/news_events/new-standard-for-bedding-containing-merino-wool/
2. Zallmann, M. et al. Debunking the Myth of Wool Allergy, Acta Derm Venereol 2017; 97: 906–915 DOI: 10.2340/00015555-2655. Retrieved from https://www.medicaljournals.se/acta/content/abstract/10.2340/00015555-2655
3. Su JC, Dailey R, Zallmann M, Leins E, Taresch L, Donath S, Heah SS, Lowe AJ. Determining Effects of Superfine Sheep wool in INfantile Eczema (DESSINE): a randomized paediatric crossover study. Br J Dermatol. 2017 Jul;177(1):125-133. doi: 10.1111/bjd.15376. Epub 2017 Jun 12. PMID: 28182252. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28182252/.
4. An Investigator Blinded, Clinical Trial Assessing the Efficacy of Superfine Merino Wool Base Layer Garments (SMWBG) in Children with Atopic Dermatitis (AD) Measuring SCORAD, EASI, POEM and DSA Scores. Biomedical Journal of Scientific & Technical Research 2018 Vol 7 Issue 1. doi: 10.26717/BJSTR.2018.07.001450. Retrieved from https://biomedres.us/fulltexts/BJSTR.MS.ID.001450.php
5. Fowler JF Jr, Fowler LM, Lorenz D. Effects of Merino Wool on Atopic Dermatitis Using Clinical, Quality of Life, and Physiological Outcome Measures. Dermatitis. 2019 May/Jun;30(3):198-206. doi: 10.1097/DER.0000000000000449. PMID: 30864970; PMCID: PMC6554012. Retrieved from https://pubmed.ncbi.nlm.nih.gov/30864970/ Draaisma, Eelco & Garcia Marcos, Luis & Mallol, Javier & Solé, Dirceu & Perez-Fernandez, Virginia & Brand, Petrus. (2015).
6. A multinational study to compare prevalence of atopic dermatitis in the first year of life. Pediatric Allergy and Immunology. 26. 10.1111/pai.12388. Retrieved from https://www.researchgate.net/publication/274514782_A_multinational_study_to_compare_prevalence_of_atopic_dermatitis_in_the_first_year_of_life
7. Ramirez FD, Chen S, Langan SM, Prather AA, McCulloch CE, Kidd SA, Cabana MD, Chren MM, Abuabara K. Association of Atopic Dermatitis With Sleep Quality in Children. JAMA Pediatr. 2019 May 1;173(5):e190025. doi: 10.1001/jamapediatrics.2019.0025. Epub 2019 May 6. PMID: 30830151; PMCID: PMC6503516. Retrieved from https://pubmed.ncbi.nlm.nih.gov/30830151/
8. Weidinger S, Novak N. Atopic dermatitis. The Lancet vol 387, Issue 10023, P 1109-1122, 12 March 2016 DOI: https://doi.org/10.1016/S0140-6736(15)00149-X. From https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(15)00149-X/fulltext
9. Laing R., Swan P. (2016) Wool in Human Health and Well-Being. In: Fangueiro R., Rana S. (eds) Natural Fibres: Advances in Science and Technology Towards Industrial Applications. RILEM Bookseries, vol 12. Springer, Dordrecht
10. Sweating and body odour symptoms & causes, Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/sweating-and-body-odor/symptoms-causes/syc-20353895 (accessed 27/11/2018)
11. , L, Harnett., P.R. and Palin., M.J., 1987, The influence of fibre and fabric type on thermophysiological comfort, Melliand Textilberichte 68, pp. 878-888
12. Cone, L. Gene, 2009, Minimize Heat Stress, Chilton’s Industrial Safety and Hygiene News, Volume 43, Issue 4, pp 39

13. R. Laing and P. Swan, Wool in Human Health and Well-Being, Natural Fibres: Advances in Science and Technology Towards Industrial Applications (Springer, The Netherlands, 2016) pp 19-34.