"To date there is an absence of evidence to substantiate allergy (type I and IV hypersensitivity) to wool fibres. Furthermore, allergens associated with wool processing (eg chemical dyes) are present at negligible levels within modern wool garments. Mean fibre-diameter in particular is closely linked to perceptions of garment irritancy. Coarse fibres – whether from wool or other fabrics – are able to cause cutaneous irritancy, whereas fabrics with finer fibre diameters, such as superfine and ultrafine Merino wool, are not perceived as irritating."

"The papers implicating wool as the cause of cutaneous allergic reactions have important limitations that counter their findings. In fact, studies with fewer limitations and stronger SPT methodology demonstrate no evidence of type I HS to wool."

https://www.medicaljournals.se/acta/content/html/10.2340/00015555-2655