Wool can cause itching due to its natural structure and properties. The outer layer of wool fibers contains scales that can irritate the skin, causing an itchy sensation. Additionally, wool fibers can trap heat and moisture, creating a humid environment that can exacerbate the itchiness. Certain individuals may have heightened sensitivity to wool, experiencing more pronounced itching.

Composition and Structure of Wool

  • Wool: A Beloved Natural Fiber – Widely used in clothing, hats, outdoor gear, and more, wool is a cherished natural fiber due to its inherent positive properties.
  • Wool Fiber Thickness – The thickness of wool fibers can vary from 16.5 to over 40 micrometers, depending on the strength and quality of the fiber, the breed of the sheep, as well as their habitat.
  • Fine Wool for Comfort – Merino wool is known for its fine, crimped fibers with a thickness of only 16.5 to 24 micrometers, making them incredibly soft and not itchy when coming in contact with the skin.
  • Various Wool Types – Wool comes in various types, from the smooth and fine Merino to itchier, coarse fibers with a thicker, scaly surface texture.
  • Microns Matter – Wool with a thickness of more than 30 microns can cause itchiness, as they press on the human skin and excite nerve receptors.
  • The Itch-Free Merino – Thanks to its flexibility, smooth surface, and crimped structure, Merino wool fibers bend when touching the skin, reducing irritation and itchiness.

The Role of Keratin in Wool

  • Wool fibers derive from the outer layers of sheep’s skin and are composed of keratin, a protein that is also found in human hair and nails.
  • Keratin gives wool its unique properties, such as its resilience, natural crimp, and insulation abilities, which make it a versatile and cozy material for clothing.
  • The “scales” that cover wool fibers create a rough surface, which can help regulate moisture and provide additional warmth.
  • This natural variation in the surface of wool fibers can contribute to the itchiness some people experience, but the specific factors influencing this sensation vary.
  • When it comes to Merino wool, the fiber thickness is typically 17-20 microns, providing a softer, less irritating feeling on the skin.
  • Overall, the keratin present in wool offers numerous benefits in terms of comfort, insulation, and moisture regulation, but the texture might not be suitable for all individuals.

The Itch Factor: Causes and Factors

  • Type of Wool: Not all types of wool cause itchiness. Cheaper wool fibers, with longer and thicker fibers, tend to irritate the skin more than merino wool, which is known for its soft and non-itchy texture.
  • Fiber Length and Diameter: Shorter, coarser fibers cause an itchy feeling as they rub against the skin. Merino wool, on the other hand, has lengthy and soft fibers that are comfortable to wear.
  • Lanolin: A natural waxy coating found on wool fibers, lanolin could cause an allergic reaction in a small percentage of people, leading to itchiness.
  • Chemicals and Dyes: Sometimes, itchiness could be caused by chemicals and dyes used on the wool, especially in cheaper products.
  • Skin Sensitivity: Not all people have the same sensitivity to wool; those with sensitive skin might experience itchiness to a greater extent.

The Science Behind Itch Sensation

In the quest to understand the science behind the itch sensation, several breakthrough discoveries have been made. Here are some key insights:

  • Johns Hopkins researchers have found specific nerve cells in mice that sense itch but not pain, which could help in developing treatments for chronic itching conditions.
    • Itch and pain sensations are both essential for survival but can become detrimental when they persist for long periods.
    • Sensory nerve cells have both pain and itch receptors on their surfaces, and nerve cells with the itchy receptor MrgA3 transmit electrical signals that are interpreted by the brain as itch.
    • According to a study published in an NLM database, C fibers in primary afferent neurons are the primary mediators of itch sensation, with recent evidence suggesting that A fibers are also involved in itch perception.
    • While itch has historically been considered a submodality of pain, studies in the neuroscience of itching reveal differences in the underlying molecules, cells, and circuits mediating the sensations.

Understanding Skin Sensitivity

  • Skin sensitivity is a common issue faced by many people, which can be triggered by various factors such as environmental, lifestyle, and even the clothing materials they wear.
    • People with certain skin conditions, like eczema or atopic dermatitis, are more susceptible to irritation from materials like wool.
    • Skin sensitivity and itchiness can be influenced by factors like thickness of the skin, age, temperature, and moisture levels on the skin.
    • Wool fibers have a scaly surface that can lead to irritation when in contact with the skin.
    • The average thickness of normal virgin wool is around 37-40 micrometers. The human sensitivity threshold lies at around 25-30 micrometers.
    • Understanding one’s skin sensitivity is important in order to find clothing materials and solutions to minimize discomfort and itching.

Factors Influencing Wool Itch

  • Quality of wool: Low-quality wool with thick fibers can cause itching, while high-quality wool like Merino is finer, softer, and less likely to cause discomfort.
  • Fiber diameter: Larger diameter fibers lead to itchier wool, while smaller diameter fibers feel softer on the skin.
  • Animal source: Different animals produce different types of wool with distinctive characteristics, which may influence how itchy the fabric feels.
  • Lanolin content: Wool allergies, often caused by naturally occurring lanolin, can lead to itching.
  • Presence of synthetic fibers: Wool mixed with synthetic fibers may be less breathable and cause increased sweating or rashes, leading to itching.

Solutions for Minimizing Wool Itch

  • Opt for high-quality Merino wool: Unlike traditional wool, Merino wool has finer fibers that are soft and comfy, ensuring a non-itchy experience. Always check the label and choose products made with 100% Merino wool.
  • Wash new woolen items: Before wearing wool items for the first time, wash them according to the care instructions. This can soften the fibers and reduce itchiness.
  • Layer up: Wearing a soft, thin layer under your woolen clothing can provide a barrier that prevents itchiness. Opt for materials like cotton, silk, or smooth synthetic fabrics.
  • Keep your skin moisturized: Dry skin can exacerbate the itchiness from wool. Regularly applying moisturizer can help keep the skin hydrated and reduce the itch.
  • Look for hypoallergenic wool products: Some brands offer hypoallergenic woolen items that undergo a special treatment to reduce the chances of itching, making them suitable for sensitive skin.


In conclusion, the itchiness of wool can be attributed to various factors, including the specific breed of sheep the wool comes from, the diameter of the wool fibers, and the processing methods used. It is essential to consider these elements when choosing a wool garment to ensure optimal comfort. While some breeds of sheep produce softer wool with smaller micron counts, others produce rougher wool with higher micron counts, which leads to itchiness.




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