Insulation has a reputation for being quite an itchy material. Many people are surprised when they still itch hours or even days after exposure to the insulation. However, this is quite a normal response.
How itchy insulation makes you and how long this sensation lasts depends on a number of factors that influence the extent of the body’s biological response to these irritants. It’s also important to know that while itching is a normal reaction to irritation, it can itself become harmful.
The duration of an itching response to insulation material can last between a few hours to several days or even more. It depends on the type of insulation material, the level of exposure, individual sensitivity, and how the itching is dealt with.
Insulation Irritation Causes an Immune Response
The reason that you itch when you come into contact with certain types of insulation is because the irritation (chemical and/or mechanical) causes an immune response. This involves the release of chemicals from mast cells that trigger certain nerve fibers in the affected area.
The nerve endings send signals to your brain that the area is itchy. The goal is to get you to scratch at the area and hopefully dislodge or otherwise remove whatever is causing the irritation.
Itching Reaction Lasts After Contact Stops
When you remove the stimulus that is causing the itching, you do not immediately halt the immune response.
The chemicals that are released are still circulating, and the nerve fibers are still activated as a result.
How long they stay in the system and remain activated depends on a number of factors.
The Insulation Type
Some insulation types are more likely to cause itching, like fiberglass, mineral wool, cellulose, and spray foam insulation.
Other insulation types have the potential to cause itching, but it will take greater exposure or a pre-existing dermal sensitivity. Wool, hemp, and straw insulation fall into this category.
These can cause mechanical irritation because they consist of fibers, which have some level of abrasiveness (although they are softer than fiberglass and mineral wool). In addition, they are sometimes treated with chemicals that can also irritate the skin.
If you are exposed to one of the itchier insulation materials, the immune response is more marked, so more chemicals are released, which can activate the nerve fibers longer.
Furthermore, because they are harsher on the skin, the initial irritation is more likely to cause damage. When the insulation is removed, this damage sustains the immune response, which also sustains the itchy sensation.
Level of Exposure
There are two factors to consider when it comes to the level of exposure:
- How much insulation you are exposed to
- How long you are exposed to it
If you enter your attic to fetch something out of storage and your hand brushes over some fiberglass insulation, then you might have some itching at the site, but it will probably not last very long once your hand is no longer touching the fibers.
Were you to root around in the fiberglass looking for some electrical wires, the amount of insulation in contact with your skin at a time is more likely to trigger a full-blown immune response leading to itching that lasts longer than the contact.
Then the duration matters because the longer you are exposed to any level of insulation, the more likely it is for the insulation to penetrate the dermal barrier, so the body mounts a significant counterattack.
The body recognizes that the initial immune response did not stop the contact, so it escalates the reaction, leading to increased levels of chemical mediators and nerve activation, which takes longer to stop.
If you are prone to dermal irritation, then your body is primed to initiate the itch response.
I suffer quite badly from skin allergies, so I am always a little itchy. Shaving can trigger an itch response that lasts for a full week and washing my hands with a fragranced hand soap can give me eczema and itching that would last indefinitely unless I treat it with cortisone cream.
People with this kind of generalized sensitivity or with an allergy to a particular chemical found in the insulation will have a more extreme initial response to the insulation irritation because it is viewed by the body as a greater threat than it would be to other people who are not sensitive.
Again, the stronger the response the more chemicals are released, which trigger the never fibers for longer, which means that you itch for longer.
How You Respond to the Itching
While scratching is supposed to remove the irritant from your skin, there is a point at which it causes more harm than good. Basically, scratching can make you itchier for longer.
The reason for this is that when you scratch, you are damaging your skin to a certain extent. If you scratch vigorously or long enough, then your body starts to mount an immune response to the damage that this is causing.
Of course, part of this immune response would be the release of chemical inflammatory mediators, which can cause more itching (your body tries to stop the irritation in the same way as before, not realizing that the irritants are your own fingers/nails).
The result is a nightmarish feedback loop. If left to continue looping, people can end up scratching their skin until it bruises or breaks.
To avoid this, instead of scratching, you should wipe the area with a cool, damp cloth to remove the insulation fibers or chemicals from your skin.
Typical Itch Duration
Brief and slight exposure may not even cause itching, particularly if the insulation material is not one of the itchier ones. If it does cause enough irritation to trigger an immune response, the itching is not likely to last longer than a few hours to a day or two.
Greater exposure, particularly to the itchier insulation materials, or an existing sensitivity can lead to several days of itching—maybe even more if you don’t treat it properly.
If the itching is lasting more than two days, especially if you have tried some self-treatment techniques, then you should seek medical advice and assistance.
First you want to make sure that the insulation is definitely off of your skin:
- Remove any remaining visible insulation particles from the skin
- Gently wash the affected area with cool, soapy water (avoid fragranced soap, which can worsen the irritation)
- Apply over-the-counter hydrocortisone cream to reduce itching and inflammation
- Avoid scratching the area to prevent further irritation or infection
Once this is done, if itching persists, you can try the following:
- Applying a cold compress to the affected area
- Taking an over-the-counter antihistamine to reduce allergic reactions
- Using calamine lotion to soothe the skin (you don’t want to use cortisone cream for too long, use it for the initial treatment, then move to something less damaging for longer-term application unless directed otherwise by your health practitioner).