Constantly aware of hairs in particular region of face

Question

Our bodies grow hair in various places, but normally we don't notice the sensation of our own hairs resting on our skin. It seems like the brain filters this out (probably to preserve our sanity!)

Every once in a while, maybe once or twice a year, I'll go through a period where I can feel some of the hairs on my left eyebrow touching the skin there. When this happens, I can feel it all day, every day, for a few weeks. It feels as if a hair is curled the wrong way and that I could fix it by simply smoothing out the eyebrow, but if I touch it or try to smooth it, the sensation only becomes more noticeable. This always happens exclusively to my left eyebrow, never the right.

This time I'm also noticing that I can feel some of the hairs on the edge of my scalp nearest my left eyebrow. Brushing the hair in this area with my finger seems to help for a few seconds, but the sensation returns quickly.

Is there a name for such a condition? I've been trying to research it, but so far when trying to search it all I've found is people who obsessive-compulsively stroke their eyebrows, which I don't think is the same issue as what I'm experiencing.

Answer 1

Yes, there is a name for this. It is a paresthesia.

In layman's terms, a paresthesia is defined as:

A skin sensation, such as burning, prickling, itching, or tingling, with no apparent physical cause. (American Heritage Dictionary of the English Language)

If the sensation were relieved as long as the hair wasn't touching the skin in an unusual way, it would be a true sensation. True sensations wane, though. If you burn toast, you will smell it strongly initially, but soon the smell fades, even if still present, because our sensory system evolved to notice change over presence.

Repeated or prolonged exposure to an odorant typically leads to stimulus-specific decreases in olfactory sensitivity to that odorant, but sensitivity recovers over time in the absence of further exposure.

The loss of sensation is caused by sensory adaptation. If sensory adaptation were not possible, we would feel everything all the time, not ideal for stress-free survival.

Paresthesias are a different matter. Some paresthsias are familiar to all of us: a foot falling asleep after crossing our legs too long, or the tingling of a spot on the lip before a cold sore breaks out.

However, paresthesias can result from some minor pressure or disruption of a single sensory nerve, and they can last from hours to days, they can come and go, and they can be very irritating.

Paresthesias may be present in a wide variety of conditions ranging from vitamin deficiencies to serious illnesses like diabetes, multiple sclerosis, etc. These tend to be caused by nerve damage. Hypocalcemia, hyperventilation, migraines, inflammation, and a wide variety of other "insults" can cause paresthesias as well.

Many people experience the kind of paresthesias you describe (albeit in different places), and an etiology will not be found. Often they are benign. However, when in doubt, ask your doctor. The specialist who probably most commonly deals with paresthesias is a neurologist.

_{Psychophysical and Behavioral Characteristics of Olfactory Adaptation
NINDS Paresthesia Information Page}