The Curious Case of the Missing Eyebrow

Sometimes the symptom that brings a patient into the clinic is not the problem itself.

Sometimes, it is the clue.

This was the case with an eight-year-old girl who came into the clinic because one very noticeable thing was happening:

Her eyebrow was falling out.

Her mother had already taken her to the doctor, who referred her to a specialist to investigate possible alopecia. Understandably, the family wanted to know why an otherwise healthy young girl was suddenly losing her eyebrow.

Rather than looking only at the hair follicle, we decided to look at the bigger picture.

The Investigation Begins

We performed a Hair Tissue Mineral Analysis (HTMA), which gave us another piece of the puzzle: copper was elevated on the hair mineral analysis.

One of the things I love about HTMA, especially when working with children, is that it is non-invasive. There are no needles, no blood draws and no stressful medical procedures.

In fact, while we were taking the small hair sample, this little patient was happily eating watermelon.

It was a much easier experience for her than having blood drawn, and we were still able to gather another piece of information to help guide our investigation.

And that information immediately raised a question:

Where was the copper coming from?

Copper is an essential mineral. The body needs it. But, as with many things in biology, more isn't necessarily better.

So we started looking at possible sources of exposure.

Was she getting too much copper from her diet?

Was there an environmental exposure?

Could this have been something she had been exposed to from birth?

Was there a maternal history of copper supplementation or a copper IUD?

Or was there something in the environment that everyone had overlooked?

Then we asked about the family's water.

And that was when the investigation took an interesting turn.

The Hidden Source: The Water

The family had copper plumbing.

This is not unusual. Copper is commonly used in household plumbing, and Health Canada notes that copper can enter drinking water through corrosion and leaching from copper pipes and other plumbing components. The amount released can depend on factors including the chemistry of the water, the age of the plumbing, and how long water sits in the pipes.

The family already had a reverse-osmosis system.

But there was one problem:

They weren't using the RO water for cooking.

The family was using regular tap water for food preparation, meaning that even though they had a filtration system, they hadn't eliminated that potential source of exposure.

So they made a simple change:

They began using their treated water for drinking and cooking.

Health Canada specifically recognizes reverse osmosis as one of the household treatment options that can remove copper from drinking water. It also recommends point-of-use treatment at the tap used most often for drinking and food preparation when copper exposure is a concern.

But we weren't finished.

Why Zinc Entered the Picture

The next question was:

What do we do while the body is dealing with an elevated copper burden?

One of the nutrients we considered was zinc.

Copper and zinc have a complicated relationship. They are both essential minerals, but they also interact with one another in the body. In particular, increased zinc availability can influence copper absorption through a protein called metallothionein, which binds copper in intestinal cells and can reduce the amount of copper that reaches the circulation.

This is one reason zinc has historically been used therapeutically to reduce copper absorption in specific medical conditions such as Wilson disease.

In this particular case, zinc was used as a temporary nutritional support strategy, alongside addressing what we believed was the more important issue:

Remove the potential source.

The goal wasn't to use a supplement to compensate for an environmental exposure.

The goal was to change the exposure while supporting mineral balance during the transition.

But What Does Copper Have to Do With Hair?

This is where the story gets particularly interesting.

Zinc is essential for normal skin biology and the rapidly dividing cells of the hair follicle. Significant zinc deficiency is a recognized cause of hair loss, and eyebrow and eyelash alopecia have specifically been reported in association with zinc deficiency.

There is also evidence that zinc and copper can antagonize one another.

In other words, the question isn't simply:

"Is copper high?"

It is also:

"What is happening to zinc?"

The relationship between the two minerals is complex. Higher copper exposure can interfere with zinc absorption in experimental models, while zinc itself influences copper absorption through metallothionein.

And zinc matters to hair because hair follicles are among the body's most rapidly dividing tissues. When zinc deficiency is significant, hair loss can occur. A review of nutritional factors in hair loss identifies zinc deficiency as a recognized cause of alopecia, and clinical reports have documented hair regrowth after correcting zinc deficiency.

So the working hypothesis in this case was not simply:

High copper = missing eyebrow.

It was more nuanced:

Potentially excessive copper exposure → disruption of copper/zinc balance → impaired zinc availability or function → stress on the hair follicle → hair loss.

That is a biologically plausible pathway, but it is important to distinguish a plausible mechanism from proof of causation.

There are many causes of eyebrow loss, including alopecia areata, nutritional deficiencies, thyroid disorders, dermatologic conditions, trauma and other medical conditions. That's why appropriate medical evaluation remains important when a child develops unexplained hair loss.

One Month Later…

Then came the phone call every practitioner loves.

A month after making the changes, the girl's mother reported that the eyebrow was growing back.

The visible symptom was beginning to reverse.

We can't say from this single case that copper from the household plumbing definitively caused the eyebrow loss. There was no controlled experiment, and hair regrowth can have multiple explanations.

But the timeline was certainly intriguing.

The family had identified and reduced a potential environmental source of copper exposure.

They had changed the water they were using for drinking and cooking.

They had temporarily supported zinc.

And one month later, the eyebrow was growing again.

The Bigger Lesson

This case reminded me of something I see repeatedly in clinical practice:

Sometimes the answer isn't in the symptom. It's in the environment surrounding the symptom.

An eyebrow falling out can send you looking for an autoimmune condition.

And sometimes that is exactly what you find.

But sometimes you need to keep asking questions.

What is she eating?

What supplements is she taking?

What medications or products is she exposed to?

What is in the water?

What is in the home?

What changed before the symptom appeared?

And perhaps most importantly:

Where is the mineral coming from?

Because finding an imbalance is only half of the investigation.

The more important question may be:

Why is it there in the first place?

In this case, the missing eyebrow became the clue that led us all the way back to the kitchen tap.

And sometimes, that's where the real case begins.

References

• Health Canada. Guidelines for Canadian Drinking Water Quality – Copper. Health Canada explains that copper can enter household drinking water through corrosion of copper plumbing and provides guidance on reducing exposure and using certified treatment devices.

• Ogawa Y, Kinoshita M, Shimada S, Kawamura T. Zinc and skin biology. Archives of Biochemistry and Biophysics. 2018. Reviews zinc's role in skin biology and its relationship with alopecia.

• Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatology and Therapy. 2019. Reviews the evidence connecting nutritional deficiencies, including zinc deficiency, with hair loss.

• Eyebrow and Eyelash Alopecia: A Clinical Review. This review discusses nutritional causes of eyebrow and eyelash loss, including zinc deficiency, as well as other differential diagnoses.

• National Center for Biotechnology Information. Toxicological Profile for Copper. Reviews copper interactions with other minerals, including zinc, and the role of intestinal metallothionein.