Vitiligo and Hashimotos: What is the connection?

What is vitiligo?

Vitiligo is a condition that causes some patches of your skin to lose color. This condition can not only cause some of your skin to lose its color but can actually also cause hair loss in certain areas of your body.

There are several causes of Vitiligo, however, it is considered to be an autoimmune condition where your melanocytes are destroyed.

In patients with vitiligo, their immune system creates antibodies that destroy melanocytes. Melanocytes are cells in your skin and eyes that produce melanin.

Melanin is a pigment that is produced by melanocytes that is responsible for giving color to your skin, hair, and eyes.

Vitiligo occurs in about 1% or slightly more of the population throughout the world. While vitiligo is generally considered autoimmune in origin, there may be several other outstanding factors that could be the culprit.

Some of these factors include genetics, stress (emotional and physical), neurogenic or self-destruction. In fact, alot of vitiligo cases are familial.

For the most part, vitiligo is a condition that primarily affects the skin, however, this may predispose individuals with vitiligo to other conditions.

Individuals with vitiligo may be at an increased risk for the following:

• Eye problems. While vision is not typically impaired, there may be some changes to the retina and iris of the eye.
• Increased sensitivity to sunlight and burns. This is because individuals with vitiligo lack melanocytes, increasing their chances of sunburning.
• Anxiety or depression. Because vitiligo can affect any part of the skin, some individuals may experience low self-esteem or anxiety regarding their skin.
• Other autoimmune conditions. As mentioned above vitiligo is considered to be an autoimmune condition where the immune system creates antibodies that destroy melanocytes. Typically when an individual has one autoimmune condition, they are predisposed to other autoimmune diseases. For this reason, an individual with vitiligo may be at an increased risk for Hashimotos, Pernicious Anemia, Alopecia Areata, Psoriasis, Type 1 Diabetes, Addison's Disease, etc. While it's been associated with a number of autoimmune conditions, Hashimoto's Thyroiditis is the most prevalent autoimmune disease found in patients with Vitiligo, with a co-morbidity greater than 30%.

How is vitiligo diagnosed?

While vitiligo is generally diagnosed clinically as the white patches can be visibly seen, a Wood's lamp may be used which will allow the healthcare provider to assess the skin under a UV light.

What's the connection between Hashimoto's and Vitiligo?

There have been several hypotheses on why the co-mobidity between Vitiligo and Hashimotos is so high.

As we know, in both diseases, there is oxidative stress in both, as well as an autoimmune attack of melanocytes (vitiligo) and thyrocytes (Hashimoto's thyroiditis). 

But why are these two diseases so connected?

Interestingly, thyroxine, the target molecule produced in the thyroid, and melanin, the target molecule produced in the skin are both derived from a specific molecule called tyrosine.

Because both conditions, like most autoimmune conditions, are associated with the activation of oxidative stress, the effect it has on tyrosine may account for the destruction of both melanocytes and thrycotes.

As mentioned earlier, there is also a genetic component that may be responsible for the destruction of melanocytes.

Similarly with Hashimotos Thyroiditis, there is both an autoimmune and a genetic component. There have been 37 susceptible genes that have been identified in Vitiligo and more than 15 genes that have been identified in autoimmune thyroid disease.

When assessing the susceptible genes amongst both conditions, there were 9 potential specific genes that were involved in both vitiligo and autoimmune thyroid disease. More specifically, TYR, Tg, and TSHR were gene associations found in both conditions.

Another gene, PTPN22 gene, which is responsible for encoding a lymphoid-specific phosphatase, was also seen in patients who had both autoimmune thyroid disease and vitiligo.

Also, AIS1, an autoimmunity susceptibility locus, was found to be the most probable reason for the comorbidity between Hashimoto's thyroiditis and vitiligo.

Interestingly, melanocyte-specific antigens were observed in patients who had Hashimoto's thyroiditis versus patients who did not have thyroid disease.

In patients with healthy thyroid function and in patients with Hashimoto's thyroiditis who did not have vitiligo, NKI/beteb, Pmel17, TRP-1, HMB-45, and S100 were negative whereasTRP-2, LAMP and CD69 were positive.

The TYR gene was only detected in the thyroid of patients with Hashimotos Thyroiditis, and levels of LAMP and CD69 were higher in patients with Hashimoto's thyroiditis versus patients with normal thyroid function.

Studies are showing that assessing melanocyte antigens in the thyroid of patients with Hashimoto's thyroiditis may give more indication of vitiligo in association with Hashimoto's.

By assessing different skin cells and their ability to express certain thyroid antigens like TSHR, thyroglobulin, and TPO, researchers are able to connect the effect that immune system activation can have on the thyroid and skin cells. 

Symptoms of Hashimoto's Thyroiditis include:

• brain fog
• weight gain
• hair loss
• Constipation
• Fatigue 
• dry skin
• muscle weakness
• swelling in your extremities
• joint stiffness

Does this mean I will get Hashimotos if I have vitiligo?

No, not necessarily. While research does show that there is a high co-mobility between Hashimoto's thyroiditis and vitiligo, it doesn’t mean that you will have both diseases. Instead, it means that you have a higher likelihood of developing Hashimoto's thyroiditis if you already have vitiligo.

It should also be noticed that the risk of developing a thyroid condition in patients with vitiligo increases with age. For this reason, it is important that you ask your healthcare provider to always check your thyroid status through lab work and imaging.

You can also practice healthy lifestyle measures to support healthy thyroid function. This includes making sure you don't intake excess iodine through food or skincare.

As we know, stress, both physical and emotional, can exacerbate autoimmune conditions so finding ways to manage stress can help prevent the onset of certain autoimmune conditions.

Reducing environmental toxins can also help lower your toxic burden, thus lowering your chances of developing autoimmune conditions.