Last Updated on 1st June 2020 by Caroline Haye
More pigment instead of less
Some people call them beauty spots or beauty marks. Others call them moles. Some of us love them and others think they are unsightly. Most of us have them somewhere on our body. And the majority of us probably don’t pay them much attention. But what exactly are they? And are moles linked to vitiligo?
This may seem like an obscure question to ask. But I quite like looking for answers to obscure questions because a lot of what I find is fascinating. If you are the same, then read on. But, if you prefer to cut to the chase, just scroll down to my Roundup of this subject towards the end of this post.
What are moles?
Unlike freckles, which are usually lighter and often only appear for a period of time after sun exposure, moles are darker in colour and are more often permanent. These dark, often raised, spots vary in size and range from black to light brown in colour. They consist of a dense cluster of pigment produced by an overgrowth of melanocytes. So, in a way, they are the very opposite of vitiligo. They are spots that have more pigment than the surrounding skin, instead of less. Both moles and vitiligo are lesions of contrasting colour. But whereas moles are common to most people, vitiligo is not.
What causes moles?
Since a mole is a cluster of pigment producing cells, it is not surprising to learn that they appear predominantly on those parts of the body that are exposed to the sun. And the fact that these melanocytes huddle together, instead of spreading out, accounts for their dark colour. But what I wondered was what makes them huddle. Unfortunately, I couldn’t find much information on the physiology of why this happens. Whereas scientists have studied abnormal cell growth in skin cancers in depth, very little research exists into what causes normal moles in the first place… Probably because the majority of them are benign. What is likely, though, is that genetics play an important part in how likely we are to have moles and how many we have.
Are moles good, bad or ugly?
Whether you consider having moles on your skin to be a good thing or not, the fact is that it is very common and not usually a cause for concern. In fact, most of us have somewhere between 10 and 40 of them by the time we reach adulthood.
But it is, of course, important to keep an eye on any changes in their size, texture or appearance because these can be a sign of cancerous activity. (There are many guides online that can help you to identify these signs.) However, most of these marks are harmless and not all changes are an indication that something is wrong. These moles can grow, change colour or even disappear for no apparent reason.
As to the question of whether they are ugly or not, that is definitely in the eye of the beholder. To some extent, the visual effect of a mole depends on whereabouts it is. Mine are in random locations on my body, mainly on my arms and back and I quite like them. If I had a mole on my face like the model pictured at the top of this blog, I’d probably love it. But, if I had one on the very tip of my nose, that might be a different matter.
Some people feel much the same way about their vitiligo. A small white patch of skin might be insignificant, or even a novelty, whereas larger, more prominent areas can cause distress, embarrassment or total loss of confidence in one’s appearance.
Celebrity moles
For certain celebrities, a mole can be a trademark. In fact, some people even apply false ones or darken existing ones with make-up. But others opt instead to get rid of them.
Marilyn Monroe is said to have enhanced hers with an eyebrow pencil. And it’s hard to say names like Angelina Jolie, Cindy Crawford, Morgan Freeman, George Hamilton and Robert De Niro without visualising their characteristic “beauty marks”. Enrique Iglesias and Sarah Jessica Parker, on the other hand, must not have liked theirs because they had them removed.
Is there a link between moles and vitiligo?
So, on to the original point of this blog: is there any link between moles and vitiligo? Well, I couldn’t find any suggestion that one condition either causes or prevents the other. But I did find some interesting similarities and associations between the two types of skin lesion. And I have summarised these below.
Genetic effect
Similar numbers of moles tend to occur within families, which suggests that there is a genetic dimension at play. But, just as with vitiligo, scientists don’t yet have a complete picture of “mole genes” or how they pass from one generation to another.
One survey, in the Journal of Investigative Dermatology, reported that moles on the upper portions of the body (among white women at least) were associated with a 37% higher likelihood of vitiligo. If I understand this study correctly, this does not mean that having moles on your upper extremities leads to vitiligo. It just means that it may help flag up who is more likely to develop it.
Hormonal effect
As with the onset of vitiligo, it is common for moles to appear at times of hormonal change, such as puberty, pregnancy and menopause. This is not surprising when you consider the crucial role our hormones play in the regulation of our pigment production.
A common symptom during pregnancy (and menopause) is melasma, the appearance of darker patches of skin. And many women also notice their moles becoming darker too.
Conversely, vitiligo sometimes improves during pregnancy and becomes worse again after childbirth, again indicating that changing levels of hormones affect both skin phenomena.
Autoimmunity, oxidative stress, and the Koebner effect
Autoimmunity is a key part of the vitiligo process. And, it turns out that it is also involved in a particular kind of mole, known as halo naevus (plural: naevi and US spelling: nevi). This is a mole with a ring of white skin surrounding it. An earlier name for this fairly common phenomenon was leukoderma acquisitum centrifugum… A term which hints at its visual similarity to vitiligo. And, like vitiligo, it is the result of an autoimmune attack on melanocytes… In this case, are those in the mole. The de-pigmentation caused is not usually permanent, whereas vitiligo, more often than not, is.
Not only does research show that the development of vitiligo and halo naevus both involve an autoimmune response, but it also shows similar raised levels of oxidative stress in both conditions.
Friction or injury to the skin can cause de-pigmentation in affected areas and this is also true of halo naevus. In other words, both conditions are susceptible to “koebnerisation”.
A roundup of the information I found on vitiligo and moles
One of the few research papers I found that focused specifically on the relationship between moles and vitiligo was conducted in 2010 by the Vitiligo Clinic at the Department of Dermatology, University Hospital Center of Bordeaux. This study compared cases of vitiligo (non segmental, or NSV, which is the most common kind) that occur alongside halo naevi versus cases of NSV alone.
The reason given for studying both conditions together was their “striking clinical association.” The authors apparently wanted to put to the test various previously held beliefs. These included the possibility that halo naevi may be either a risk factor for, or else a clinical sign of, vitiligo.
The study suggested an inflammatory/autoimmune origin for both conditions and some interesting comparative data. It found that having halo naevi plus vitiligo affects the age that depigmentation starts, as well as the pattern of pigment loss. And it also showed a stronger link with familial premature hair greying when both conditions are present.
Final thoughts
To summarise what I have learned, my investigations into this subject have unearthed some similarities between vitiligo and at least one type of mole (halo naevus). Both are forms of leucoderma (i.e. de-pigmentation) and both involve autoimmunity and inflammation / oxidative stress, as well as genetic and hormonal factors.
I also found a few studies pointing to other associations between common naevi and vitiligo that scientists do not yet fully understand. There has been very little research into this area specifically. This may be because it does not appear to offer as much potential for developing vitiligo treatments as other areas… And probably also because most moles are not a disease and therefore don’t require a cure.
I hope you have found this topic interesting. If you are as fascinated by the subject of skin pigmentation as I am you might enjoy my mini series of blogs about the weird and wonderful world of skin colour, starting with part 1: How Transparent Are You?
