What is the cause of my alopecia?
What could have possibly caused my alopecia areata?
I’ve selected this question below for this week’s question of the week. It allows us to discuss what causes alopecia areata and the relationship between genetics and the environment.
Here is the question….
QUESTION
What could be the likely cause for my alopecia areata if the following conditions are true:
1) I realized that I had insufficient vitamin D
2) I have been experiencing too much stress for the last 5 years resulting in poor sleep
3) I suffered from chickenpox when I was about 8 years old
How do I know if one of the above is the likely cause of alopecia areata?
ANSWER
Thanks for this question. Let’s get right to it and we’ll see that these three things you mention (stress, infections and vitamin D) might have contributed a very small amount but the chance for you to develop alopecia areata was present even on the day your were born. That’s the key message here - you were actually born with the chance to develop alopecia areata.
Alopecia areata is an autoimmune condition. There is a good amount that we still don’t understand but there is a vast amount now that we do understand in the present day and our knowledge is growing constantly. We know that fundamentally the condition is caused by inflammation that accumulates around the hairs that are trying to grow deep under the scalp. The condition is therefore an autoimmune condition meaning that the person’s immune system has become activated in such a way that the immune system generates inflammation around hairs.
In order for a person to develop alopecia areata someday, most probably need be born with the correct set of genes. Some people have the correct genes and some don’t. We know now that this is not just one gene but many genes. As I wrote about back in 2011, there are actually eight genes that really increase a person’s chance of developing alopecia areata and then other genes that might influence it a a bit too.
READ: The Eight Genes that Markedly Affect A Person’s Risk of Alopecia Areata
We now know that most of a person’s chance to develop alopecia areata comes from their genes. Some people have these various genes and are at risk to develop alopecia later in life. Some people don’t have these genes.
In other words, it’s possible to predict to some degree if a person will develop alopecia areata from the day they are born. We may have been able to predict on the day you were born that you were at higher chance to develop it later in life. That said, we don’t test the genetics of newborn babies for their risk of alopecia areata. But we do test newborn babies for the risk of many diseases within the first hours of life. In fact, some counties test babies for their risk of dozens of health conditions by evaluating the genetics of the baby.
But someday it will be possible for parents to ask - what’s my baby’s chance of developing alopecia areata? Someday, after evaluating the baby’s genetics, we would be able to reply back to the new parents “the risk of your baby developing alopecia areata in their lifetime is very low, or we might say that the risk is medium or high or very high.” This kind of information is not routinely part of our world yet. The expense is still enormous to implement this sort of testing and we still don’t understand everything about the disease yet.
But my point is this - the risk to develop alopecia areata is in a person from the day they were born. That doesn’t necessarily mean a person with alopecia must have a family history of alopecia areata. Not at all. But there are genes that have been passed down from parents and grandparents and great grandparents that are present in the patient to give them the increased risk.
Genetics vs Environment: Genetics is important but not enough.
Now that we have reviewed the importance of a person’s genetics, we can move on to discuss what we refer to as a person’s “environment.“ By using the term environment, we are referring to all the things that happen in their life after they are born. This includes the stress the experience, the food they eat, how much sunshine they get, what types of infections they get.
Are these sorts of things relevant to alopecia areata? Yes, they are! But not nearly as much as the person’s genetics.
Both genetic and environmental factors have a role in alopecia areata - but genetic factors have the biggest and most important role
The sorts of things a person is exposed to can “tip” them from being a person who is unlikely to develop alopecia areata at any time in their life to a person is actually develops it. In this case, we would say that the person’s environment had a major effect on their alopecia areata. Similarly, a person’s environment can also tip them from being the sort of person that has a high chance to develop alopecia areata to a person who never every develops it. Those factors of course need to all be worked out completely but that’s how we have come to understand this disease.
This pie chart above is a helpful reminder to us all that when it comes to alopecia areata the genetic factors are much more important than the environmental ones - but everything has a role.
A Helpful Model of Alopecia Areata
So when I think of alopecia areata, I think in terms of the diagram you’ll see below. Hair follicles respond to signals that tell them to grow and signals that tell them to fall. For most people the “grow” signals are what predominate - and so that’s what hair follicles do. Even for people who are born with the chance to develop alopecia areata - most of what is heard by the hair follicle are the grow signals. Day in and day out the grow signals are what is heard. Not surprisingly, even if a person has the right genetics to develop alopecia areata - most won’t develop it any time soon because the grow signals far outweigh the fall signals. There might be few voices whispering “fall, fall fall” but there is a massive choir singing “grow, grow, grow” - and so the hair decides to grow.
Environmental factors like stress, infections, and some medications and low vitamin D like you said have the potential to tip the balance in some people and lead to the hair follicle receiving more fall signals. This probably only happens in people that have the underlying genetics to develop the condition in the first place. If the underlying genetics is not present in the person at birth, these sorts of environmental factors usually don’t cause alopecia areata.
Summary
I thank you again for your question. Your stress, low vitamin D and poor sleep and the infections you had in the past are your ‘environmental triggers.” They do have some role and in the present day and age we can’t tell you exactly how much of a role they had. But they had some role. The main message I hope that you will receive from this article is that your genetics is the main factor that influenced your alopecia. It’s a pretty complex genetics and most people don’t have strong family history of alopecia. But in your family there are probably other autoimmune diseases in parent, grandparents, great grandparents, great great grandparents or great great great grandparents that have influence the complex set of genes that you were born with. Some of these genes when they come together have influenced your risk to develop alopecia areata. All the various environmental factors come together to influence whether there are really enough “fall signals” present or not to cause thee hair to fall out.