Monday, 2 April 2012

Scalp matters: Understanding dandruff and scalp eczema

This is a post that I wrote for BGLH but it is quite relevant for those of you suffering from scalp issues so here goes!


Quite often people mix up dandruff and scalp eczema. The truth is both of these conditions are very similar and they both actually share the same cause but knowing the difference between the two can greatly help to get the correct treatment and management.

What is dandruff?
Dandruff is characterised by loose skin flakes which are normally white in colour. There is also usually some itching but this is usually not very severe.

What is eczema?
Scalp eczema,like dandruff  is also characterised by  flaking and itching. The big difference is that scalp eczema often results in greasy, yellowish flakes and the itching can be quite severe and accompanied with inflammation (meaning skin feels hot and is swollen). Additionally if you have eczema elsewhere (under the nose, on the hands/legs etc) the likelihood is that what you may perceive as dandruff on your head may actually be eczema.

What causes dandruff and seborrheic dermatitis?
Dandruff and eczema have a similar cause and three main things create the right environment:

1. Fungus: Our skin and infact our bodies are covered in bacteria and fungi both inside and out. This is perfectly normal and should not be any cause for alarm. The reason why the scalp begins to flake is that a normal fungus that is found on the skin is produced in higher amounts than normal. This fungus is known as Malassezia and it affects the scalp because its food source is a specific fat found in sebum.

2. Sebum: The fungus Malassezia uniquely prefers one specific fat in sebum known as oleic acid.  By specifically choosing to consume this fat above all others in sebum, the composition of sebum is altered . This alteration is then thought to lead to the cells on the scalp losing their adhesiveness and flaking off.  

3. Individual susceptibility. The fact is that some people have dandruff and some do not. Some people have eczema and others do not. For some people high levels of the fungus -Malassezia or indeed of its food source - oleic acid, does not result in dandruff. However, for others, even slight changes in the balance leads to problems.

Myths
Dandruff and scalp eczema are not linked to washing hair frequently or infrequently. Having dandruff or scalp eczema does not mean that your personal hygiene is low.

References
1. J Investig Dermatol Symp Proc pp 15–19, (2007)
2. J Investig Dermatol Symp Proc 10:194–7 (2005)
3.  Science 304:304–7 (2004)




11 comments:

  1. I have had eczema on my scalp and face ever since I was a child. It takes some time to get to know what works for you an what doesn't. Once you figure that out, it's not so hard to deal with.

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  2. I've had seborrheic dermatitis/scalp eczema (never heard those terms used interchangeably) since I was a teenager as well. It goes and comes over the course of the year and I've yet to find a sure fire method to keep it completely at bay. I have learned to treat it as soon as possible to keep it from proliferating and that the change in seasons affects me the most. Its a really annoying issue, but I suppose it could be worse.

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    1. You know the terms keep changing depending on which medical text you reference. Seborrheic dermatitis is also referred to as seborrheic eczema and also even psoriasis. Eczema is referred to as atopic dermatitis and seborrheic eczema. I think the set of symptoms for all are quite similar though.

      Eczema is one of those conditions that you have to manage. It has a tendency to flare up.

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  3. This post came just in time! I have eczema that has seemed to subside over the years. In cases of extreme temperatures (really really hot or cold) it flares up again and that's when my scalp seems to go crazy. I wash my hair about twice a week in extreme weather, once or less per week when everything is fine. I really don't know what works other then rinsing my scalp when it's irritated. Rinsing with Apple Cider Vinegar works but not always. It seems something I'm just going to have to deal with.

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  4. Oh ok! I didn't know what was going on with my scalp. I have eczema on my feet and it has been flaring up recently along with my scalp.

    So how do I go about treating my scalp? I tried using diluted ACV on my scalp a few days ago and it seemed to be alright but I still have flakes today. Would Head and Shoulders work?

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  5. Thanks for this post! I have a spot on my scalp that itches like mad, and of course I scratch or at least rub so it's also sensitive as a result. It's been this way for at least a year now. It sometimes starts to itch soon after washing (with shampoo) so I don't think it's due to product build up. I have also used different products during the year, in search of the perfect combo. I thought it was eczema (self diagnosis) but there's no flaking. I'm baffled! Any ideas on what the culprit could be?

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  6. I have this condition and once a month treatments of henna and honey mixture keeps it at bay for 3-4 weeks and my scalp clean. I actually do the treatment when I start to see build-up. Working out and sweat ( I am a heavy sweat-er) irritates my scalp and can lead to early build-up and extreme itchiness if I don't rinse at least twice a week during a really active week, but just plain water and moisturizer after keeps my scalp clean until the next henna. I was really impressed with this side effect of henna and haven't experience any of the other side effects listed in your article. hth

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    1. henna is really good . actually better than apple cider vinegar and shampooing. it also helps reduce hair fall and makes my hair more manageable.

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  7. I am in a situation similar to Dee Rose; My scalp is very very itchy, but it does not flake at all.

    Somehow, my scalp seems to be the most itchy at the crown, and when the hair is damp, or dry, or has coconut oil in it. Since my mother accused me of using too much water in a day, I started moisturizing my hair daily with my leave-in rather than with water, and my hair was much more hydrated. However, the itch remained. Through all the additions to my regimen that made my hair thrive (henna, aloe vera juice, castor oil, removal of coconut oil, addition of essential oils to my scalp/sealing oil, protein deep conditioners, and better moisturizing deep conditioners), my scalp remains itchy, and I actually experience hair loss because of the friction and torsion I put on my hair by scratching my scalp (which it why I added henna and protein to my regimen, and eventually got my hair cut very short to remove the dammaged ends).

    I don't know what to do any more. My dermatologist said there was nothing wrong with my scalp at a pathologic level, but that it was likely that I just had a bad case of trichorrhexis nodosa. But knowing that my hair was breaking close to my scalp doesn't tell me what to do about the itch that causes it to break.

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    1. I have that same problem in the middle of my hair and it seems to grow slower than the rest of my hair! I will try the henna treatment! My dermatologist was no help said I had a mole in my hair or something! Have you had any improvement?

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