I have seborrhoeic eczema on my face and scalp. I can keep it at bay on my face through using the right oils (let me know if you want my recipes), but the scalp is being more stubborn. It's fungal, apparently, and I've heard that you can't cure it, only manage it. The dermatologist prescribed an oral treatment (didn't work at all) and Nizoral antifungal shampoo (worked, but only temporarily, and it's not a product I want to keep on using). I've messed around with various essential oils and such (no difference) and cassia (didn't help, plus it makes my hair dry).

I also did a "dead henna" treatment a few weeks ago, which contained 116g henna (boiled with chamomile/liquorice herbal infusion for an hour to kill the dye - I didn't know at this point that the lawsone is also what imparts the conditioning properties), 22g amla, 20g rosemary powder, 30ml coconut oil, appropriate essential oils, and lots of conditioner. My hair was lovely afterwards, but it didn't do anything for my scalp, and from what I've read somewhere, the effect on my hair will only be temporary.

So I'm planning to use henna, which has an excellent reputation for treating dandruff and as a general antifungal. I hennaed to a red/auburn for a couple of years when I was twenty, and my hair and scalp were in fabulous condition. I messed around a bit with the odd henna gloss last year, so my ends are a bit coppery and I have about 4" of roots. My natural colour is medium brown, with fairer bits at the temples (the base is more of a golden brown than an ashy brown) that used to get quite bright when I was hennaing ten years ago. I don't want to go red this time, I'd rather stay with copper if I can. This is the current plan:

1. Strand test! This is the useful part about having just had a 4" haircut, though I've freaked several people out by saving the clippings. The tricky bit will be that I'll be testing over henna-glossed hair rather than virgin hair, plus ends tend to be a bit lighter and more porous than roots. Any helpful suggestions here?

2. Henna my roots. I did a trial run for root applications with cassia the other week, which I reckon covered about 2" of my roots and wasn't too hard to do, but for this one I might get someone to help, as I don't have eyes in the back of my head. The idea is to get a decent scalp treatment and also get my roots to match my ends. I'm guessing that an hour or two would probably do the trick, at least to match the colour. I used to use 500g henna for hip-length hair, so would 100g be about right for 4"? 80g? I used 40-50g cassia when I did that 2" root application last week and had a bit left over.

3. If that doesn't deal with the scalp, perhaps try another treatment (if anyone knows of any), and failing that, do a full head henna and hope that I can sort out my scalp without turning thoroughly red.

4. Once I've worked out how many hours I need in total to get my scalp behaving itself, do root applications every few months.

5. Plus the occasional henna gloss or something to keep the ends in good condition.

How does this sound? Any suggestions about other ways of tackling my problem scalp? Are there any good herbs that can be obtained in powdered form, that will also help my scalp and will dilute the henna without making the colour any darker? I currently have powdered rosemary and brahmi sitting around. Should I assume that if cassia alone makes my hair dry, having a bit of cassia in the henna blend won't do me any favours either?

I'm also a bit stuck for suppliers. I'm in the UK, and used to use Ganesha henna from the local hippie shop, but apparently it's now been discontinued. I'm chasing up a couple of boxes on eBay (total 160g), which won't last me all that long. Everyone recommends Renaissance Henna, but she's pretty pricey. Henna Boy is cheaper, but I hear there are problems with reliability there. I'm thinking of using Baldwins, as they seem to have a good reputation as a herbalist supplier and their cassia seemed good (well, it was very finely and applied nicely to my hair, but since my hair doesn't appear to like cassia it's hard for me to tell). Will any decent quality henna do, or is it worth hunting down a particular variety? I hear that hennas from different countries may produce a stronger or weaker red, is that worth investigating, and if so, which hennas should I use/avoid?

Is it likely to make a difference if I break the henna applications down so that they're more frequent? For instance, let's say one 3 hour application vs two 1 1/2 hour applications. Would one of those be better for the scalp, and is it like that one would produce a stronger colour than the other? If I'm better off splitting the applications, how far apart is optimal?

Anyone who's had experience with treating this condition, and in particular treating it with henna: I would love to hear from you!