Folliculitis decalvans (probably). Just my story.
I haven't been on here for long but have been really interested to read people's stories. Massive empathy with everyone who is going through whatever variety of this condition you have as I know the stress it can cause. I thought I would share my situation as it is helpful for me to put it down in writing, and also to say how I have attempted to manage my condition.
Around ten years ago I first noticed itching and dryness on the top of my scalp, it was very sporadic and felt just like having a dry scalp, so it wasn't something I took particularly seriously. I had moved to an area with very hard water (water with a higher mineral concentration) from an area of very soft water (low mineral concentration). I had also started working a more stressful job for the first time. My habits in terms of immediately showering after exercise and washing towels/pillowcases were really poor, which, in hindsight was asking for trouble. I think also the fact that I couldn't see this part of my head when looking in the mirror meant that it was 'out of sight, out of mind'.
Over time the itching began getting worse to the point that there was a crusty layer of skin on top of this area and I regularly picked at it, often pulling out several hairs at a time. This provided temporary relief, and my assumption was that the hair would grow back. And that the crusts wouldn't keep coming back if I removed them properly. Obviously this was incorrect - the worst way to try to manage the condition. It led to occasions when I was on trips and I would wake up with dots of blood on my pillow which had come from small open sores my scalp - not ideal when you have to pay for replacement pillows for AirBnb hosts and hotels.
I tried Moogoo scalp cream which helped with the itching overnight. By this point I had also been to my doctor and was prescribed Nizoral ketoconazole shampoo, which also provided some temporary relief. Tar shampoo also seems to help lessen symptoms temporarily.
Usually in the sweaty summer months the condition worsens, or when I have heating on in the house during winter. I think I have a denser hair profile than average which means that sweat is trapped against the skin for longer, providing good conditions for bacteria to thrive.
As I became aware I was losing more hair, my scalp was scarring in the areas where the hair had been lost, and suffering from regular itchiness, I went to see a dermatologist in London last year. I was prescribed with lymecycline, a tetracycline antibiotic which treats acne. This helped with the inflammation I was suffering from, but did not provide a permanent solution. At that point it seemed clear from my research that I have folliculitis decalvans, though I appreciate it is often hard to provide an exact diagnosis.
As my symptoms had largely failed to clear, the dermatologist put me on isotretinoin (accutane) - I have been taking 20mg a day for around six months, and this is where I am currently. I have had some of the common side effects - dry skin and lips, increased sun sensitivity. I have noticed increased hair loss and slight expansion of the main scarred area, and the itchiness is still an issue. This doesn't give me much hope that isotretinoin will work for me, but I will see if a higher dose or different antibiotics may make a difference.
I have also recently started washing my hair with mineral water with low calcium / magnesium mineral counts (softer water), which does seem to help a bit with itching. There is some research out there which shows how hard water can cause scalp issues, and you can usually find reports from your local water company which show if you are in a hard or soft water area. The water's pH is also relevant apparently.
Overall I'm pretty frustrated but aware that others have it worse than me. I will keep trying with dermatologists - it is expensive as I am in the UK and paying rather than using the NHS, but I am fortunate to have access to some good specialists due to living in London.
Thanks for reading and best of luck!