OK I'm back...doesn't seem to be an edit button to amend my other post so I'll start again!
Where to start...I first lost my hair 2 years ago, and within a fortnight I'd lost 80% of it. Shaved the rest off and my gorgeous husband bought me a wig.
My then-7-year-old had also suffered from alopecia in the months before I lost my hair, and I discovered various odd facts. One being that alopecia occurs in a small % of the population, BUT if a blood relative has it then the chances of another member of the family sufferring too shoots up into the 90%'s.
Once you've had alopecia the chances of recurrence are high. The more times you haveit the less likely it is that your hair will grow back.
That's the bad news...
BUT this is the third time for me. The first time like I say I lost 80%...6 months later I had very short hair and was able to be photo'd for my passport without my wig.
The second time, just a 50p soze patch right on top of my head (that seems to be my weak spot, where it always starts), I managed that by rejigging my parting and clipping down a bit of a comb-over.
This time...a large area again right on top of my head and fringe...my wonderful hairdresser has managed to show me ways of virtually glueing down the rest of my hair and we can just...only just...cover it up with serum, hairspray and hairbands/clips. I still have my hats and wig.
Scientific facts...
No matter what you use on the outside of your head, it will not cause alopecia. Alopecia is from the roots of the hair not the surface.
Obviously hair can be damaged on the outside by whatever you put on it and may break on the surface, but that is a different thing to actual alopecia.
WRT your son, if he/you are able to pay and he doesn't want anyone "knowing" then get him an appointment with someone privately, a trichologist who can do some scalp scrapings etc. Whatever he has researched on the internet may well be useless...we all have heard of the magic slimming cures etc that you can buy that don't work.
Mentally, I felt so much better the first time once ALL the hair that was left had been shaved off. A real confidence boost because it meant I could wear hats and my wig without worrying that a bit of hair would be visible with a big bald patch behind it. I felt LESS bald once it had all gone.
My husband lost his hair at 18 due to a family history of exczema (I can't spell that sorry!), and he too shaves off what does grow as he then feels bald by choice...and looks bloody sexy too!
Ask me anything you can think of and I will answer if I can help...sorry this is long and it may not help but please try and reassure him he is not alone