My son has had hard, red bumps, mostly of the same size and
non-crusty, all over his scalp that was very itchy. He has
relatively fine, thin hair. We guessed they may be eczema, but the
bumps he had didn't quite fit the description nor the pictures we
found on the web. My son decided to go to the doctors and shaved his
hair off for the purpose -- within a few hours, the bumps had
disappeared completely.  Now he doesn't have anything to show the
doctor, but he would like his hair back eventually. What are the
bumps, and what could be causing them?

Bumps on your scalp can sometimes be the result of clogged follicles,
particilarly if you have naturally oily hair.

Apparently your son is not a kid.  From your description and from what
I found here and on related other sites, I wonder if this could have
been the problem.

http://www.kidshealth.org/parent/infections/parasitic/lice.html

That's only a guess (based on experience with with our kids).  As
these sites all emphasize, it can happen to anybody.

Years of symptoms disapeared after a week and a half in Japan. (see below)
For a decade or more i've had problems with these sores and flaking
crap on my head while living in Los Angeles.
My skin doctor
prescribed a selinium based medicated shampoo (as none of the store
bought seemed to effect it)
later 'rosia' (or rosia like) symptoms also occurred around the eyes.
The shampoo helps both a bit, but i found that if used more than twice
in a row, other unpleasant symptoms occur.
So I got in the habit of using 3 shampoos and never the same one in a row.
(i have tried changing medicated to "normal" or using different
medicated shampoos-nothing seems
to keep it at bay except constant switching)

My wife also helped by researching/supplying vitamins and minerals.
All these treatments merely kept it at bay as opposed to anything close to a cure. 
BUT.....
A curious result of being in Japan for 3.5 weeks. ALL SYMPTOMS
disappeared after 1.5 weeks!
I don't know if it was the diet(mostly fish and tofu,) the water
(though heavily chlorinated,) the weather
(mucho humidity,) or ?

Also did not take  vitamins/minerals while there.
I was suddenly "cured."

Now I'm back in the U.S. a little more than a week...the symptoms are returning...

Some posts above mention excercise and sweat..while I excercise in
L.A., I don't sweat
much. However in Japan, excercise or not, I sweated alot from the humidity.
Perhaps related?

Dear All, 

Thank you for your comments. My son and I have been observing his
scalp for the past few days -- and noticed the itchy bumps returning
intermittently with no correlation to time of day, degree of humidity,
or any particular food consumed. He does, however, have mild acne, so
it may very well be acne or clogged follicles on his scalp.

I was especially interested to read fred_u's comment, as my family is
exposed to pretty similar environments as what you described: mostly
vegetarian diet with some fish, heavily chlorinated  water, and mucho
east coast humidity. We were visiting relatives in L.A. for a few
weeks, but there was no apparent difference in his condition. 
Mysterious indeed. I will look into the shampoo.

Now that the symptoms are returning, we can make a trip to the
doctor's... hoping the bumps will stay long enough to be looked at.

Thanks again for your inputs!

I am not sure what you may have, but I had a scratchy scalp and sores,
tender spots on my head that when looked at appeared as a red area
around a raised yellow looking pimple at the center of the sore. When
broken they would mildly bleed. What I had was called foliculitis; an
infection of the hair follicule. This infection typically appears on
the scalp, thighs and buttocks. Anyway, three different doctors had me
on anti-biotics and none of them helped; then, while staying at a
Resort and discovering I had no shampoo with me, I decided to just
wash my hair with the soap in the room. It was Dial Antibacterial
Soap; Not plain Dial soap but the bar that states it is Antibacterial.
I used it and my head felt better immediately and after using it for a
couple of weeks I lost all my sores and all the itchyness. I hope this
works for you. By the way. While I was using the soap, I did not
follow it up with a conditioner. I am not sure if adding a conditioner
would interfer with the Antibacterial action I was getting from just
using the soap. If it works for you, please share this information
with others as  I spent hundreds of dollars with Doctors and drugs
with no success. and I would not want others to do the same. Good luck
to you. George

I just searched this site because I have the sores all over my scalp. 
I am thinking it has got to be hormonal, because I used to always get
this condition right before my period.  That doesn't explain why men
have it though. I just can't stop picking at them.  Nobody else that I
know understands this problem.  I feel like a freak.  My hair is
definetely not thin.  It's just as thick and long as can be (too long
right now).  I haven't found a thing that works.  The sores just come
and go.  I don't remember how old I was when it started.  I'm 34 now. 
I didn't get it at all during my two pregnancies.  I didn't get any
pimples on my face at that time either.  If anyone finds a cure,
please let us all know!!!

Oh, I have another comment.  I heard about two acne products that heal
from the inside out.  The first is called Clear Skin Image, by
Coenzyme A Technologies.  They are capsules and you're supposed to
take like 6 a day.  But it worked for a 13 year old girl that I know,
and she was only taking one a day, mixed up in her juice.  But she has
acne on her face....not this scalp condition.  But I think I'm gonna
try it for this.  The other are Zenmed products.  They are all natural
and work well for acne.  I haven't tried either yet.  I'll let you all
know if anything works for me, and I hope you will do the same.