Scalp irritation, shampoo/surfactant recommendations

Approximately seven years ago I developed eczema on the back of my neck.  About two years ago I switched to a shampoo without SLS and the eczema disappeared (to the touch) within days (and never returned).  Within the last few months I have been getting a rash, itchy, with bumps that feel a bit like acne to the touch, on my scalp.  I have tried many shampoos, all of which provoked the same reaction after more than one use.  The only thing I tried (out of desperation) which caused no reaction was a very diluted solution of baking soda in water, but it was not very friendly to my hair.  After looking on the internet, and seeing that coco betaine is a common cause of dermatitis, and given that every shampoo I have tried has contained coco-betaine, am thinking that it is the most likely culprit.
  
My question is, given my skin's reaction to both sulfates and (presumably) coco-betaine, what surfactants should I look for in shampoos (which are least likely to cause a reaction?) and could you recommend a specific brand/shampoo I should try?  

[dsalkfjj]

Also, I also stopped using any type of detergent/body wash/ soap/etc. on the rest of my body (except my hands) unless absolutely necessary because it made my skin frequently break out in rashes.  Unfortunately, I don't have this option with my hair.

[Bhupinder Kaur, MD]

Hello,
From your symptoms the rash can be due to contact dermatitis but for the bumps, folliculitis and perifolliculitis needs to be ruled out. It is characterized by small, very itchy pustules within the scalp, often most troublesome on the frontal hairline. The scalp should be washed with a mild normal shampoo as often as desired. Antidandruff shampoos containing antifungal agents such as ketoconazole or ciclopirox are sometimes helpful. Apart from that you need topical and oral antibiotics, antihistamines, oral steroids and topical tretinoin.

My sincere advice is to get it examined from a dermatologist. It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.