Hello.
Skin conditions such as dermatitis is normally caused by a underlying systemic problem such as inflammation in the gut. This is quite common, inflammation in the body can manifest on the skin in many forms such as dermatitis, eczema, acne, rosacea etc. Applying something directly to your scalp, such as a steroid, will help with the superficial inflammation or reaction but it will not prevent it long term.
I would suggest that you take probiotics daily to ensure a healthy gut, this will reduce internal inflammation. Please visit https://www.healthrenewal.co.za to get more information on systemic inflammation. As well as https://www.healthrenewal.co.za/metagenics to get more info on our range of probiotics.