Keeping good scalp hygiene is the first and safest patch up you can take to treat this condition. Get an anti dandruff shampoo, or one manufactured for oily hair and use it along with an adequate conditioner. There are shampoos containing tea tree oil, lavender oil, or zinc which help decrease oil production of the scalp as well as cleanse your skin and hair without over drying them.
You may also keep in mind hair products recommended to treat seborrhea or use astringents moderately to prevent over drying your scalp, otherwise your pimples on scalp will go on. Another good patch up is to drink a lot of water. Water keeps your skin healthy and it helps to cause less oil.
If your scalp acne is mild, you can also treat it with medicaments used for acne on the face and body. Some satisfactory over-the-counter products are those containing salicylic acid. Apply these products exclusively on affected areas using a Q-tip as they can create too much dryness.
Keep away from any product that contains benzoyl peroxide, specifically if you have chemically textured or color-treated hair. The peroxide, when it comes into contact with your hair, can change its color and give you an awful look. Treating pimples on scalp can be problematic if you have other scalp headaches such as dandruff and a very oily scalp.
If your acne doesn't clear with any of these pointers, or if you have a more extreme form of scalp acne or your condition becomes too painful and uncomfortable, you should call in a doctor or a dermatologist.