I would suggest that you go to see your primary care doctor
or a dermatologist
about these symptoms. Skin findings are really difficult to interpret over the internet, but with a quick physical examination it is likely that your doctor can tell you what is going on.
Darier's disease is a very rare skin condition that is inherited. Therefore, most people with Darier's disease have family members with the condition. The rash with Darier's disease is very pronounced, dark, and typically located on the chest, back, hands, and forehead. The rash often has a strong odor as well. In other words, it seems unlikely based on the location and description of your rash that you are dealing with Darier's disease.
One condition that is very common on the back of the arms is something called keratosis pilaris, which is a benign condition in which pores become clogged with excess keratin, leading to multiple white or red bumps. Also, it is possible that you actually do have multiple warts
on your skin, which are caused by a viral infection of the skin.
Start by making an appointment with your dermatologist at your earliest convenience, and good luck!