Dermatitis is just a medical word that means "inflammation of the skin." The red, itchy bumps that you have everywhere certainly could be evidence of dermatitis. Dermatitis does generally cause itching and the spots are often red, although they may also be scaly, or flaking, or blistered and weeping depending on the cause of the dermatitis.
There are several common causes of dermatitis. One very common cause is contact dermatitis, which occurs when the skin comes into contact with an irritating substance, usually a chemical like a new laundry detergent or soap. If you have recently changed any of your household or personal care products, this is a likely offender.
Another very common form of dermatitis is atopic dermatitis, which occurs in people whose skin has a tendency to dry out. This tends to be more of a chronic condition which however can flare up quite significantly in times of stress.
The best thing to do would be to set up an appointment with your primary care doctor
or a dermatologist
. They will be able to take a look at your skin to help you figure out what is going on. It is likely that you will need a steroid cream to help get this inflammation under control.