It is always a good idea to see your doctor
when you are not sure of what is going on. Rashes or bumps on the skin can be caused by many different things, and it can be difficult to figure this out over the internet. However, your doctor should be able to tell quickly after taking a look.
There are several likely possibilities. The first is that you have eczema
. This is a condition in which the skin becomes dry, irritated, and itchy, either due to lack of moisture or due to exposure to some irritating or allergy-provoking chemical (such as a new laundry detergent). You may want to try moisturizing the area and applying an over the counter anti itch cream to see if that makes a difference.
Another possibility is folliculitis, which is an infection of the hair shafts, resulting in small red bumps at the base of several hairs. This causes rounder, smaller, more raised bumps than eczema, and it is mostly treated with good skin hygiene and topical antibacterial cream.
If these two approaches don't work, then you should definitely seek help from your doctor. You should also see your doctor immediately if the symptoms worse or persist.