Welcome and thanks for posting your query to Healthcare Magic.
As per your query you have little rash
that feels like ingrown hairs, sensitive to touch and is on left side of body.
You have not mentioned your age and the exact time period since the rash is present.
Even then we can make out the best possibility of "Herpes
zoster". Thsi is a type of viral infection which is present on one side of body only. The initial symptoms are slight to moderate pain and then there are small blisters which becomes very painful.
I request you to visits your family physician at the earliest to check for the possibility of herpes zoster.
Do not scratch or even try to touch the area unnecessarily. Due to touching or scratching or pinching the area, there can be secondary infection to the area and can aggravate the problem.
In between you can take any good pain killer to reduce the intensity of pain.
Hope these information will help. If you have further queries I will be happy to help.
"With good health wishes"
Dr Sanjay Kumar Kanodia
MD (Dermatology & STDs)