Hi,
This seems to be contact dermatitis from what you describe. Contact dermatitis is a localized rash or
irritation of the
skin caused by contact with a foreign substance. Only the superficial regions of the skin are affected in contact dermatitis.
You need to wash the areas several times with fresh water. Do not use any cosmetic products at the sites.
Apply calamine lotion at the site of the lesions and see if it helps.