If the plastic bag is white, titanium dioxide is the white pigment that is often used. She may be allergic to that.
Hi, welcome to the forum, her symptoms are suggestive of irritant dermatitis. It seems secondary to the certain things she is exposed to (plastics, soaps, detergents, garments).
Firstly, she need to get investigated for possibility of allergen by skin allergy testing.
- Identify all the possible allergen and maintain a diary.
- Avoid exposure to allergen like plastics and petroleum jelly.
- Low potency topical glucocorticoids and oral anti histaminic against prescription can be helpful, during the reaction.
I suggest her to consult dermatologist. Take care and regards.