Hi,
From the way you explain there may be so many etiologies for your problem, and the treatment is almost same except specific treatment. I suspect that you have Contact Dermatitis
Contact dermatitis is a
rash on the skin that can be itchy, painful, or tender. Sometimes it can cause blisters or swelling. Contact dermatitis is caused either by a substance that irritates the skin, or a substance that causes an
allergy on the skin. Some substances that can cause contact dermatitis include soaps, perfumes, poison rubber products, cosmetics, jewelry, and medications.
You usually can avoid further contact dermatitis by avoiding the substance that causes it, provided you are able to find the cause
Most contact dermatitis is treated with corticosteroid skin creams or other skin creams or
ointments. If the rash is severe, your doctor may suggest oral medications. Applying wet, cool compresses to the area or taking a cool bath can also help ease symptoms.
Scratching the rash, rough clothing, and continued contact with the irritant or allergen can make the rash worse.
Get the correct etiology (including diet) and treat accordingly. You will be alright.
I wish you a speedy recovery
Best wishes