Hi, the probabilities of the itching with rashes are Atopic dermatitis, Contact dermatitis, sweat dermatitis, seborrheic dermatitis and drug reaction. There seems to be persistent allergic insult by the allergen (detergents, garments, soap etc.)
You need to report if you have taken any suspected drug before this like sulfa drugs. Also any previous history of eczema, asthma, and allergic rhinitis should also be taken in to consideration.
Oral anti-histaminics and corticosteroid against prescription, which may help to alleviate these symptoms. You need to avoid exposure to detergent to prevent further complication. If you want to use it you can wear gloves so that direct contact can be avoided.
I suggest you to consult a dermatologist. Take care and regards.