Are there other symptoms present? It is good that you had this tested already. If there is no personal history of allergies, this could be an irritation to substances such as detergent, soap or from jewelries. Try to avoid putting any of these on your hands and try to reintroduce each one to determine which substance could be causing this. Keep the area clean and dry/ And avoid manipulating the lesion ot prevent secondary infection.
Take care and keep us posted.
I cannot confirm anything without examination but from the recuurence of symptoms,it sounds more like hives or urticaria. Hives (medically known as urticaria) are red, itchy, raised areas of skin that appear in varying shapes and sizes. They have a tendency to change size rapidly and to move around, disappearing in one place and reappearing in other places, often in a matter of hours.
Many cases of hives are "idiopathic," meaning no cause is known. Others may be triggered by viral infections or medications.Take some antihistaminics like benadryl or Claritin and apply some calamine lotion on the rash.You can also apply some mild steroid cream on the rash.If the symptoms persist then oral steroids may be needed.Pls consult a dermatologist in that case.Also eczema has to be ruled out then.
Hope it helps.Take care and pls do keep us posted if you have any additional queries