Hello,
Without examination,confirmation of a diagnosis is tough,but it can be hives,sweat urticaris or contact dermatitis.
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.
The mainstay of treatment of hives is antihistamine which may be necessary for prolonged periods (in excess of 6 weeks).Non-sedating antihistamines such as Cetirizine and Loratadine(Claritin) may be needed to get symptom relief. Sedating antihistamines such as Chlorphenamine(benadryl)are used at night to get urticaria control. Short courses of oral cortisone or steroids are taken for short periods (one to three days) to settle more severe symptoms.
You may take Vitamin C along with the prescribed treatment. Vitamin C is a general anti-allergy supplement. Pls do not use any cosmetic product,maintain a good hygiene and apply calamine lotion on this rash.It will help in soothing the skin.Wear cotton and free flowing clothes and try keeping cool as urticaria may tend to flare up in warmer conditions. In particular, keep the bedroom cool at night.
If the symptoms persist then pls get it evaluated from a dermatologist.
Hope it helps.Take care and pls do keep me posted if you have any additional queries.
I also have victoria's secret bras, but the hives started on my neck so that couldn't be it could it???