Eczema in the middle of the two breasts may be allergy, or contact dermatitis. 1. Allergy: patients with a lot of sweat, the front of the chest and was smothered for a long time, failed to dry the skin in time, the skin barrier is easy to damage, contact with a variety of external factors such as dust, easy to induce eczema. 2. Contact dermatitis: Wearing underwear made of non-breathable materials or dyed with irritating chemical dyes, or contact with metal parts on clothing or jewelry may lead to contact dermatitis. If you have eczema in the middle of your breasts, it is recommended that you wear breathable clothing, keep your skin dry, and go to a dermatologist as soon as possible.