I am experiencing rash on back, under breast and under armpit along bra line, worst under the hook of my bra. they are like big very itchy red bumps?

Contact allergy: You may be allergic to something in your bra and the metal in the bra hook. You may try a different make of bra and one with a plastic hook. Wash the bra thoroughly before use. See that your bra is not too tight. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex, if you have sex. Get HPV vaccine