My throat has been producing this frothy white sputum and I always spit it off. I don't have productive cough at all. I also experience chest and back pains later of the day. I'm f, 23 years old and a month ago I was diagnosed to have minimal pleural effusion. After a week of antibiotic treatment, my cxr states that it is back to normal. I just don't understand why my backs keeps on aching.