My 13 month old son has been coughing hard at nighttime only for about 3 weeks, and yesterday his lips, feet, hands and torso were purplish blue. I took him to acute care, and they said it was acrocyanosis and to just watch him and keep him warmer. He has never had this before, has no history of anything, not even ear infections, although he had a heart murmur and pneumothorax at birth. In the middle of the night, I got up to check on him, and his breathing was very shallow and he seemed to be excessively salivating, almost "foaming at the mouth." Does anyone have any ideas? This isn't sitting well with me, and is scary to see him this way. Thanks!