Hi mama! Oo, common yan sa 4-month-old babies, don't worry! White spots kaya usually milia (tiny bumps, usually sa nose, cheeks, or forehead) or baby acne lang, both harmless and lalabas na on their own. A few of us also noticed na pityriasis alba (light patches na mas visible sa darker skin) ay super normal din, especially if medyo dry lang ang baby's skin. Pero syempre, best to double-check with your pedia para sure kung alin exactly at baka may specific skin care needed na advised nila. Laging better safe than sorry with baby's skin!