Ay nako, mama, this sounds uncomfortable para sa baby mo, please take him to the doctor or pédiatrician agad, lalo na kung may rashes or signs na uncomfortable siya, para malaman natin kung ano talaga ang nangyari.
In the meantime, keep the area clean and dry lang, at avoid tight clothing doon. A few of us mums found na pag humid ang weather, mas prone ang babies sa irritation sa neck area, kaya bantayan mo rin ang sweat. But the doctor needs to check kasi baka may specific reason kung bakit nkkahi siya, it could be iba't ibang things, at importante malaman exactly ano para ma-address properly. Sending you both love!