Can baby acne spread to ears eyelids and head? can erythema toxicum neonatum occur at 3-4 weeks and spread to those places as well? red bumps and pus

Rash in newborn: ETN is not likely the cause (usually in first few days to 2 wks). Neonatal acne is common and generally starts around 3 weeks of age. Yes, neonatal acne can cover the areas mentioned. Another common rash to be considered is seborrheic dermatitis - this rash will typically have flaky patches as well. No treatment for acne, severe seborrhea may be tx with low dose steroid (ask your pediatrician)

Possibly: Acne can possibly go to those places, but can be other things such as eczema, seborrhea dermatitis, heat rash, allergy etc. Erythema toxicum should be cleared by now.