Hello,
Small acne at this age can be due to seborrheic dermatitis, milia, infant acne, atopic dermatitis,etc. I would suggest you take pictures showing affected areas and also send detailed query describing other symptoms like itching, redness,etc
Next Steps
Also mention if baby is suffering from cough and cold often with skin rashes. in other parts of body
Health Tips
All the best. Regards Dr Jeetendra Khatuja (Mumbai)