My daughter who is 8 now was born with horrible allergies. Immediately to formula and then when she was 7 months and started table foods she was allergic to so much it's ridiculous. She has environmental and food allergies. She has gone into anaphylactic shock several times and we carry an epi pen. If it's environmental and she's got a runny nose etc then get rid of all stuffed animals avoid real animals around her. Use safe and clear detergents avoid all scented Bath products use more natural oatmeal based ones. If you notice symptoms try documenting to find out if there is a pattern. Be quick to give baby a bath because sometimes coming into contact can set it all off. I learned with the foods to let her have stuff in small doses and she has outgrown alot of them. Medication wise she was on zyrtec for several years but honestly it made her so drugged up or just plain out didn't work. The biggest things that helped was finding out triggers and avoiding then introducing in small doses and we rarely have any flare ups or anything anymore. Med free now for the last few years and just use benadryl in emergency situations and sometimes she requires having a steroid to clear it up. Don't hesitate to go to the doc and demand to see an allergist they are very helpful in teaching you ways. Also if she is having issues with allergies now avoid table foods until around 1. It's all related and the earlier you introduce the higher likelihood of them developing food allergies also.

Run a hot shower and have her sit in the bathroom with you

Oh! Well you can try the Vicks baby rub, and Vicks humidifier

Unfortunately as far as natural home remedies just a humidifier, there's a natural Vicks salve (I don't remember the exact name of it), sucking her nose via bulb or Nose frida. If she was over a year old, honey, but she's only 4mo, so she can't have honey yet.

@cookiemonster1216, @valerie_jean I should've been more specific sorry I wanted a natural home remedy. But thanks

Always talk to your child's doctor before giving them something.

Talk to her pediatrician. My doc told me baby Claritin, but I don't remember when I started that, so she may be too young for baby claritin still.