Croup is technically the inflammation of the larynx/trachea in children, which causes breathing difficulites and is usually associated with infection. The inflammation in the voice box, bronchial passages and windpipe may cause the voice to be raspy and produces a cough that is typically described as "barking."

Croup is generally caused by a virus that is spread by infectious droplets in the air, thus use caution around others who are coughing, practice appropriate hygiene and boost the immune response by paying close attention to diet. For example, avoid sugars that feed infection and lower immune repsonse and increase probiotics such as homemade fermented foods (veggies, kefir, yogurt etc.). 

Coughing/breathing difficulty episodes can be alarming for both the child and parents, but thankfully croup usually responds well to natural remedies. If it is persistent, please consult your trusted health care provider. 

In Robert Tisserand's Essential Oil Safety Masterclass (2022), Robert stated in a Q&A that he personally felt that ingesting eucalyptus capsules was very effective for respiratory issues.

Croup usually responds well to comfort and increased fluids as well as boosting the immune response to the virus. 
Shower Steam: Run hot water in the shower while you hold your child in the room. The steam helps them breathe. Adding a couple drops Eucalyptus oil to the shower (not suitable if the shower stall is plastic) enhances breathing.

Chest Rubs: Dilute suitable oils appropriately for the age of the child, and for the very young (infants/babies), mom can apply the oil to on her neck/chest area so the baby can breathe it while nursing.

Coup Essential Oil Blend by Purchon/Cantele
10 parts Sweet Marjoram
10 parts Thyme ct linalool
2 parts Rose
Diffuse, make a personal inhaler or use as a massage oil when appropriately diluted with a carrier oil for the age of the child.

Testimonials
1. My son, who is now five years old, had meningitis when he was 15 months, and since that time he comes down with bronchitis/RSV-type illness every winter. He was hospitalized when he was two and put into an oxygen tent for five days. He constantly had a terrible cough, phlegm and had trouble breathing. He used a nebulizer a lot. We took him to specialists. They thought at first he might have had Cystic Fibrosis, but he didn't. He would get so sick that he wouldn't eat. Not only was he sick all the time, but he was not growing! The only oils I had at this time were Peppermint and Lavender and a few drops of Plague Defense. Fairly late one evening my son got up and was complaining of an earache. I got out my oils and thought I had the Lavender, put a drop on his chest and then some on his ears, and then I realized that in my sleepy state, I had grabbed the wrong bottle! I had put Plague Defense on him instead of Lavender. I was so worried that his skin would start to burn! I rubbed vegetable oil on him and we were off to bed!

The next morning he woke up and started coughing terribly! It was a croup-like cough, and I thought my mistake by using the Plague Defense instead of Lavender had really hurt my son. I felt sick about it! I later came to feel that the oils were just doing their job getting to the 'bug' before it had time to settle in his little lungs. I decided to reapply the Plague Defense just the way I had the night before. I applied all three of the oils I had, but the cough was still there. His ear didn't hurt any longer, but he was still coughing like the croup. I got some Respiratory Relief and added that to my protocol. By the time he went to bed that night the cough was sounding a whole lot better, and the next day, it was gone!

Since that day, my son has not had one bout of bronchitis, RSV or asthma-type symptoms. I put Plague Defense, Peppermint, Lavender and Respiratory Relief on his feet and chest every night, and he does not get sick anymore!! He complains of an earache maybe one or two times during the year, but a drop of Lavender on a cotton ball in his ear is all it takes, and in hours his earache is gone!! How wonderful it was to throw out the nebulizer and antibiotics! He is still small for his age, but he is growing now and eating like a horse!! He's a little guy, but he doesn't have to struggle any more to breathe. He can play in the snow, and we don't worry about him catching cold. Our lives have been changed so profoundly, and I could never express my gratitude in words! These oils ore awesome! We are truly blessed!

2. My six-year-old daughter has always been prone to respiratory problems, which were typically brought on mostly with colds or allergies. On those particular nights, she(we) would be kept up coughing. Many nights I sat on her bed holding her upright on pillows all night, sitting on the toilet with her steaming away in the bathroom or as a last resort, pumping her with steroid inhalers.

All I do now is rub a little Respiratory Relief (diluted massage oils) on her little chest, and a few coughs later she is peacefully asleep! It has also worked for my husband and myself. I shared this tip and my oils with my neighbor who's daughter came home from preschool with croup. The next morning she came over to my house so excited. Her daughter woke up healthy and rested and she sent her right back to preschool. The more I explore, the more I am loving these oils!

3. I rubbed my little one down with Respiratory Relief and Peppermint when she turned up not feeling well. She still wasn't herself that evening, but then when she woke up on then next morning she was fine except she said she had a stomach ache. I rubbed Peppermint on her stomach, and now she is just fine. She has had chronic croup all winter long except for this winter. Since using Peppermint and Respiratory Relief consistently, she has had no croup and has been well all winter.

4. A friend of mine called saying her children (ages 3.5 and 5) were miserable with a croupy cough, and asked if I could suggest some oils to help. I loaned her my Lung Support and some Natural/Organic carrier oil. I suggested that she rub a couple of drops on her kids' chests, backs and soles of feet. She called back later that day to report that within 15 minutes of putting the oils on, both children stopped coughing! Thank God for these wonderful oils!
[HEO's Comment: Due to Birch, Lung Support is not suitable for children.]

5. My first big experience with essential oil came about a month after I started using them. I wanted to find something that would help my son with the croup. He was six at the time, but had been having episodes of croup since he was two. One night he started to get a barking cough. This was the first sign that it was going to be a bumpy night. The barking cough always led to difficult breathing and spending the night in a steamy bathroom getting him to try to breathe. Not fun and very scary!

At the first sign of the barking, I applied a few drops of Respiratory Relief on his chest. I then felt inspired to use Ancient Defense on his feet. I rubbed on the oils, held his feet and said a prayer that they would work and that the Lord would give me wisdom for how to help him.

I told him to lie still and concentrate on breathing and that I would be back to check on him in about ten minutes. When I came back ten minutes later, he was asleep! I was shocked. That had never happened before. I went back to my room and waited for the barking, but I heard nothing. I stayed up listening and waiting. In the morning he had a little cough, but that was as far as it went.

He had the beginnings of a croup attack one more time a few months later. The barking started and I got out my oils. The same thing happened again. He fell asleep. Now, five years later, he has never had another croup attack. I am so grateful that a friend encouraged me to try essential oils.

6. Please extend a huge thank you and heaps of gratitude to your team! I never expected to order on Saturday morning and have my package out for delivery today, but it is greatly appreciated! My little guy started coughing EARLY Saturday morning so badly that he couldn't sleep and it sounded like it might be croup. It took me a couple hours, but I finally remembered that I had a sample bottle of Breathe Easy tucked away. Within minutes of applying it to his feet and inner thighs, I could see him visibly relax and he was finally able to sleep. - Heather

7. Recently I was shopping with my 86-year-old mother and my sister. My mother started her usual deep cough, which is very hard to listen to because it is a dry cough like croup. I had just gotten the Respiratory Relief blend and hadn't used it yet myself. I told her to rub it on her chest. She never coughed again the rest of the time I was with her, which was about four hours.

My sister was having trouble with the smells in the clothing store we were in that same day and thought she couldn't stay there because she was itching so much. I told her to rub Respiratory Relief on the bridge of her nose, under her nostrils and inhale it for several breaths. Within minutes she asked what that was because it worked, and she had no more problems.

Over Christmas when mom stayed at my sister’s house, she was bothered by dog hair with sneezing, runny nose and itchy eyes. Again, she just kept inhaling and rubbing the Respiratory Relief oil on several times a day and had no more problems with her allergies.

8. A rotation of Warrior, Plague Defense and Top Gun kept RSV that my husband had developed from spreading to me and our son, who had just arrived from China with who-knows-what uninvited bugs and viruses, together in our very small cottage. - Fran

References
Purchon, Nerys; Cantele, Lora, Complete Aromatherapy and Essential Oils Handbook for Everyday Wellness, page 171.
Tisserand, Robert; Young, Rodney, Essential Oil Safety: A Guide for Health Care Professionals, Elsevier Health Sciences UK 2nd Edition 2014, page 104.