Allergic rhinitis 5 yr old boy

Hello All,
My 5 year old son has been suffering from allergic rhinitis since last 3 years. that's what my GP dianosed. the symptoms goes like this.
- watery runny or blocked nose
- Face eyes and nose turns sightly red.
- Sudden persistant cough.he gets very tired from the cough episodes.
- Leads to frotty vomit and crying.
- Mild to high fever.
- Wakes up at night, blocked nose, unstoppable coughing, crying.
- Gets up morning coughing. Sneezes 4-6 times with big snort coming out. Clear to slightly yellow.
- voice becomes hoarse.
He gets this rhinitis often, at least twice per month.
and misses school a lot.
I cannot continue giving him Aerius and steroid nasal spray all the time.
He is thin, fair, below ideal weight and is very active and creative. Likes to draw.
Small appetite. Anxious and tends to retracts in unknown environment.