Thick mucus from Nose is Bacterial infection..
Normally a allergy or viral fever brings superadded bacterial infection..
Does he had Sinusitis before or some sort of Allergy?
Next Steps
take fexofenadine+ monteleucast combination tablets.
Health Tips
sinusitis if it's there may be the core issue..once it gets cured nothing will happen in future.. Sinusitis needs exercise etc.