Hello I have gone through your question and understand your concern. Acute sinusitis is one the most common upper respiratory tract infection and can be caused by bacterial, fungal, viral infections or allergies, nasal polyps. Other common causes of sinusitis are nasal tumour, tooth infections, deviated nasal septum, immune system disorders, gastroesophageal reflux, cystic fibrosis. Frontal headache is a symptom of blocked frontal sinus and treating the blocked sinus will eventually give a relief from headache. Expect antibiotic therapy, treating underlying cause, pain killers and surgical drainage of sinus( if needed) as a part of treatment. Thank you.