Most so-called sinus headaches may actually be migraines in disguise
A throbbing face and forehead feels like a blocked sinus, yet a 2005 review concluded that most sinus headaches are really migraines. The same trigeminal nerve serves both the sinuses and the membranes around the brain, so the pain is hard to place. A giveaway: migraine rarely brings the thick discharge of a true infection.
Sinusitis, or rhinosinusitis, is inflammation of the membranes lining the air spaces around the nose. It is very common, striking somewhere between a tenth and nearly a third of Americans and Europeans annually, and its management there reportedly costs more than 11 billion dollars. Most cases start with a viral cold, often from rhinoviruses, coronaviruses or influenza, and viral episodes usually last 7 to 10 days. When bacteria are responsible, three species dominate, led by Streptococcus pneumoniae.
Doctors classify it by duration. Acute sinusitis lasts under four weeks, subacute between 4 and 12, and chronic at least 12 weeks. The chronic form is now seen as a multifactorial inflammatory disorder rather than a lingering infection, sometimes involving polyps, a bent nasal septum or allergy, and it often dulls the sense of smell. Smoking, secondhand smoke and fine PM2.5 air pollution are all associated with it; particles that small slip past nasal hairs and settle in sinus linings. The role of fungi in chronic cases is still debated, and antifungal trials have given mixed results.
Where the pain appears depends on which of the four paired sinuses is inflamed. The maxillary sinuses in the cheeks can mimic toothache, frontal sinuses cause forehead pain, ethmoidal ones ache between the eyes, and the deep sphenoidal sinuses can refer pain to the top or back of the head. Sinus pain typically worsens when the head tilts forward, which helps tell it apart from a bad tooth. Infections can also travel the other way, from a tooth into the maxillary sinus.
Serious complications are rare, around one case in 10,000, but the sinuses sit close to the eyes and brain. Infection can spread into the eye socket, graded in five stages by the Chandler classification, or into bone, where frontal infection with an abscess is known as Pott's puffy tumour. Since most cases are viral, guidance favours watchful waiting at first. Researchers have also found that counting recurrent sinusitis episodes in health records helps flag people with immune deficiencies.
Source: Sinusitis
