Chronic sinusitis means that symptoms have been present for greater than 90 days, or 3 months. unlike acute sinusitis, chronic sinusitis is usually not simply driven by infection but is better understood as an inflammatory syndrome. Sinusitis is an infection of the sinuses near the nose. there are three types of sinusitis: with previous infections that were inadequately treated, and lasts longer than three months the symptoms of sinusitis depend on the ag. 3 month old baby. the magic 3 month period has arrived and with it a whole new range of developmental changes for your baby. if the last few weeks have been heavy going and your baby has been more than a little unsettled, then this month could be the turning point. Jan 10, 2020 · check for the following symptoms of sinus infection in babies: nasal congestion or cold that lasts for more than ten to 14 days. green-yellow discharge from the nose for more than four days. a bad cough in the daytime that becomes worse at night. 8 Symp...