Dear Peg,
Easy and natural remedy is steam inhaling use camomile infusion and/ or seasalt in the hot water as it is calming cleansing and antiseptic.
Otherwise you could look at the actual drainage of nasal, sinuses, lacrimal glands for which a simpe drainage massage, facial massage, accupressure massage would help, The problem could also be due to misalignments of several structures in the area (did he have a difficult birth or possibly an accident?) to check this out and get treated you could consult a craniosacral therapist.
Also watch out for a pattern connected to the two months cycle ( e.g. what does he it then? does he stay with friends at the time and eats differently? does he wear glasses?...)
hope this helps
ange