Sinusitis is mainly due to allergic reaction of sinus cavities. Such allergic manifestations are over reaction of immune system of some individuals. Homoeopaths treat such cases based on individuality considering the constitution, symptomatic presentations, modalities, miasm, etc. Usually prescribed remedies for chronic sinusitis are Arsenicum album, Calcarea carbonica, Cinnabaris, Hydrastis Canadensis, Kalium chloricum, Kalium iodatum, Lycopodium, Medorrhinum, Mercurius, Nux vomica, Pulsatilla, Sanguinaria, Silicea, Thuja, etc.  Repeated attacks may lead to chronicity.  Steam inhalation may be used if prescribed. Sufferer should consult a homoeopath for the drug suitable to you based on the individuality as mentioned above and go by his advice.