hello and welcome to health care magic, I am Dr Sriram Nathan, an ENT surgeon and I will try to help you out with your problem I see that the lump in the oral cavity or mouth is bothering you. You must understand that there maybe so many lump like masses in the oral cavity and throat which are perfectly normal and they can be of so many different shape, size and colour. Your allergy and sinus problem will not have anything to do with the lump. However if the lump is lymphoid in nature then in all probability it may enlarge when you have any infection so that link may still be there with your allergies and sinus and the lump. You must at the offset just relax and do these: - watch if the lump is increasing in size and shape and is getting painful. If it does then you must get an ENT consult - In any case I would recommend you to take a diagnostic nasal endoscopy and CT PNS so that we can rule out sinsusitis and also get more details about the lump - try an antihistamine like levocetrizine for your allergies and see if the lump also responds to the same. Your doctor will know about this Hope your doubts are clear and I will be happy to clear any more regards Dr Sriram Nathan

---