Doxycycline in Treating Patients With Chronic Rhinosinusitis With Nasal Polyps

Inclusion Criteria: * Nasal polyps on nasal endoscopy. * The patient has moderate to severe disease, defined by moderate to severe subjective symptoms (a score greater than 3 on a 10-cm VAS). * The patient is at least 18 years old. * The patient is able to understand and give informed consent. * The patient has clinically diagnosed chronic rhinosinusitis with nasal polyps according to the AAO-HNS diagnostic criteria: At least 2 of the following symptoms/signs: * Mucopurulent drainage (anterior, posterior, or both) * Nasal obstruction (congestion) * Facial pain-pressure-fullness * Decreased sense of smell * and symptoms lasting 12 weeks or longer. Exclusion Criteria: * The patient has a history of treatment with oral corticosteroids in the past 4 weeks. , * The patient has cystic fibrosis. * The patient has primary ciliary dyskinesia. * The patient has diabetes. * The patient has had sinus surgery in the past 3 months. * The patient has an allergy to doxycycline or related tetracyclines or glucocorticoids. * The patient is a minor. * The patient is a prisoner. * The patient has a psychiatric illness or developmental delay, which would interfere with understanding of the study and provision of informed consent. * The patient is a breastfeeding mother. The effects of the drugs used in this study (doxycycline) on breast milk are unknown and thus, these patients will be excluded from the study * The patient has a history of HIV or other known cause of immunosuppression, or is actively taking immunosuppressive medications due to organ transplantation, rheumatoid disease, or other medical conditions. * The patient is on penicillin; antacids containing aluminum, calcium, magnesium, or iron; bismuth subsalicylate; barbiturates; carbamazepine; and phenytoin; as well as tetracycline and Penthane. * Pregnancy. Doxycycline, a tetracycline, is a known teratogen. For this reason women of child-bearing potential are suggested to take a form of contraception for the duration that they are taking doxycycline., Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately. Pregnancy Testing. Women of childbearing potential are required to have a negative serum pregnancy test (with a sensitivity of at least 25 mIU/mL) prior to the first dose of drug. No further pregnancy tests are required since after this visit the patient will no longer be taking tetracycline after 3 weeks. Women of childbearing potential are defined as follows: * Patients with regular menses * Patients with amenorrhea, irregular cycles, or using a contraceptive method that precludes withdrawal bleeding * Women who have had a tubal ligation Women are considered not to be of childbearing potential for the following reasons: * The patient has undergone hysterectomy and/or bilateral oophorectomy. * The patient is post-menopausal defined by amenorrhea for at least 1 year in a woman \> 45 years old.