This study aims to assess Sinonasal risk factors for occurrence of unilateral versus bilateral allergic fungal rhino sinusitis regarding::

1. anatomical variations and correlate radiological finding with intraoperative finding.
2. other associated factors like demographic ,environmental, immunological and climatic risk factors .

Introduction Allergic fungal rhinosinusitis (AFRS) is a subtype of CRS with nasal polyposis (CRSwNP) that is characterized by eosinophilic mucin within expanded sinus cavities and immunoglobulin E (IgE)-mediated type 1 hypersensitivity to fungal elements. This noninvasive disease process typically affects immunocompetent, younger patients in geographic regions with warm temperatures and high humidity, which facilitate fungal proliferation.

AFRS has a worldwide distribution pattern with varying prevalence. AFRS is presented in variable rates in different climatic, socioeconomic, and geographic factors. The disease prevalence showed predilection toward climatic factors

Inclusion criteria:

Denovo cases . any Age Any sex. Patients diagnosed with unilateral or bilateral allergic fungal rhino sinusitis, meeting classic Bent and Kuhn criteria for AFRS:(10).

Nasal polyposis. Fungi on staining. Eosinophilic mucin without fungal invasion into sinus tissue., Type I hypersensitivity to fungi. Characteristic radiologic findings with soft-tissue differential densities on computed tomographic (CT) scanning

Exclusion criteria:

Diagnosis of benign or malignant neoplasm of the sinonasal cavity. Prior radiation therapy to the head or neck. Significant prior facial trauma. Autoimmune disorder. Craniofacial anomaly. Fungus ball. Immunodeficiency. Cystic fibrosis. Patients unfit for surgery. Previous nasal surgery or recurrent cases .

Patients will be divided into two groups:

Group (A): including patients with unilateral allergic fungal rhinosinusitis. Group (B): including patients with bilateral allergic fungal rhinosinusitis. Then all patient will subjected to EFSS under general anathesia with wide sinusotomics where intraoperative collection of data will be done as the follow