BACKGROUND Mucosal epithelial cells which line the upper respiratory passage are affected by the acute allergic reactions. The interactions that take place between the allergens and the surface are complex and involve the autonomic nervous system and the mediators produced by the underlying tissues in response to allergens. Mucous glands which have goblet cells in the epithelium are induced to secrete mucus and the mucus genes are induced in the ciliated epithelium. This caused mucous metaplasia and hyperplasia. Thus, repeated and prolonged exposure leads to structural changes and enhanced mucous production. The tissues will be washed with cytokines and other inflammatory mediators which cause classical pictures of asthma. Structural abnormalities that are commonly encountered in the practice of ENT are sinusitis and nasal polyps. The sinusitis is caused by prolonged inflammation of the mucosa and thus excess production of the mucus and this leads to the obstruction of the natural drainage. Nasal polyp is oedematous and hypertrophied mucosal and submucosal tissue presenting as a mass lesion. A sincere effort has been made to find out the common allergens that cause the respiratory complications in the practice of ENT. This study is intended to help the fellow ENT practitioners to identify the commonly associated allergens and thus take immediate actions in diagnosing and treating the patient that present in complications in OPD.