Allergic Rhinitis Ebook
In hay fever, the allergen-reagin reaction occurs in the nose. Histamine released in response to the reaction causes local intranasal vascular dilation, with resultant increased capillary pressure as well as increased capillary permeability. Both these effects cause rapid fluid leakage into the nasal cavities and into associated deeper tissues of the nose and the nasal linings become swollen and secretory. Here again, use of antihistamine drugs can prevent this swelling reaction. But other products of the allergen-reagin reaction can still cause irritation of the nose, eliciting the typical sneezing syndrome.
The majority of patients with AFRS present with gradual progressive nasal airway obstruction, semisolid nasal crusts, and a history of chronic allergic rhinitis 25 . Occasionally, the initial symptom patients present to the physician with is gross facial dys-morphia 21, 22 or acute vision loss 27 . The facial dysmorphic features can include proptosis 4 and telecanthus 27 , where orbital involvement can lead to diplopia, visual field cuts, and acute vision loss (Fig. 11.2). These features are all caused by the expansile nature of AFRS. As the sequestered allergic mucin accumulates, it exerts an outward pressure on the surrounding structures. Bony remodeling and decalcification, similar to a mucocele, may occur 14, 16, 34 . This can result in a clinical picture that mimics invasion, much like a malignant process.
The majority of cases of rhinosinusitis are secondary to obstruction of the ostiomeatal unit, which is an area located in the middle meatus. This obstruction will lead to poor ventilation and stasis of secretions, resulting in inflammation or infection. Obstruction can be due to several causes, the most common being anatomical anomalies, viral infections and allergic rhinitis. Certain conditions that can affect mucociliary clearance of the sinuses can also cause rhinosinusitis. Such conditions include cystic fibrosis, ciliary dyskinesia and immotile cilia. Several other conditions can affect the development of rhinosinusitis. Other than allergic rhinitis, immune deficiencies and reflux disease are conditions that may impact the response to treatment of rhinosinusitis 4, 19, 20 .
ATOPIC DISEASE AND ATOPIC ECZEMA Atopic conditions include asthma, allergic rhinitis, urticaria, and atopic dermatitis. These conditions are generally associated with elevated serum IgE levels and serum IgE responses to allergens. The role of IgE and exogenous antigens in atopic dermatitis is extremely
Onstrated that the mucocele lining is composed of normal respiratory mucosa, namely, ciliated pseudostrati-fied columnar epithelium. Thus, the development of a mucocele can be extrapolated to an event resulting in retained mucus with loss of a normal outflow tract. One proposed mechanism implicates the cystic degeneration of a seromucinous gland with formation of a retention cyst 2 . Sinus outflow obstruction resulting from benign or malignant intranasal neoplasm may also contribute to mucocele formation. Iatrogenic mucocele formation was demonstrated in the setting of both external and endoscopic sinus surgery secondary to trapped mucosa or scarring of a paranasal sinus ostium. One series reported a 9.3 incidence of frontal sinus mucocele following osteoplastic flap 8 . Other etiologic factors include a history of chronic rhinosinusitis, allergic rhinitis, and previous maxillofacial trauma.
Atopic eczema is a chronic, relapsing pruritic dermatitis that usually occurs in adults and is localized to the flexural surfaces of the face, neck, cubital or popliteal fossa, and hands. The dermatitis usually occurs in patients with a personal or family history of atopy or hay fever asthma urticaria lesions may present as papular, scaly, or chronic lichenified plaques. The cause is unknown but is believed to be IgE mediated. fill
The course varies from a mild single episode to severe chronic, recurrent episodes resulting in the psychoitchical person. The infantile form usually becomes milder or even disappears after the age 3 or 4 years and approximately 70 of cases clear by puberty. During puberty and the late teenage years, flare-ups or new outbreaks can occur. Young housewives or househusbands may have their first recurrence of atopic eczema since childhood due to their new job of dishwashing and child care. Thirty percent of patients with atopic dermatitis eventually develop allergic asthma or hay fever. Heredity is the most important single factor. The family history is usually positive for one or more of the triad of allergic diseases asthma, hay fever, or atopic eczema. Determination of this history in cases of hand dermatitis is important because often it enables the physician, on the patient's first visit, to prognosticate a more drawn-out recovery than if the patient had a simple contact...
In patients complaining of anosmia or hyposmia, it is useful to ask whether smell function is diminished or completely lost, localized to the right or left nostril, or both, and whether the dysfunction is for all odorants or only a few. Patients with loss due to nasal sinus disease are more likely to experience a gradual loss of function than those who have loss due to a prior upper respiratory infection or to head trauma. Some patients report temporary recovery of function in circumstances in which nasal patency is increased, such as on warm days or during exercise, showering, or treatment with corticosteroids this implies a problem with intranasal airway blockage (as in allergic rhinitis) rather than a sensorineural problem.