Porth's Essentials of Pathophysiology, 4e

541

Respiratory Tract Infections, Neoplasms, and Childhood Disorders

C h a p t e r 2 2

In contrast to acute infections, the pathogens found in chronic rhinosinusitis are usually a mixture of aero- bic and anaerobic bacteria, including Staphylococcus aureus , coagulase-negative Staphylococcus , and anaero- bic gram-negative bacilli. Although the mechanisms that contribute to the chronicity of the disorder are uncer- tain, mucociliary dysfunction, mucostasis, hypoxia, and release of microbial products are thought to play a role. Allergies may also play an important role in the pathogenesis of chronic rhinosinusitis. In immunocom- promised persons, such as those with human immuno- deficiency virus (HIV) infection, the sinuses may become infected with gram-negative species and opportunistic fungi. In persons in this group, particularly those with leukopenia, the disease may have a fulminant and even fatal course. Manifestations. The symptoms of acute viral rhinosi- nusitis often are similar to those of the common cold and allergic rhinitis 7–12 (discussed in Chapter 16). They include facial pain, headache, purulent nasal discharge, decreased sense of smell, and fever. A history of a pre- ceding common cold and the presence of purulent nasal drainage, pain on bending, unilateral maxillary pain, and pain in the teeth are common findings with involve- ment of the maxillary sinuses. The symptoms of acute viral rhinosinusitis usually resolve within 5 to 7 days without medical treatment. Acute bacterial rhinosi- nusitis is suggested by symptoms that worsen after 5 to 7 days or persist beyond 10 days, or symptoms that are out of proportion to those usually associated with a viral upper respiratory tract infection. Persons who are immunocompromised, such as those with leukemia, aplastic anemia, bone marrow transplant, or HIV infec- tion, may present with fever of unknown origin, rhinor- rhea, or facial edema. Often, other signs of inflammation such as purulent drainage are absent. In persons with chronic rhinosinusitis, the only symptoms may be nasal obstruction, a sense of fullness in the ears, postnasal drip, hoarseness, chronic cough, and loss of taste and smell. Sinus pain often is absent; instead, the person may complain of a headache that is dull and constant. Persons with chronic rhinosinus- itis may have superimposed bouts of acute rhinosinus- itis. The mucosal changes that occur during acute and subacute forms of rhinosinusitis as usually reversible; whereas, those that occur during chronic rhinosinusitis may be irreversible. Diagnosis. The diagnosis of rhinosinusitis usually is based on symptom history and a physical examination that includes inspection of the nose and throat. Headache due to sinusitis needs to be differentiated from other types of headache. Sinusitis headache usually is exagger- ated by bending forward, coughing, or sneezing. Physical examination findings in acute bacterial sinusitis include turbinate edema, nasal crusts, purulent drainage, and failure of transillumination of the maxillary sinuses. Transillumination is done in a completely darkened room by placing a flashlight against the skin overlying the infraorbital rim, directing the light inferiorly, having the

Frontal sinus

Ethmoid sinuses

Maxillary sinus

A

Cranial cavity

Frontal sinus

Anterior ethmoid Middle turbinate Osteomeatal complex

Orbit

Maxillary ostium

Inferior turbinate

Maxillary sinus

Nasal septum

B

Frontal sinus

Sphenoidal sinus

Superior turbinate

Middle turbinate

Inferior turbinate

Acute rhinosinusitis may be of viral, bacterial, or viral–bacterial etiology. In most cases, bacterial infection is preceded by a viral upper respiratory infection, which in turn leads to inflammation and obstruction of the ostiomeatal complex. Rhinovirus is the most common viral pathogen. Haemophilus influenzae , Streptococcus pneumoniae, and Moraxella catarrhalis make up the majority of community-acquired bacterial pathogens. C FIGURE 22-1. Paranasal sinuses. (A) Frontal view showing the frontal, ethmoid, and maxillary sinuses. (B) Cross-section of nasal cavity (anterior view).The shaded area is the osteomeatal complex, which is the final common pathway for drainage of the anterior ethmoid, frontal, and maxillary sinuses. (C) Lateral wall, left nasal cavity showing the frontal sphenoidal sinuses and the superior, middle, and inferior turbinates.