Chapter 136. Meningococcal Infections (Part 6) docx

Meningococcal Infections Part 6 Clinical Manifestations Upper Respiratory Tract Infections Although many patients who develop meningococcal meningitis or meningococcemia report having

Chapter 136 Meningococcal Infections

(Part 6)

Clinical Manifestations

Upper Respiratory Tract Infections

Although many patients who develop meningococcal meningitis or meningococcemia report having had throat soreness or other upper respiratory symptoms during the preceding week, it is uncertain whether these symptoms are due to infection with meningococci Meningococcal pharyngitis is rarely

diagnosed Adult patients with N meningitidis bacteremia more often have

clinically apparent disease of the respiratory tract (pneumonia, sinusitis, tracheobronchitis, conjunctivitis) than do younger patients

Meningococcemia

Patients with meningococcal disease may have both meningococcemia and meningitis These conditions have a wide clinical spectrum, with many overlapping features

Approximately 10–30% of patients with meningococcal disease have meningococcemia without clinically apparent meningitis Although meningococcal bacteremia may occasionally be transient and asymptomatic, in most individuals it is associated with fever, chills, nausea, vomiting, and myalgias Prostration is common The most distinctive feature is rash Erythematous macules rapidly become petechial and, in severe cases, purpuric (see Fig 52-5) Although the lesions are typically found on the trunk and lower extremities, they may also occur on the face, arms, and mucous membranes The petechiae may coalesce into hemorrhagic bullae or may undergo necrosis and ulcerate Patients with severe coagulopathy may develop ischemic extremities or digits, often with a sharp line

of demarcation between normal and ischemic tissue

In many patients with fulminant meningococcemia, the CSF may be normal and the CSF culture negative Indeed, the absence of meningitis in a patient with meningococcemia is a poor prognostic sign; it suggests that the bacteria have multiplied so rapidly in the blood that meningeal seeding has not yet occurred or had time to elicit inflammation in the CSF Most of these patients also lack evidence of an acute-phase response; i.e., the erythrocyte sedimentation rate is normal, and the C-reactive protein concentration in blood is low

The Waterhouse-Friderichsen syndrome is a dramatic example of

DIC-induced microthrombosis, hemorrhage, and tissue injury Although overt adrenal failure is infrequently documented in patients with fulminant meningococcemia,

patients may have partial adrenal insufficiency and be unable to mount the normal hypercortisolemic response to severe stress or cosyntropin stimulation Almost all patients who die from fulminant meningococcemia have adrenal hemorrhages at autopsy

Chronic meningococcemia (Fig 136-4) is a rare syndrome of episodic

fever, rash, and arthralgias that can last for weeks to months The rash may be maculopapular; it is occasionally petechial Splenomegaly may develop If untreated or if treated with glucocorticoids, chronic meningococcemia may evolve into meningitis, fulminant meningococcemia, or (rarely) endocarditis

Figure 136-4

Erythematous papular lesions are seen on the leg of this patient with

chronic meningococcemia (Courtesy of Kenneth M Kaye, MD, and Elaine T

Kaye, MD; with permission)

Meningitis

(See also Chap 376) Common presenting symptoms of patients with meningococcal meningitis include nausea and vomiting, headache, neck stiffness, lethargy, and confusion The symptoms and signs of meningococcal meningitis cannot be distinguished from those elicited by other meningeal pathogens Many patients with meningococcal meningitis have concurrent meningococcemia,

however, and petechial or purpuric skin lesions (see Fig 52-5) may suggest the correct diagnosis CSF findings are consistent with those of purulent meningitis: hypoglycorrhachia, an elevated protein concentration, and a neutrophilic leukocytosis A Gram's stain of CSF is usually positive (see "Diagnosis," below); when this finding is unaccompanied by CSF leukocytosis, the prognosis for normal recovery is often poor

Other Manifestations

Arthritis occurs in ~10% of patients with meningococcal disease When arthritis develops during the first few days of the patient's illness, it usually reflects direct meningococcal invasion of the joint Arthritis that begins later in the course

is thought to be due to immune complex deposition Primary meningococcal pneumonia occurs principally in adults, often in military populations, and is often due to serogroup Y While meningococcal pericarditis is occasionally seen,

endocarditis due to N meningitidis is now exceedingly rare Primary

meningococcal conjunctivitis can be complicated by meningococcemia; systemic therapy is therefore warranted when this condition is diagnosed Meningococcal urethritis has been reported in individuals who practice oral sex