History
The clinical manifestations of most acute viral meningitides may vary with the particular virus. Illness may be biphasic, with nonspecific constitutional symptoms followed by meningitis. The epidemiologic setting (e.g., time of year, geographic locale, exposure to insects, prevalent illnesses in the local community) and accompanying systemic manifestations may be helpful in making a presumptive diagnosis.
A detailed drug history is invaluable for identifying possible drug-induced aseptic meningitis, which has a clinical presentation indistinguishable from infectious meningitis. The drug history must include nonprescription medications such as ibuprofen.
The time course of acute viral meningitis varies. Onset may occur within a matter of hours after exposure or evolve more slowly over a few days. Usually, maximum deficit appears within 3-6 days after exposure. Persons infected with the viruses that commonly cause aseptic meningitis may remain infectious for weeks after contracting the virus.
Characteristic signs of acute viral meningitis include the following:
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Headache
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Fever
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Stiff neck
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Photophobia
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Drowsiness
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Myalgias
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Malaise
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Chills
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Sore throat
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Abdominal pain
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Nausea and vomiting
Focal signs, seizures, and profound lethargy are rarely features of aseptic meningitis. Occasionally, patients may exhibit altered levels of consciousness, including confusion and visual hallucinations.
Physical Examination
Meningeal signs
Neck stiffness in meningitis is tested by gentle forward flexion of the neck with the patient lying in the supine position. Meningeal irritation also can be tested by the jolt accentuation of headache. This is elicited by asking the patient to turn his or her head horizontally at a frequency of 2-3 rotations per second. Worsening of a baseline headache represents a positive sign.
Severe meningeal irritation may result in the patient assuming the tripod position (termed Amoss sign or Hoyne sign) with the knees and hips flexed, the back arched lordotically, the neck extended, and the arms brought back to support the thorax.
When passive neck flexion in a supine patient results in flexion of the knees and hips, the Brudzinski sign is positive. Yet another Brudzinski sign, the contralateral reflex, is present if passive flexion of one hip and knee causes flexion of the contralateral leg.
Kernig sign is elicited with the patient lying supine and the hip flexed at 90°. A positive sign is present when extension of the knee from this position elicits resistance or pain in the lower back or posterior thigh.
Papilledema or absence of venous pulsations upon funduscopic examination indicates increased intracranial pressure.
Rash
Skin manifestations may suggest the diagnosis of aseptic meningitis from certain causes. Examples include the rash of varicella zoster, the genital lesions of HSV-2, or a mild maculopapular rash occurring in the summer and fall months with some enteroviruses.
Rash from enteroviral infections usually accompanies the onset of fever and persists for 4-10 days. In infections due to coxsackieviruses A5, 9, or 16 or echoviruses 4, 6, 9, 16, or 30, the rash is typically maculopapular and nonpruritic, may be confined to the face and trunk, or may involve extremities, including the palms and soles.
In coxsackievirus A16 and, rarely, in other group A serotype infections, a vesicular rash may involve the hands, feet, and oropharynx. Herpangina, characterized by gray vesicular lesions on the tonsillar fossae, soft palate, and uvula, can accompany infection caused by group A coxsackievirus. With echovirus 9 infections, a petechial rash resembling meningococcemia typically is observed.
