Case Study 37By Chris Sanders

History of Present Illness

86 y.o. male

Mosquito bite

Swelling around right eye

Bit 96 hours ago

Severe periorbital edema

Mild fever

Mild headache

Review of Systems

Alert and oriented

Doctor suspects arthropod

Follow up appointment with neurologist and infections diseases specialist

OTC ibuprofen

Ice to swollen area

Acute Viral Encephalitis

• What is the pathophysiology of swelling in this case?

• Why is the application of ice helpful to relieving swelling in this case?

• Based on the patient’s location when he received the mosquito bite, what are several possible diagnoses?

• Based on incubation period only, identify two potential types of encephalitis in this patient.

• Are any of the infections that you listed above in your answer to question 3 potentially serious?

Clinical Course

Confused

Disoriented

Mild tremors

Severe headache

Previous Medical History 18 months S/P cadaveric

renal transplantation

ESRD secondary to DM type 1, diagnosed 10 yrs

CAD

COLD x 6 yrs

Asthma

DM type 1 diagnosed at 13

Medications Nitroglycerin SR 6.5 mg po Q

8h

Nitroglycerin 0.4 mg SL PRN

Theo-Dur 100 mg po BID

Albuterol MDI 2 puffs QID PRN

Atrovent MDI 2 puffs BID

Cyclosporine 250 mg po BID

Prednisone 10 mg po QD

Mycophenolate mofetil 1500 mg po BID

Insulin: NPH insulin 16 u @ breakfast and Lispro

Blood Glucose (mg/dL)

Units @ breakfast

Units @ lunch

Units @ supper

Units @ Bedtime

<80 4 - - -

81-150 5 - 8 -

151-200

6 - 9 1

201-250

7 2 10 2

251-300

8 3 11 3

301-350

9 4 12 4

351-400

10 5 13 5

>400 11 6 14 6

Three of the drugs listed above are of particular concern in this patient.

Which three drugs should cause concern and why should they cause

concern?

Nitroglycerin Dizziness, headaches, lightheadedness

Theo-Dur Dizziness, headaches, lightheadedness

Albuterol

Atrovent

Cyclosporine/Prednisone

Dizziness, headaches

Headache, eye pain

Suppresses immune system

Mycophenolate mofetil Suppresses immune system

PE and Lab Tests Disoriented, pale, mild

tremors, appears ill

BP 150/95

P 105 and regular

RR 17 and unlabored

T 100.5º F

Warm and pale skin

No rash observed

PE and Lab Tests Cont. PERRLA

EOM intact

Fundi reveal old laser scars bilaterally w/o hemorrhages and occasional hard exudates bilaterally

Ears and nose unremarkable with no bulging of TMs

Mucous membranes dry

Mild non-exudative pharyngitis present

Wears dentures

PE and Lab Tests Cont. Thyroid normal

Cervical and axillary lymph nodes palpable (~2cm)

Sinus tachycardia

Chest normal

Abd normal

Rect normal

Ext normal

PE and Lab Tests Cont. Disoriented

Mild tremor in both hands

DTRs 2+

(+) Kernig sign

(+) Brudzinski sign

Muscular strength 3/5

Decreased sensation in feet (diabetic neuropathy)

• Suggest a reasonable explanation for the laser scars in the eyes?

• Suggest a reasonable pathophysiologic explanation for the patient’s enlarged lymph nodes.

• Although not routine practice, why were this patient’s feet carefully examined for lesions?

• What is suggested by the positive Kernig and Brudzinski signs?

Lumbar Puncture Results Significant lymphopenia

Mild diffuse cerebral edema with no intra-cerebral bleeding

CSF lymphocytosis

Normal glucose

No CSF RBCs

Moderately elevated protein

Normal lactic acid

Gram stain (-)

Bacterial culture (-)

IgM antiviral antibody (+)

Enzyme Immunoassay with Plaque Reduction Neutralization Test

West Nile Virus

• Based on all the available clinical evidence above, what is a likely diagnosis for this patient’s condition?• What is an appropriate treatment

approach for this patient?