Introduction To Lyme Disease

 Circular red rash with central clearing characteristic of Lyme disease. Rash is known as Erythema chornicum migrans.

Introduction: Caused by the spirochete Borrelia burgdorferi, Lyme disease is transmitted by the bite of the deer tick (Ixodes dammini).
Although reported in most states, it appears to be predominant in the Great Lakes area and the Western and Northeastern United States.

Clinical features: The symptoms occur in three stages:

First stage. This stage usually begins with malaise, fever, headache, stiff neck, and back pain. Generalized lymphadenopathy with splenomegaly occurs, and a large annular erythematous lesion forms at the bite site and shows central clearing (erythema chronicum migrans). Multiple lesions may occur and affect other areas of the body. The lesions are warm but not often painful. As many as 25% may not exhibit skin manifestations. These symptoms usually appear within a few days to up to 1 month after the tick bite.

Second stage. This is the disseminated stage. Complications include carditis with AV block, palpitations, dyspnea, chest pain, and syncope. Pericarditis may also occur. Neurologic manifestations, including peripheral neuropathies and meningitis, are sometimes present. Large-joint arthritis is also common.

A 42 Year Old Alcoholic Man Presents With Cough And Fever

A 42-year-old alcoholic man develops cough and fever. Chest x-ray is shown below which shows an air-fluid level in the superior segment of the right lower lobe.

Which of the following is the most likely etiologic agent?

a. Streptococcus pneumoniae
b. Haemophilus influenzae
c. Legionella pneumophila
d. Anaerobes
e. Mycoplasma pneumoniae

Answer And Discussion:

A Patient With Klebsiella pneumoniae Infection

A patient in the hospital develops pleuritic chest pain, shortness of breath, fever, chills, productive cough, and colored sputum after 3 days of being in the hospital for major surgery.
Physical examination shows tenderness to palpation without any areas of increased tactile fremitus. Blood and sputum cultures confirm gram-negative rods that ferment lactose, have a large mucoid capsule, and form viscous colonies.
The patient subsequently dies from her infection. Which of the following is most likely to be found at autopsy?

(A) Acute inflammatory infiltrates from bronchioles into adjacent alveoli
(B) Congestion, red hepatization, gray hepatization, and resolution
(C) Diffuse, patchy inflammation localized to the alveolar wall interstitium
(D) Intra-alveolar hyaline membranes without alveolar space exudates
(E) Predominantly intra-alveolar exudate resulting in consolidation.

Answer And Discussion: