Differential Diagnosis

Differential Diagnosis I: Rheumatoid Arthritis

A chronic systemic inflammatory autoimmune disease distinguished by joint swelling, tenderness and destruction of synovial joint leading to disability and premature death. In addition to the inflammation of the joint, Rheumatoid Arthritis (RA) can cause fever, malaise, rash, lymph node or spleen enlargement, and Raynaud Phenomenon to the finger tips and toes (McCance & Huether, 2014).

Clinical Manifestations:

RA is usually insidious.  It begins with systemic inflammation, fever, malaise, anorexia, fatigue, weight lost, general aching and stiffness.

Rationale: Jimmy John presents with joint swelling and tenderness in addition to fever, malaise and a rash. These symptoms are consistent with clinical manifestations of new onset rheumatoid arthritis.

 

Differential Diagnosis II: Lyme Disease

Lyme disease is a tick-borne spirochete bacterial infection, and is a common arthropod-borne infection in the United States.  It affects all age groups and involves peripheral and central nervous systems.  Lyme disease is caused by the introduction of Borrelia burgdorferi  (Bb) via tick bite. Full transmission requires about 36 to 72 hours of attachment and feeding.  The microorganism is transferred from the gut of the tick into the skin of the host.  Bb larvae evade immune surveillance by inhibiting complement killing, producing surface protein that blocks phagocytic recognition.  Bb incubate for 3 to 32 days and then migrates to the skin, lymph nodes and other body systems (McCance & Huether, 2014).

Clinical Manifestations:

Stage 1 (Acute and Localized)

Within one month after the bite, the disease is characterized by a bull’s-eyes-like burning and expanding erythema migrans rash followed by general malaise, fever, muscle pain and headache.

Stage 2 (Systemic Infection)

Skin manifestation continues with or without acute widespread dissemination of antibodies and immune complexes and cardiac and neurologic involvement.

State 3 (Chronic Stage)

This stage may occur up to 2 years after the bite and involves arthritis and involvement of brain parenchyma with encephalitis, chronic neuropathy, and loss of cognitive deficit.

Rationale: Jimmy John presents with a rash that is similar to the bull’s-eye erythema migrans rash. He also has malaise, myalgia, and a fever. Lyme disease can also have cardiac involvement which is consistent with Jimmy John’s symptoms.

 

 

Differential Diagnosis III: Infective Endocarditis

Infective endocarditis is the infection and inflammation of the endocardium and the heart valves. Bacterial infections are the most common cause of infective endocarditis including streptococci, staphylococci, and enterococci. Other causes of endocarditis include viruses, fungi, rickettsia, and parasites (McCance & Huether, 2014).

There are 3 elements of the pathogenesis of endocarditis including:

• Endocardial Damage
• Blood-borne microorganism adherence to the damaged endocardial surface
  

  Endocarditis courtesy of http://www.rayur.com/bacterial-endocarditis-definition-causes-sign-symptoms-diagnosis-and-treatment.html

• Formation of infective endocardial vegetations

Clinical manifestations:

• Fever
• New or changed cardiac murmur
• Petechial lesions on the skin, conjunctiva
• Night sweats
• Weight loss
• Back pain
• Osler nodes (erythematous nodules on pads of fingers and toes)
• Janeway lesions (nonpainful hemorrhagic lesions on the palms and soles)

Rationale: Jimmy John has a new onset heart murmur which is a classic symptom of both rheumatic fever and infective endocarditis. In addition, the patient’s fever, rash, and diaphortic skin are consistent with clinical manifestations of infective endocarditis. Osler nodes can be mistaken for the subcutaneous nodes found in patients with rheumatic fever.