Bull's Eye!

   In late August a twenty-five-year-old Caucasian male presents at the Emergency Room with joint pain of his extremities. His pain is in both of his knees and his left elbow. He explains that the pains have been jumping from one joint to the other for the past week despite his use of aspirin.

Question 1 - Single Best Answer

What two mechanisms can cause stiff and sore joints?   

A) infectious and mechanical
B) infectious and reactive
C) immunological and reactive
D) infectious and neoplastic
E) toxic and infectious

Upon taking a detailed history of the patient you learn that the previous spring he worked as a trail guide at a campground in Bath, Connecticut. He ended his work there in June to start summer school at a local community college.

He recalled having several of what he believed were insect bites below his right knee, but ignored them. However, over the next week the irritation became worse, with the affected area spreading above and below the knee. He assumed that the bites had become infected, or that he had brushed a poisonous plant. He treated the area with a topical antibiotic, 0.5% Hydrocortisone cream, and calamine lotion. The rash was unusual in that the outer edges were raised, and of a deeper red color than it's interior. It resembled a bull's eye.

Question 2 - Single Best Answer

What are some diseases that can be spread by an insect bite? (Note: Most people, if bitten by a tick, would say they had an insect bite. This is not theoretically correct as the tick is an arthropod, not an insect. For this question consider both insects and ticks.)   

A) malaria
B) equine encephalitis
C) Lyme disease
D) Rocky Mt. spotted fever
E) all of the above

Question 3 - Single Best Answer

The unusual lesion above and below his knee is known as?   

A) petechia
B) secondary syphilis
C) erythema chronicum migrans
D) cellulitis
E) scalded skin syndrome

Question 4 - Single Best Answer

What is the cause of the erythema chronicum migrans or ECM?   

A) trauma to the site
B) a hypersensitivity reaction to a fire ant bite
C) a bite by a tick carrying Borrelia burgdorferi at the site of the ECM
D) contact with a rabbit infected with Francisella tularensis
E) contact with a spore of Bacillus anthracis

Over a period of three weeks the rash slowly disappeared. Afterwards he began to feel lethargic, with little energy to perform even simple tasks. Even in the air conditioned classroom he felt unusually warm and fatigued. He also had frequent headaches and nausea. He could not concentrate on class work or on any household chores. Sleep was difficult and restless. For a period of two days he had a swollen right eye, and poor peripheral vision. Then all of these symptoms disappeared.

Question 5 - Single Best Answer

Were these symptoms (lethargy, headaches, lack of concentration) related to the ECM ?   

A) yes, definitely
B) no, definitely not
C) perhaps - but there are a lot of things that can cause similar symptoms.

Towards the end of August, after he had been feeling quite well for over a month, he developed pain in the right knee which disappeared with the use of aspirin. Several days later he experienced pain and swelling in both knees and his left elbow, at which time he decided to visit the Emergency Room.

Question 6 - Single Best Answer

Do you think that his present problem is related to his earlier systemic problem?   

A) Yes, absolutely. There could be no other explanation.
B) Yes, perhaps. But not necessarily.
C) It is improbable - but not impossible.
D) No, absolutely not. There couldn't be any relation.

Question 7 - Single Best Answer

Which of the following things would you most like to ask him now?   

A) history of sexually transmitted diseases
B) neoplastic diseases in his family
C) recent outdoor activities
D) recent contact with animals
E) recent travel to foreign countries

He denied a history of rheumatic fever/disorder. He had just acquired a new girlfriend with whom he had several sexual encounters. He had not ever contracted syphilis or any other sexually transmitted diseases that he knew of. He denied the use of illegal drugs, occasionally smoked cigars, but he did admit to moderate to heavy use of alcohol, particularly since he met his new girlfriend and it helped him get over his shyness with her.

Question 8 - Single Best Answer

The mechanism by which Neisseria gonorrhoea causes joint problems is?   

A) by causing an active infection of the joint
B) by stimulating antibodies that react with the joint capsule
C) its endotoxin stimulates TNF which causes joint degeneration.
D) it is not known

Upon physical examination you found that both knees and the left elbow were very tender and slightly swollen. Joint movement was only moderately restricted. There was evidence of fluid in the left knee joint. His throat was not sore, nor did it appear to be inflamed. No sores were visible on his penis, nor was there a purulent discharge. Auscultation revealed no rubs or murmurs from his heart. You then took laboratory samples of blood and synovial fluid and also a urethral swab.

Question 9 - Single Best Answer

Does the lack of a purulent discharge mean he doesn't have gonorrhea?   

A) yes, infection with N.G is always symptomatic
B) no, infection with N.G. can be inapparent.

The patient was placed on a regimen of ibuprofen to relieve pain and swelling until further lab results were available. He was sent home until then.

Question 10 - Single Best Answer

The fact that no bacteria grew from his joint fluid means that?   

A) the cause is not Neisseria gonorrhea
B) the cause is Treponema pallidum because it has never been grown in the laboratory.
C) the cause will never be known if the organism doesn't grow
D) further tests are in order
E) more than one of the above is correct.

Question 11 - Single Best Answer

What further test(s) would you do now?   

A) VDRL
B) antibodies to B. burgdorferi
C) FTA-abs
D) blood smear
E) all of the above

The results showed the following:

Question 12 - Single Best Answer

How could the VDRL be positive and the TPA-abs be negative?   

A) he had congenital syphilis which gives a negative TPA-abs
B) his Lyme disease was causing the positive VDRL
C) the lab made a mistake
D) he has tertiary syphilis and there are no antibodies present at this stage.
E) the Lyme disease was interfering with the TPA-abs

The patient was contacted and recalled to the outpatient clinic where he was told he had Lyme disease and was instructed to continue his use of ibuprofen. He was placed on an antibiotic regimen of oral doxycycline at 100 mg for six weeks. His pain remained for some time afterwards but he did not develop further swelling or joint pain.

Question 13 - Single Best Answer

Which are common sequelae of B. burgdorferi infection?   

A) neurological disorders, brain abscesses
B) chronic fatigue, myalgia, axillary abscess
C) meningitis, myocarditis
D) neurologic disorders, arthralgia, chronic fatigue, myocarditis
E) myocarditis, myalgia, brain abscesses

Question 14 - Single Best Answer

The stages of Lyme Disease are reminiscent of which other disease?   

A) plague
B) meningitis
C) myasthenia gravis
D) syphilis
E) toxic shock syndrome