Welcome to CUGH’s bi-weekly clinical case-series, “Reasoning without Resources,” by... Gerald Paccione of the Albert Einstein College of Medicine. These... Introduction:

Introduction:
Welcome to CUGH’s bi-weekly clinical case-series, “Reasoning without Resources,” by Prof.
Gerald Paccione of the Albert Einstein College of Medicine. These teaching cases are based on
Prof. Paccione’s decades of teaching experience on the medical wards of Kisoro District Hospital
in Uganda. They are designed for those practicing in low resource settings, Medicine and Family
Medicine residents, and senior medical students interested in clinical global health. Each case is
presented in two parts. First comes a case vignette (presenting symptoms, history, basic lab and
physical exam findings) along with 6-10 discussion questions that direct clinical reasoning
and/or highlight diagnostic issues. Two weeks later CUGH will post detailed instructors notes for
the case along with a new case vignette. For a more detailed overview to this case-series and the
teaching philosophy behind it, see Introduction to “Reasoning without Resources”. Comments or
question may be sent to Prof. Paccione at: gpaccion@montefiore.org
Note: If you would like to be notified when a new case is posted (along with instructor notes for
the previous one), send your e-mail to Jillian Morgan at jmorgan@CUGH.org
About the Author:
Dr. Gerald Paccione is a Professor of Clinical Medicine at the Albert Einstein College of
Medicine in the Bronx, New York. His career has centered on medical education for the past 35
years – as a residency Program Director in Primary Care and Social Internal Medicine at
Montefiore Hospital, and director of the Global Health Education Alliance at the school. He has
served on the Boards of Directors of Doctors for Global Health, Doctors of the World USA, and
the Global Health Education Consortium. Dr. Paccione spends about 3 months a year in Uganda
working on the Medicine wards of Kisoro District Hospital where he draws examples for the
case studies.
Gerald Paccione, MD
Professor of Clinical Medicine
Albert Einstein College of Medicine
110 East 210 St., Bronx, NY 10467
Tel: 718-920-6738
Email: gpaccion@montefiore.org
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CASE 9 – BACK PAIN
A 24 year old man, a farmer, was in his usual, fully functional state of health until 3 months ago
when he began feeling pain in his lower back and buttocks. The pain would begin at night during
sleep, be worse in the morning before going to the fields, and seem better by mid-day. At first, he
could dig the rest of the day without problems, but over the past 2 months the pain has gotten
gradually worse and he’s felt “hot” and increasingly weak. Getting up and walking around at
night helps lessen the pain in the morning. Sometimes the pain is worse in the right buttocks,
sometimes in the left. He tried aspirin, which provided some relief, but despite taking more
aspirin the pain has increased over the past few weeks such that it’s now too painful to walk at
all, and he’s had to stop working.
He’s had no other problems like this before, nor has anyone in his family, and no recent rashes,
joint swelling or pain, weight loss, abdominal pain, diarrhea, cough or lung problems, weakness
in his legs or arms, or problems with his urine. He’s been sexually active with his wife of 3
years, and over the past year when in Kampala with 3 other women, but has not had any
sexually-transmitted diseases nor noted a penile discharge. He’s not had any problems with his
vision, and he has had only1 episode of “red eyes” (with yellow crusts sealing his eyes in the
morning) about 4 months ago, which lasted 2 weeks and went away without treatment (neither
wife nor his 2 children had red eye at the time).
P.E. Well-nourished muscular young man, walking slowly supported by 2 other men, one on
either side.
V.S. T: 99 p.o.; BP 100/70; HR 88 and regular; R: 16
Skin/palms/soles: without rash or lesions
Eyes: not injected, PERRLA, no photophobia; fundi, normal with flat discs and no exudates
Mouth: no thrush or ulcers
Neck: no adenopathy, JVP, or thyromegaly
Lungs: clear
Heart: S1, S2, no murmurs or rubs;
Abdomen: no hepato-splenomegaly or tenderness, masses;
Rectal: guiuac (-), prostate palpable and soft/boggy, non-tender;
Musculo-skeletal: peripheral joints normal, with full range of motion; hands normal without
swelling; hips: normal internal and external rotation without pain for the first 30 degrees but
pain elicited at the extremes of motion in the buttocks and back bilaterally; palpation: tender to
firm palpation with thumb 2-3 cm to right and left of lower LS spine, 3-6 cm below level of
iliac crest pelvic compression at iliac crests bilaterally with patient supine: pain in mid-lower
back
Neurologic: normal mental status, sensory, reflexes, cerebellar; motor normal 5/5 upper
extremities, ~ normal motor lower extremities if no/minimal movement during
quadriceps/hamstring/psoas evaluations; gait: limited by pain, clutching lower back.
U/A (post prostate exam): s.g. 1.025, protein -, blood +2, leuk est +2, nitrates (-), WBC 15-20,
RBC 10-20, no casts seen;
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INSTRUCTOR NOTES
What is the “frame” in this case (key clinical features the final diagnosis must be consistent
with)?
Young male, 24 years old
Timing of pain: Insidious onset, chronic, progressive over 3 months
Worse in the morning (after rest), better with exercise
Pain/difficulty with walking/weight bearing
Exam with palpation tenderness lateral to sacrum bilaterally; hip, normal internal/external rotation
As with most diagnostic challenges in Medicine there are 2 “levels” of the differential diagnosis in
this case: what and where is the pathology, and what’s causing it?
What pathologic process is causing this patient’s pain? How do you know?
Causes of low back pain (LBP), a very common problem in all populations, are customarily divided
into “mechanical” and “inflammatory”.
Over 95% of LBP is mechanical: stress/tear of ligaments, facets, or discs - usually characterized by
sudden onset, relief by rest or lying supine, worsened by movement or physical work, and transient,
with steady improvement over days/weeks.
Inflammatory pain is characterized by: insidious onset, gradual improvement with exercise and not
rest, and worse at night and in the morning. This patient has inflammatory pain.
Where does the pain originate from in this patient? How do you know?
The pain originates in the sacroiliac joints between the pelvis and the sacrum.
Sacroiliac pain is often vague and diffuse, felt across the lower back and in the buttocks, aggravated
by weight-bearing. Walking is painful, and often only possible with bilateral support. Although gait
can be affected in “mechanical” causes of LBP by muscle spasm or sciatic nerve impingement,
standing/weight-bearing in these other more common conditions is relatively painless.
In this patient, pain was felt in the buttocks bilaterally, frequently alternating in severity between
sides. Firm palpation over the SI joints elicited tenderness, as did medial compression of the pelvis at
the iliac crests which elicited pain over the compressed (inflamed) SI synchondrosis.
Internal and external rotation of the hips were normal up to the extremes of movement (which torques
the SI joints), signifying non-inflamed hips.
What other exam maneuvers can help localize the origin of LBP to this area?
Have patient lie on his side with lower leg extended and top leg flexed at both the hip and the knee 90
degrees: with the palm of your hand, jab the flexed kneecap in the direction of the femur. If the SI joint
is inflamed, sudden pain should be felt in the mid-back.
Have the patient lie supine with hip and knee again flexed 90 degrees: press down over the kneecap
with force. If the SI joint is inflamed, pain should be felt in the mid-back.
Have the patient lie prone: If the SI joint is inflamed, pressure on the lower spine should induce pain
over the SI joints.
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With the patient lying prone, hold the pelvis at the iliac crests bilaterally, and with alternating
movements, vertically lift and press down each side in a rocking sequence. If the SI joint is inflamed,
pain should be localized to the SI joint area.
What are the most common misdiagnoses made by novice diagnosticians in this type of
presentation?
Hip arthritis: especially if unilateral, sacroiliitis is often misdiagnosed as “hip arthritis” (possibly
septic hip arthritis if the patient is young) due to its vague localization around the back-buttock-hip
and the inability to weight bear;
Mechanical back pain/herniated disc: common things are common, farmers who bend, carry and dig
all day can have back pain, and most novice clinicians have never seen full-blown sacroiliitis. So
conflicting data is either not elicited (e.g. close-ended questions used and misinterpreted, appropriate
exam maneuvers not done) or the unexpected is ignored because it’s too dissonant.
“Forcing” diagnoses into familiar patterns and distorting observations to fit the known or
comfortable is a common cognitive error.
Thus, at the end of the history and physical exam, we conclude that this patient has a chronic
bilateral inflammatory sacroiliitis.
What is the differential diagnosis of this condition in the West (i.e. specific etiologies)?
How does the differential differ between the developed “West” and Sub-Saharan Africa?
In both the U.S. and Africa this patient would be considered to have the axial version (i.e. sacroiliitis,
SI) of the “spondyloarthritis” (SpA) family of diseases, which share certain clinical features: namely,
inflammation of the axial joints (SI), asymmetric oligoarthritis, and enthesitis (inflammation of the
ligamentous or tendon attachment to bone), with possibly additional extraarticular manifestations in
the eye, skin, genitals, and gut.
In the West, the relevant family of diseases that causes sacroiliitis bears a strong association with
(HLA) B27. It’s comprised of the following diagnoses:
Undifferentiated spondyloarthritis (USpA)
Ankylosing spondylitis (AS)
Reactive arthritis (ReA) (formerly Reiter syndrome)
SpA associated with Psoriasis
SpA associated with Inflammatory Bowel Disease (Crohn and ulcerative colitis)
Juvenile onset spondyloarthritis
The estimated prevalence of SpA in a Caucasian population is 0.5-2%, with the vast majority
being classified as USpA or ankylosing spondylitis.
The term USpA is used to refer to patients with inflammatory back pain who do not meet the
more specific criteria of the other disease subsets in the SpA family, e.g. not ankylosing spondylitis
because of the absence of radiologic evidence for AS; not ReA because of the absence of a definite
infection causing diarrhea or urethritis within 4 weeks before the arthritis developed).
Reactive arthritis (prevalence of 0.1% in the West, much less frequent than AS or USpA) is
thought to be an immune-mediated synovitis from slow bacterial infections that remain viable but
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elusive, and produce antigens that cause persistent inflammation. There are over 30 microbes
implicated but the best-defined agents of ReA are Chlamydia trachomatous urethritis (and
pneumonia), and the bowel pathogens salmonella, campylobacter, shigella, and yersinia. The HLA
B27 allele is thought to confer increased propensity for microbe survival in the synovium and
elsewhere, and/or for ongoing inflammation in the synovium.
The literature is confusing because the diseases are overlapping, long-term follow-up often
leads to more specific diagnoses as other manifestations appear, 30-40% of infections associated with
Reactive Arthritis are asymptomatic, and the list of causative organisms implicated in ReA continues
to grow and can’t be reasonably investigated anywhere.
In Africa, the differential diagnosis of SpA is influenced by the following observations:
a) HLA B27 is almost non-existent, and consequently ankylosing spondylitis and reactive
arthritis with extraarticular manifestations (Reiter syndrome) were thought to be rare (although
perhaps not as rare as clinical research in Africa!);
b) HIV has changed that: reactive arthritis and USpA, although often atypical, are now
commonly found in areas affected by HIV. In the absence of HLA B27, HIV may serve to either
facilitate microbe persistence and/or ongoing inflammation in inducing a “reactive arthritis”, or be
the cause of the ReA itself;
c) other infections endemic in Africa can cause chronic inflammatory disease of the SI joint
in young people, particularly TB and Brucella.
d) lack of diagnostic tests and X-rays make the application of Western diagnostic criteria for
the various forms of SpA that much more difficult.
What are the most useful diagnostic clinical criteria to apply to this condition in Africa?
The European Spondyloarthritis Study Group’s (ESSG) are clinical, and do not rely on tests, like HLA
B27 or MRI/X-rays that are unavailable in Africa.
According to the ESSG criteria, to be classified with SpA, a patient has to satisfy
ONE of two entry criteria: “inflammatory” back pain (i.e. 4 of 5 of: age of onset <40, insidious onset,
chronic for >3 months, morning stiffness, improvement with exercise) OR synovitis that is either
asymmetric or predominantly in the legs (warm, swollen soft tissue, effusion, decreased active and
passive range of motion, worse after rest).
PLUS ONE additional criterion: (+) family history; urethritis, cervicitis, or acute diarrhea within one
month before arthritis; buttock pain alternating between buttocks; enthesopathy; psoriasis;
inflammatory bowel disease; X-ray sacroiliitis.
The Amor criteria add “points” for other clinical features: sausage-like toe or digit, heel pain,
iritis, response to NSAIDS within 48 hours or recurrence within 48 hours of discontinuation.
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What common diseases are eliminated from diagnostic consideration in this case by the timing
criteria, i.e. chronicity and onset of disease?
How frequently are the various clinical features associated with this disorder actually seen in
patients with it?
(N.B. Sensitivity (Se), % patients with SpA with the finding;
Specificity (Sp), % of non-SpA without the finding;
Likelihood ratio (LR), odds that a given test result came from someone with as opposed to without SpA)
The chronicity and onset criteria exclude from the differential diagnosis of SpA other causes of
infectious arthritis or sacroiliitis such as pyogenic staph infections (in IVDUs), gonococcal arthritis,
viral arthritides, and most spirochetal/borrelial infections.
As diagnostic tests, the accuracy of the various clinical features seen in chronic back pain due
to SpA are: (Data from Rudwaleit, M, et al AnnRheum Dis 2006; 65:1251-2; and Amor, B Rheum DisClin of N.Am
1998 24: 677-695)
Inflammatory type of back pain: Se 75%; Sp 76%; LR+ 3.1, LR- 0.33
Asymmetric oligoarthritis of lower limbs: Se: 40-45%, Sp: 85-95%, LR+4, LR- .67
Sausage Digit (dactylitis: tendinitis of finger): Se 20-25%, Sp 95-99, LR+ 4.5;
Heel pain (enthesitis, swelling on sides of Achilles tendon): Se 30-40%, Sp 90%, LR+3.4
Eye: Conjunctivitis: Se, 35%; iritis: Se, 5-20%, Sp 97%; LR+ 7.3, LR- 0.8
(+) F.Hx. for similar issues: Se 30%, Sp 95%; LR+6.4, LR- 0.7
Skin: keratoderma b. Se 5-30%; circinate balanitis Se 20-40%; oral ulcers (painless) Se 5-10%;
ESR elevated: Se 50%, Sp 80%, LR+2.5, LR- 0.6
Response to NSAIDS within 48 hrs: Se 75-80%, Sp 85%; LR+ 5.1, LR- 0.27
How would you diagnose/classify his illness? Explain.
What is the significance of him being African?
This patient has chronic sacroiliitis. By ESSG criteria, he meets one entry criteria for SpA,
inflammatory type back pain (5 of 5 items), and one additional criterion, bilateral buttuck pain. He fits
no additional criteria for a more specific diagnosis at this time, so his disease would be classified
USpA at this point.
Of note, his prostate is soft and boggy, and his urinalysis is abnormal: prostatitis is commonly seen in
reactive arthritis due to Chlamydia (80%), and even as part of the general immune response in ReA
due to enteric organisms, but is not one of the official “criteria” for SpA nor ReA. Neither is a history
of “conjunctivitis”, which this patient had (by history) around the time of the onset of back pain, a
criterion for SpA. Although conjunctivitis is common in ReA, it’s too non-specific to carry much
diagnostic weight (despite, in his case, no one else in his family having “red-eye” at the time, a very
contagious disease when due to common infection). Iritis, on the other hand, is a ReA/SpA criterion
due to its greater specificity.
This case illustrates a good example of why criteria created for and useful in research, may not
translate clinically: these features of this patient’s history, although suggestive of ReA, don’t count
“officially”.
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Although an X-ray of the SI joints may be possible in rural Africa, it’s unlikely to be abnormal: it takes
years of inflammation to show evidence of SI on a plain X-ray.
It’s most likely that this man has a form of reactive arthritis presenting as an axial SpA that we cannot
further specify etiologically for lack of advanced tests e.g. synovial culture or PCR identification of
organisms – with one exception: HIV, for which we can test.
Although this patient could have acquired Chlamydia during his sexual exploits in Kampala, it’s also
quite possible that he acquired HIV. The rarity of HLA B27 in Africans makes it more likely that HIV
is present, either facilitating the progression of chlamydial disease to ReA or itself causing the ReA
symptoms. (In Caucasions, Chlamydia induces ReA in only ~ 1-5% of cases (of Chlamydial infection),
and HLA B27 is the major risk factor.)
TB, Brucella and typhoid, all more commonly seen in Africa, are unlikely to be causing sacroiliitis in
this patient. All of these infections would usually be associated with significant additional symptoms
(e.g. fever, weight loss and possibly cough) often antedating the back pain, and the associated
sacroiliitis would likely be unilateral. Although late-stage HIV also causes constitutional symptoms
and wasting, the immune manifestations of HIV commonly occur before this, and indeed symptoms of
ReA often resolve as the disease progresses.
What further diagnostic tests would be warranted in this patient in rural Africa?
HIV
Empiric trial of NSAIDS (can be used as a diagnostic test for SpA, and therapy)
Plain film of SI joint: unlikely to be abnormal or to change diagnostic impression
ESR: unlikely to influence diagnosis (risk is that it will be misinterpreted as indicating no SpA if
normal (50% chance))
What is the appropriate treatment and prognosis for this patient?
Therapy in chronic SpA has been disappointing, and in Africa is largely restricted to NSAIDs.
Although persistent microbial antigens or organisms are thought to be the basis of ReA, antibiotic
therapy has been disappointing: it doesn’t work in enteric ReA, nor in chronic urogenital ReA.
In acute urogenital ReA (i.e. the first presentation of arthritis within the past 6 months, with initial
onset of disease within 4 weeks of urethritis) anti-chlamydial antibiotics decrease the duration of
symptoms and the likelihood of recurrent arthritis, although do not influence long-term prognosis.
Since this patient did not have defined urethritis, he does not exactly fit that picture. Nevertheless,
treatment of both he and his sexual contacts for Chlamydia makes good public health sense, and
prolonged therapy (for acute chlamydial ReA) could be warranted despite the paucity of evidence that
it will help his sacroiliitis. If the patient is HIV+, consideration should be given to treating HIV
independent of his CD4 count if NSAIDs are insufficient to control the activity of the sacroiliitis.
Prognosis is very difficult to assess in SpA with its multiple etiologies and overlapping syndromic
classifications. In general, 30-50% recover, 20-40% recur, and 30-50% develop chronic disease or
symptoms. Reactive arthritis in patients with HIV tends to run a more aggressive course with
extraarticular manifestations, but the data are sparse.
Our patient was HIV (+).
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Suggested Readings:
Rudwaleit, M. et al; Easy assessment of axial spondyloarthritis (early ankylosing spondylitis) at the
bedside Ann Rheum Dis 2006; 65:1251-12
Njobvu P, McGill, P; Human Immunodeficiency Virus Related Reactive Arthritis in Zambia J
Rheumatol 2005; 32:1299-304
Colmegna, I; et al. HLA-B-27-Assocaiated Reactive Arthritis: Pathogenetic and Clinical
Considerations Clinical Microbiol Rev 2004; 17(2):348 – 360
Carter, J.D., et al. Chlamydiae as Etiologic Agents for Chronic Undifferentiated Spondyloarthritis
Atrhitis Rheum. 2009; 60 (5): 1311-16
UpToDate; Yu, D.T. Undifferentiated spondyloarthritis: Clinical Manifestations, definition and
diagnosis
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CASE_9_Back_Pain_INSTRUCTOR_NOTES_FINAL
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