a teaching method for rheumatology Simplifying rheumatologic diagnosis at the bedside AFLAR May 2011 Daniel Sager MD, FACR
introduction Rheumatology is often perceived by students to be a complex subject, and difficult to learn 1 Diseases may have: diverse and overlapping manifestations features similar to infection, malignancy, toxicities, or even psychosomatic disorders serious consequences
introduction (2)
Rheumatic complaints and diseases are a common part of medical practice2
>15% of visits to primary care physicians 6-10% of population may have chronic rheumatic disability
yet some rheumatic diseases are rare
introduction (3) Rheumatology is generally under-represented in medical education3  Novice learners use their limited experience in generating only one or two diagnostic hypotheses, often by recall of a past image  Diagnostic reasoning, and diagnostic success, is limited if the differential diagnosis is incomplete 
introduction (4) Although comprehensive content guidelines for rheumatologic diagnosis are available4, these do not include orientation of the student to the primary categories, or patterns, of disease  Clinical settings allow for little teaching time 
therefore 
A simplified classification system, to teach and to use at the bedside in the evaluation of patients with rheumatic disease, is needed
teaching rheumatologic diagnosis First, teach a simplified system to organize diagnostic possibilities (a menu)  Second, teach the clinical disease patterns  Third, teach diagnostic reasoning (deductive testing of hypotheses)5 
applying a logical sequence
the rheumatologic menu FIVE CATEGORIES
CTD Vasculitis Arthritis Non-articular pain Miscellan. 1 2 3 4 5
interviewing with a rheumatology menu Key to success usually involves simplification of complexity Classification schemes organize complex data “Layering” of knowledge, at a later stage, can be customized to the particular student and teaching environment using any effective teaching technique6,7
Carl Linnaeus (1707-1778) father of modern taxonomy
diagnosis is the central element in patient care Success of treatment is dependent on accuracy of diagnosis Patient compliance with treatment is based on agreement with physician’s diagnosis
The rheumatologic menu CTD
Vasculitis
ARTHRITIS Non-articular pain
Misc.
The rheumatologic menu CTD
Vasculitis
Arthritis
Non-articular pain
Misc.
connective tissue disease (CTD) 3 groups, each with 2 options SLE/Sjogren syndrome Polymyositis/Dermatomyositis Systemic sclerosis (scleroderma)
Diffuse
and rapidly progressive form Limited form (CREST), or localized form Overlap syndromes and differential diagnosis
SLE
AFTER recognizing the diagnostic pattern, look for ways to make the diagnosis complete (if needed) Diagnostic
criteria
Serology Biopsy Rule
out drug induced lupus Rule out mimics Expert opinion
The rheumatologic menu CTD
VASCULITIS
Arthritis
Other MS pain
Miscellan.
vasculitis 3 groups, defined by size of vessel involved
Large Medium Small
Medium and small vessel disease features and classification often overlap Beware: many mimics of vasculitis exist, and vasculitis is relatively uncommon
vasculitis: 3 groups, each with 2 options
Large vessel disease Giant
cell arteritis (GCA): age > 50 years at onset Takayasu arteritis: age < 50
Medium vessel disease Pulmonary-renal
syndromes (e.g. Wegener’s) Polyarteritis nodosa
Small vessel Specific
diseases Non-specific (antigenic) causes
small vessel vasculitis
Specific forms Henoch
Schonlein Purpura Mixed cryoglobulinemia: Hepatitis C
Nonspecific forms Drug Tumor Infection Autoimmune
(including CTDs and RA) Other or unknown cause
The rheumatologic menu CTD
Vasculitis
ARTHRITIS vs. Other MS pain
Miscellan.
“joint pain”: arthritis or not?
non-articular pain
Regional pain syndrome (tendon, bursa, muscle) Central pain syndrome (fibromyalgia, complex regional pain) Nerve (peripheral neuropathy, nerve root, cord) Referred (from viscera, spine, other) Internal joint derangement (meniscus, ligament) Bone (fracture, osteonecrosis, tumor, metastasis, other) Skin, fascia, pannus
arthritis or not?
History: 2 key questions “Point
to where you have pain” “What-where-when, otherwise”
Physical aspects of arthritis Localized pain on passive joint ROM (watching patient’s face) Joint-line tenderness > other tenderness Joint effusion or deformity
2 key questions for pattern recognition Point to where you hurt? Clarifies if the process is arthritis or not What else, where else, and when else? Clarifies if systemic illness features are present or not, or if other disease is present that may underlie the rheumatologic illness or influence treatment of it Clarifies if process is monoarticular or poly Clarifies if problem is truly “acute”
diagnosis is based on pattern recognition
Diagnosis is formed with the HPI8 HPI
must be more than an inventory of problems Clinical reasoning skills form the foundation for effective doctoring9
Diagnosis is tested with the physical exam Systematically
(adds 5% to case finding)10 Reflexively, to test hypotheses generated11
Diagnosis is confirmed primarily by excluding alternatives, observing over time, and, only occasionally, with laboratory tests or imaging
steps in “intentional interviewing” Keep diagnostic categories (menu) in mind Index of suspicion: for common and serious problems Key questions for pattern recognition Recognizing the pace of illness Rheumatologic Review of Systems Determining the pre-test probability of disease
pace of illness as clue to diagnosis
Episodic/progressive? Lupus Crystal
arthritis
Acute/emergent? Infection;
Subacute/additive? CTD;
Giant cell arteritis; transverse myelitis
Polymyalgia rheumatica/vasculitis; RA
Chronic/progressive? Osteoarthritis;
fibromyalgia
acute arthritis Patient complains of “joint” pain Step 1: arthritis or not?
Step 2: acute or chronic?
Acute arthritis Infection (bacterial, viral, reactive) or Crystal associated arthritis and differential dx: Sarcoidosis (Lofgren syndrome) Early chronic arthritis (e.g very early RA) other
chronic arthritis Step 1: arthritis or not? Step 2: acute or chronic arthritis?
Step 3: inflammatory arthritis or not? Chronic
inflammatory arthritis: Rheumatoid arthritis or spondyloarthropathy Chronic non-inflammatory arthritis: Primary or secondary osteoarthritis, hemarthrosis, hemochromatosis, other
inflammatory arthritis pattern Stiffness syndromes (> pain, weakness) AM stiffness prominent and prolonged Worse with inactivity Signs: heat, swelling, tenderness, redness Acute phase reactants Beware: nonspecific or variable features
Step 4: RA versus Spondyloarthropathy
Polyarthritis UE predilection Ø back/DIP Extensor tenosynovia Scleritis Nodules, Sjogren’s ANA, RF, CCP Age at onset: any
Mono/oligoarticular LE predilection + back/DIP joint Enthesitis Uveitis Psoriasis, colitis, urethritis, stomatitis HLA B27 Age at onset: early
the diagnostic pattern of RA S1 (Six weeks) S2 (Synovitis) S3 (Several swollen joints) S4 (Symmetric) S5 (Small joints)
Chronic Inflammatory Polyarthritis
Bilateral, in wrists and/or MCP joints
RA pattern and differential dx Severe Chronic Inflammatory Polyarticular Arthritis Idiopathic
Rules out most cases of: celiac disease parvovirus B19 osteoarthritis TB/Lyme fibromyalgia/other crystal arthritis
how are you sure it is RA?
AFTER identifying the pattern, look for ways to make the diagnosis complete Diagnostic criteria (90% specificity) Serology (Anti-CCP antibody: 90% spec.) Rheumatoid nodule Radiographs (typical erosions: not early in course, and only in 70% of patients overall) Rule out mimics Expert opinion
spondyloarthropathies Ankylosing spondylitis or psoriatic arthritis ď&#x201A;¨ Reactive arthritis (+/- inflammatory bowel disease or chlamydia) ď&#x201A;¨
Differential diagnosis may include: sarcoidosis atypical infection atypical RA or CTD chronic stage of gout/pseudogout
The rheumatologic menu CTD
Vasculitis
Arthritis
Other MS pain
MISCELLAN.
miscellaneous disorders associated with rheumatic features (examples)
Fever-mucocutaneous syndromes: e.g. Still’s, Behcet’s, sarcoidosis Endocrine/metabolic/deposition diseases: thyroid/PTH, acromegaly, diabetes, renal Malignancy/paraneoplastic syndromes Hematologic disease: sickle cell, leukemia HIV syndromes Drug/toxin exposure Hereditary/neurologic syndromes
teaching rheumatologic diagnosis First, teach the menu (schematic) structure Second, teach the clinical disease patterns Third, teach diagnostic reasoning
Heuristics Bayes’
Theorem
diagnostic reasoning: examples
Heuristics (general guiding rules in science) “What’s common is common” (“Hear hoof beats? Think horses, not zebras”) Sutton’s law Uncommon manifestation of common disease > common manifestation of uncommon disease “Push, shove, or squeeze, give the patient one disease” Occam’s razor (law of parsimony) “You have what you have”
using Bayes’ Theorem in diagnosis
Pre-test probability of diagnosis determines performance of test (post-test probability) i.e. epidemiology and the patient’s disease characteristics (pre-test probability), if calculated accurately by clinician, are critical in interpreting test sensitivity and specificity (and the “result”)
A teaching method for rheumatologic diagnosis Summary ď&#x201A;¨ Approach patient with a simplified classification scheme (a menu) in hand ď&#x201A;¨ Ask key questions and perform exam to find the predominating pattern ď&#x201A;¨ Use bedside diagnostic reasoning to determine pre-test probability of a disease before applying tests
the rheumatologic menu FIVE CATEGORIES
CTD Vasculitis Arthritis Non-articular pain Miscellan. 1 2 3 4 5 SLE/sjog Large PM/DM Medium dSScl/lSScl Small
Acute/chronic Inflamm/non-inflamm RA/spondylo
references 1
Clawson. It’s past time to reform the musculoskeletal curriculum. Acad Med 2001;76:709 Woolf. Burden of major musculoskeletal conditions. Bull World Health Organ 2003;81:646 Rasker. Rheumatology in general practice. Br J Rheumatol 1995;34:494 Woolf. History and physical exam. Best Prac Res 2003;17:381
references 2
Elstein. Heuristics and biases: selected errors in clinical reasoning. Acad Med 1999;74:791 Wolpaw. Using SNAPPS to facilitate the expression of clinical reasoning and uncertainties. Acad Med 2009;84:517 Irby. Teaching and learning in ambulatory settings: a thematic review of the literature. Acad Med 1995;70:898 Gruppen. Medical student use of history and exam in diagnostic reasoning. Arth Care Res 1993;6:64
references 3
Alexander. Moving students beyond an organbased approach when teaching medical interviewing and exam skills. Acad Med 2008; 83:906 Boland. Review of systems, physical examination, and routine tests for case-finding in ambulatory patients. Am J Med Sci 1995;309:194 Benbassat. Suggestions for a shift in teaching clinical skills to medical students: the reflexive clinical examination. Acad Med 2005;80:1121