Mnemonic Based Approach to Joint Pain

Step 1: Arthralgia vs Arthritis

ArthralgiaArthritis
SymptomDiagnosis
Joint pain without inflammationJoint pain with inflammation (swelling, redness, tenderness)
Articular or Non-articularArticular
ArticularNon-articular
Pain with all joint ROMsPain with only some joint ROMs
Most painful at the limit of joint ROMMay not be most painful at the limit of joint ROM
All passive ROMs in joint reduced equally1 or several passive ROMs reduced more than others
E.g. Arthralgia (Osteoarthritis, Articular fracture, AVN) or ArthritisE.g. Arthralgia (Tendinitis, Bursitis, Enthesitis, Ligament problems, Muscle problems)

Step 2: Arthritis focused history

Mnemonic: NO PADS

a. Number of joints involved

Mono-articular (1)Oligo-articular (2-4)Polyarticular (5 or more)
Mnemonic: SINGLE JOINTMnemonic: RAVINS
1. Septic arthritis1. Oligoarticular JIA1. Rheumatic fever
2. Internal derangement (Meniscal injury, ligament tears)2. Reactive arthritis2. Autoimmune – Seropositive: RA, SLE, Polymyositis, SS
3. Neuropathy (Charcot’s)3. Psoriatic arthropathy3. Autoimmune – Seronegative: Spondyloarthropathies
4. Gout, pseudogout and other crystal associated arthropathies4. Vasculitis
5. Lyme disease5. Infiltrative: Sarcoidosis, Amyloidosis, Hemochromatosis, Tophaceous gout
6. Enteric and Erotic related arthritis (Reactive arthritis)6. Infective: Gonococcal, Spirochetal (Lyme, Syphilis), Viral (HIV, Hepatitis B, Parvovirus)
7. Juvenile Idiopathic arthritis and Rheumatoid arthritis7. Neoplastic (metastases) and paraneoplastic
8. Osteoarthritis, Osteomyelitis, Osteochondritis dissecans, Osteitis deformans (paget’s disease)8. Still disease (Systemic onset JIA)
9. Ischemic bone (Avascular necrosis)
10. Neoplasms (Osteoid osteoma, Pigmented villonodular synovitis, Bony metastases)
11. Trauma (Fractures, Overuse syndromes, Hemarthrosis)

b. Onset and duration

Acute: <6 weeks duration and Chronic: >6 weeks duration

Sudden (hours to few days) onset and Acute:

  • Septic arthritis
  • Acute rheumatic fever
  • Reactive arthritis
  • Crystal induced arthritis
  • Elderly onset rheumatoid arthritis

Gradual (weeks to months) onset and Chronic:

  • Other autoimmune inflammatory arthritis
  • Mycobacterial and fungal arthritis
  • Degenerative arthritis like OA
  • Neuropathic arthropathy (Charcot’s)
  • Tumors
  • Infiltrative disease

c. Pattern

  1. Additive: OA, Rheumatic diseases including RA
  2. Migratory: Rheumatic fever, Gonococcal arthritis, early Lyme arthritis, AML
  3. Intermittent: Crystal induced arthritis, Spondyloarthropathies, SLE, Sarcoidosis, RA

d. Activity’s effect and Inflammation

Inflammatory articularNon-inflammatory articularNon-inflammatory non-articular
WarmthDiffuseAbsentSometimes, local (e.g. bursa)
SwellingUsually, diffuseNo; bony enlargement possibleYes, at local structure
RednessSeptic arthritis and Crystal induced arthritis, diffuseNoRare, at local structure
TendernessYes, over joint lineYes, over joint lineYes, over local structure
StiffnessMorning, 30 minutes or more, stiffness after period of rest (gelling)Morning, <30 minutes; gelling <5-10 minutes

e. Age

Possible differential diagnoses in children with joint pain and swelling can be remembered using the mnemonic ARTHRITIS.

  1. Avascular necrosis and epiphyseal disorders (Perthe’s disease, SCFE)
  2. Reactive and postinfectious arthritis (Rheumatic fever)
  3. Trauma
  4. Hematologic (Leukemia, Bleeding disorders, Hemoglobinopathies)
  5. Rickets, metabolic and endocrine disorders
  6. Infection (Septic arthritis, Osteomyelitis, Lyme arthritis, Parvovirus associated arthritis)
  7. Tumor (Osteosarcoma, Lymphoma, Neuroblastoma)
  8. Idiopathic pain syndromes (CRPS1, Fibromyalgia)
  9. Systemic rheumatologic diseases (SLE, JIA)

f. Distribution

JointsDifferential diagnoses
Symmetrical polyarticular MCP, PIP and MTP jointsRA, SLE, PsA, Polyarticular hout, ReA
DIP joint(s)PsA, OA
Bony swellings of DIPs (Heberden’s node) or PIPs (Bouchard node) or 1st CMC jointOA
Proximal girdle jointsPolymyalgia rheumatica, RA
Asymmetrical large joint oligoarticular diseaseReA, PsA, AS
Axial, sacroiliac and girdle jointsAS
Axial jointsLumbar and cervical spondylosis/OA
Dactylitis (sausage digit)PsA, ReA, AS, TB, Sarcoidosis, Sickle cell disease
SymmetricalAsymmetrical
Inflammatory: RA, PsA, SLE, JIA (systemic and polyarticular types), adult onset Still’s disease, Sjögren’s syndrome; Other systemic rheumatic (SLE, MCTD, adult onset rheumatic fever, polymyalgia rheumatica, erosive inflammatory, osteoarthritis, pseudo-RA type CPPD disease)Inflammatory: ReA, PsA, Pauciarticular JIA, Oligoarticular or polyarticular gout, psedogout type CPPD disease
Infectious: Viral arthritis (Parvovirus), LymeInfectious: Bacterial arthritis, Bacterial endocarditis
Infiltrative: Sarcoid arthritis, Amyloid arthropathy, Hemochromatosis
Neoplastic: Leukemia, Chemotherapy induced
Endocrinal: Myxedematous arthropathy

g. Systemic or Extra-articular symptoms

  1. Skin and mucous membrane
Symptoms/SignsPossible diagnosis
RashErythema infectiosum (Slapped cheek, lacy rash)Parvovirus B19
Malar rashSLE, Parvovirus B19, Lyme disease
Plaque (scalp, navel, gluteal cleft)PsA
Heliotrope rashDermatomyositis
Erythema chronicum migransLyme arthritis
Erythema marginatumRheumatic fever
Erythema nodosumSarcoidosis, Crohn’s disease
Pyoderma gangrenosumIBD, RA, SLE, AS, Sarcoidosis, Wegener’s
Palpable purpuraHSP, PAN, Hypersensitivity vasculitis
Livedo reticularisAPLA syndrome, Vasculitis
Keratoderma blenonorrhagicumReA, PsA
Discoid rashDLE, SLE, Sarcoidosis
Gottron’s pauples or plaquesDermatomyositis
Vesicopustule or erythematous baseGonococcal arthritis
Eyes
Iritis or uveitisSpondyloarthropathies, Sarcoidosis, Wegener’s
ConjunctivitisSpondyloarthropathies, SLE, Wegener’s
ScleritisRA, RPC
Ischemic optic neuritisGiant cell arteritis, Wegener’s
ENT
Oral ulcersSLE, Behcet’s syndrome, ReA, Wegener’s
Parotid enlargementSjogren’s, Sarcoidosis
MacroglossiaAmyloidosis
Scalp tendernessGiant cell arteritis
Bloody or severe sinusitisWegener’s
Inflammation of ear cartilageRPC
Nails
OnycholysisPsA, Hyperthyroidism
PittingPsA
ClubbingIBD, Whipple’s disease, Hyperthyroidism (thyroid acropachy)
Nodules
TophiGout
JaundiceHepatitis, Hemochromatosis
HyperpigmentationWhipple’s disease, Hemochromatosis
TelangiectasiaScleroderma
Thickened skinScleroderma, Amyloidosis
Hair
ThinningHypothyroidism, SLE

2. Others

Musculoskeletal
Tender pointsFibromyalgia
Heberden’s node and Bouchard’s nodeOA
Boutonniere and Swan neck deformitiesRA, SLE, Ehlers-Danlos
DactylitisSpondyloarthropathies
Bursitis and enthesitisSpondyloarthropathies
Constitutional
FeverBacterial or viral infections, Still’s disease, SABE, Neoplasm
BradycardiaHypothyroidism
Cardiovascular
Mitral regurgitation and stenosisRheumatic fever
Aortic regurgitationAS, Rheumatic fever, RPC, ReA, Marfan’s, Takayasu arteritis
CardiomyopathiesViral infection, Amyloidosis, Sarcoidosis, SLE, Polymyositis
New murmur, feverSABE, Rheumatic fever
Diminished peripheral pulsesGiant cell arteritis, Takayasu’s arteritis
Respiratory
PE, DVTSLE, APLA syndrome
Bronchial asthmaChurg-Strauss syndrome
Gastrointestinal
SplenomegalyFelty’s syndrome, Tumor associated arthritis
HepatomegalyHemochromatosis, Amyloidosis, Wilson’s disease, Whipple’s disease
JaundiceViral Hepatitis
IBDEnteropathic arthritis
HBVVasculitis
HCVChronic HCV can present as RA
Genitourinary
ProstatitisReA, AS
Urethritis or cervicitisReA, Gonococcal arthritis
Scrotal or vulval ulcersBehcet’s syndrome
HypogonadismHemochromatosis
Balanitis circinataReA
Frothy urine, HematuriaLupus nephritis
Still birthsAPLA syndrome
Neurologic
Entrapment neuropathiesRA, Hypothyroidism
Facial palsyLyme disease
Peripheral neuropathySLE, amyloidosis
ChoreaAPLA syndrome, SLE, Rheumatic fever
Mononeuritis multiplexSLE
SeizuresSLE
Lymphadenoapthy
Tumor associated arthritis, SLE, Lymphoma with Sjogren’s syndrome

Step 3: Physical Examination

  1. General appearance and vital signs
  2. Head to toe examination (Look for systemic and extra-articular manifestations mentioned above)
  3. Specific joint examination (Look, Feel, Move, Special tests)
  4. Systemic examination – CNS, CVS, Chest, Abdomen (Look for systemic and extra-articular manifestations mentioned above)

Counting 28 Joints in Rheumatoid Arthritis

Mnemonic: SKEW 2F

  1. Shoulders (2)
  2. Knees (2)
  3. Elbow (2)
  4. Wrist (2)
  5. 2 joints in each Fingers – MCP and PIP/IP joints in 8 fingers and 2 thumbs (20)

Remission in Rheumatoid Arthritis

a. Boolean based definition

At any point of time, patient must satisfy all of the following:

  1. Tender joint count (TJC 28) </= 1
  2. Swollen joint count (SJC 28) </= 1
  3. CRP </= 1 mg/dl
  4. Patient global Assessment (PGA) </= 1 (on 0-10 scale)

b. Index based definition

Outcome measuresParametersInterpretation
DAS28 CRPNumber of tender joints (TJC 28)
Number of swollen joints (SJC 28)
ESR or CRP level
PGA
DAS28 CRP = 0.56*sqrt(TJC28) + 0.28*sqrt(SJC28) + 0.70*Ln(ESR) + 0.014*PGA

</= 2.6: Remission
2.6-3.2: Low disease activity
3.2-5.1: Moderate disease activity
>5.1: High disease activity
CDAITJC 28
SJC 28
PGA (0 to 10 scale)
Evaluator’s Global Assessment or EGA (0 to 10 scale)
CDAI = SJC + TJC + PGA + EGA

</= 2.8: Remission
2.8-10: Low disease activity
10-22: Moderate disease activity
>22: High disease activity
SDAICDAI + CRP level</= 3.3: Remission
3.3-11: Low disease activity
11-26: Moderate disease activity
>26: High disease activity

Symbols
RA: Rheumatoid Arthritis
JIA: Juvenile Idiopathic Arthritis
AS: Ankylosing Spondylitis
ReA: Reactive Arthritis
PsA: Psoriatic Arthritis
SABE: Subacute Bacterial Endocarditis
RPC: Relapsing Polychondritis
OA: Osteoarthritis
SLE: Systemic Lupus Erythematosus
APLA: Antiphospholipid Antibody
PAN: Polyarteritis Nodosa
HSP: Henoch Schonlein Purpura
IBD: Inflammatory Bowel Disease
DAS: Disease Activity Score
CDAI: Clinical Disease Activity Index
SDAI: Simple Disease Activity Index


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