Mnemonic Based Approach to Joint Pain

Step 1: Arthralgia vs Arthritis

Arthralgia	Arthritis
Symptom	Diagnosis
Joint pain without inflammation	Joint pain with inflammation (swelling, redness, tenderness)
Articular or Non-articular	Articular

Articular	Non-articular
Pain with all joint ROMs	Pain with only some joint ROMs
Most painful at the limit of joint ROM	May not be most painful at the limit of joint ROM
All passive ROMs in joint reduced equally	1 or several passive ROMs reduced more than others
E.g. Arthralgia (Osteoarthritis, Articular fracture, AVN) or Arthritis	E.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 JOINT		Mnemonic: RAVINS
1. Septic arthritis	1. Oligoarticular JIA	1. Rheumatic fever
2. Internal derangement (Meniscal injury, ligament tears)	2. Reactive arthritis	2. Autoimmune – Seropositive: RA, SLE, Polymyositis, SS
3. Neuropathy (Charcot’s)	3. Psoriatic arthropathy	3. Autoimmune – Seronegative: Spondyloarthropathies
4. Gout, pseudogout and other crystal associated arthropathies		4. Vasculitis
5. Lyme disease		5. 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 arthritis		7. 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 articular	Non-inflammatory articular	Non-inflammatory non-articular
Warmth	Diffuse	Absent	Sometimes, local (e.g. bursa)
Swelling	Usually, diffuse	No; bony enlargement possible	Yes, at local structure
Redness	Septic arthritis and Crystal induced arthritis, diffuse	No	Rare, at local structure
Tenderness	Yes, over joint line	Yes, over joint line	Yes, over local structure
Stiffness	Morning, 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

Joints	Differential diagnoses
Symmetrical polyarticular MCP, PIP and MTP joints	RA, SLE, PsA, Polyarticular hout, ReA
DIP joint(s)	PsA, OA
Bony swellings of DIPs (Heberden’s node) or PIPs (Bouchard node) or 1st CMC joint	OA
Proximal girdle joints	Polymyalgia rheumatica, RA
Asymmetrical large joint oligoarticular disease	ReA, PsA, AS
Axial, sacroiliac and girdle joints	AS
Axial joints	Lumbar and cervical spondylosis/OA
Dactylitis (sausage digit)	PsA, ReA, AS, TB, Sarcoidosis, Sickle cell disease

Symmetrical	Asymmetrical
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), Lyme	Infectious: 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/Signs	Possible diagnosis
Rash	Erythema infectiosum (Slapped cheek, lacy rash)	Parvovirus B19
	Malar rash	SLE, Parvovirus B19, Lyme disease
	Plaque (scalp, navel, gluteal cleft)	PsA
	Heliotrope rash	Dermatomyositis
	Erythema chronicum migrans	Lyme arthritis
	Erythema marginatum	Rheumatic fever
	Erythema nodosum	Sarcoidosis, Crohn’s disease
	Pyoderma gangrenosum	IBD, RA, SLE, AS, Sarcoidosis, Wegener’s
	Palpable purpura	HSP, PAN, Hypersensitivity vasculitis
	Livedo reticularis	APLA syndrome, Vasculitis
	Keratoderma blenonorrhagicum	ReA, PsA
	Discoid rash	DLE, SLE, Sarcoidosis
	Gottron’s pauples or plaques	Dermatomyositis
	Vesicopustule or erythematous base	Gonococcal arthritis
Eyes
	Iritis or uveitis	Spondyloarthropathies, Sarcoidosis, Wegener’s
	Conjunctivitis	Spondyloarthropathies, SLE, Wegener’s
	Scleritis	RA, RPC
	Ischemic optic neuritis	Giant cell arteritis, Wegener’s
ENT
	Oral ulcers	SLE, Behcet’s syndrome, ReA, Wegener’s
	Parotid enlargement	Sjogren’s, Sarcoidosis
	Macroglossia	Amyloidosis
	Scalp tenderness	Giant cell arteritis
	Bloody or severe sinusitis	Wegener’s
	Inflammation of ear cartilage	RPC
Nails
	Onycholysis	PsA, Hyperthyroidism
	Pitting	PsA
	Clubbing	IBD, Whipple’s disease, Hyperthyroidism (thyroid acropachy)
Nodules
	Tophi	Gout
	Jaundice	Hepatitis, Hemochromatosis
	Hyperpigmentation	Whipple’s disease, Hemochromatosis
	Telangiectasia	Scleroderma
	Thickened skin	Scleroderma, Amyloidosis
Hair
	Thinning	Hypothyroidism, SLE

2. Others

Musculoskeletal
	Tender points	Fibromyalgia
	Heberden’s node and Bouchard’s node	OA
	Boutonniere and Swan neck deformities	RA, SLE, Ehlers-Danlos
	Dactylitis	Spondyloarthropathies
	Bursitis and enthesitis	Spondyloarthropathies
Constitutional
	Fever	Bacterial or viral infections, Still’s disease, SABE, Neoplasm
	Bradycardia	Hypothyroidism
Cardiovascular
	Mitral regurgitation and stenosis	Rheumatic fever
	Aortic regurgitation	AS, Rheumatic fever, RPC, ReA, Marfan’s, Takayasu arteritis
	Cardiomyopathies	Viral infection, Amyloidosis, Sarcoidosis, SLE, Polymyositis
	New murmur, fever	SABE, Rheumatic fever
	Diminished peripheral pulses	Giant cell arteritis, Takayasu’s arteritis
Respiratory
	PE, DVT	SLE, APLA syndrome
	Bronchial asthma	Churg-Strauss syndrome
Gastrointestinal
	Splenomegaly	Felty’s syndrome, Tumor associated arthritis
	Hepatomegaly	Hemochromatosis, Amyloidosis, Wilson’s disease, Whipple’s disease
	Jaundice	Viral Hepatitis
	IBD	Enteropathic arthritis
	HBV	Vasculitis
	HCV	Chronic HCV can present as RA
Genitourinary
	Prostatitis	ReA, AS
	Urethritis or cervicitis	ReA, Gonococcal arthritis
	Scrotal or vulval ulcers	Behcet’s syndrome
	Hypogonadism	Hemochromatosis
	Balanitis circinata	ReA
	Frothy urine, Hematuria	Lupus nephritis
	Still births	APLA syndrome
Neurologic
	Entrapment neuropathies	RA, Hypothyroidism
	Facial palsy	Lyme disease
	Peripheral neuropathy	SLE, amyloidosis
	Chorea	APLA syndrome, SLE, Rheumatic fever
	Mononeuritis multiplex	SLE
	Seizures	SLE
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 measures	Parameters	Interpretation
DAS28 CRP	Number 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
CDAI	TJC 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
SDAI	CDAI + 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