 \200 \200 Symmetry The vast majority of people start off life broadly symmetrical (left to right)! De velopment of dominant right- or left- sided function can change symmetry slightly, and cert ainly previous disease or injury can lead to obvious asymmetry. Examining both sides when p resented with unilateral loco- motor symptoms is important to orientate the examiner as to what is \200\230normal \200\231 for the person being examined. Important examples include: \200 Shoulder movement range. Subtle degrees of shoul- der restriction can accompany rotator cuf f lesions. There is, however, a variation in normal shoulder movements in the population. I t is always important to examine a patient \200\231s good shoulder \201 rst. Subtle degre es of loss of knee joint movement can be missed. It within the accepted \200\230normal \200\231 range to have a little extension at the knee. The conclusion that a \200\231fully straight \200\231 knee on the couch is normal would therefore be erroneous, without testing for extension in the symp- tomatic and unaffected knee. Similarly, given that early loss o f hip movement is often only appreciated from restriction of hip extension, it is important to examine patients with hip symptoms while \200 CHAPTER 1 Clinical assessment of rheumatological disease 9 How (whether) is your hand is shaken. Does the patient sit skew (?unilateral back/hip pain) ? they are lying prone. Extension range of the hip, how- ever, is sometimes hard to interpret given the tendency for additional pelvis tilt and back arching when the leg is lifted. Com pare sides. Gait Antalgic A limp can be obvious and accentuates the indication of pain a patient may be getting from a weight-bearing joint. The period of stance phase of the gait is reduced on the affected side. Look to see if any walking aid is being used correctly. For a right-side d knee or foot problem a stick will be most helpful used in the left hand, for example. Examining the proximal moving part There is a tendency for musculoskeletal lesions around c ertain joints to present with relatively few symptoms at that joint but present with referr ed pain to more distal structures. Examples: \200 Neck lesions causing referred pain into the arm (sepa- rate to radicular distribution senso ry symptoms and pain from any nerve root lesion). Rotator cuff lesions causing referred pai n to the area around the deltoid insertion. Hip lesions causing pain and stiffness in the a nterior thigh and knee. Occasionally, you might come across patients deny having groin or h ip area pain at all. Trendelenberg Leaning over on a painful or weakened hip might indicate a Trendelenberg effe ct. Normally, gluteus medius and mini- mus, which arise from the ileum and insert on the gr eater trochanter, isometrically contract when weight is put on their side to stabilize (abd uct) the femur against the pelvis. This prevents the pelvis sagging on the other side when the leg is lifted on that other side for the swing phase of the gait. If gluteus medius is weak or denervated, or there is reduced lever-arm capacity of abduction (shortened femo- ra l neck, hip instability, pain, etc.) the pelvis can sag on the other side and there is dif \201 culty swinging the leg through on walking. The patient can compensate by leaning over the affected side to reduce the (lever arm effect or ground reaction force) needed to stab ilize the pelvis \200\223 a compen- sated Trendelenberg gait. Passive vs active examination When patients move their own joints (active movement) structu res can move differently compared with when an examiner moves them (passive). This is a key issue appreciated well by physical therapists and musculoskeletal physicians, and develope d initially by Cyriax. \200 Pain elicited by passive examination (which usually is, although may not be, present during active movement of the same structure) suggests an intra-articular lesion. The proviso her e is that your patient \200\231s peri- articular tissues are completely relaxed for your ex amination. Patient-initiated painful movement of the joint (active movement), which lessens or disappears on passive joint examination, suggests involvement of extra-articular tissue s that have a moment of force around that joint (e.g. ligament or tendon). The integrity of systems of joint prime movers and secondary stabilizers can only be examined actively (alt hough isolated speci \201 c lesions can be complex and signs are often not speci \201 c). Physiotherapists refer to weight bearing leg examination as \200\230closed chain \200\231 . Knowledge of the stabilizers (e.g. isometrically operating muscles) around certain joints is essential for Rheumatologists (e.g. the role of short hip abductors in stabilizing the pelvis and avoiding a Trendelenberg gait). Myopathic A myopathic gait is most obvious when there is signi \201 cant quadriceps weakne ss. The dif \201 culty in lifting the legs is compensated for by leaning back slightly and tilting the pelvis forward. Gait can be high stepping if associated with signi \201 cant weakness of tibialis anterior or peroneal muscles, and can be associated with a Trendelenbe rg lurch if associated with hip abductor muscle weakness. High-stepping or foot slap gait The leg is lifted high on swing phase of gait because the a bility to actively dorsi \202 ex and evert the foot to prevent the toe dragging on the gro und is compromised by muscu- lar weakness. Most often due to peroneal nerve damage or compr omise (e.g. L5/S1 radiculopathy). The poor dorsi- \202 exor control can results in the fo ot slapping down. The adult \200\230GALS \200\231 screening examination The locomotor system is complex and dif \201 cult to examine. The gait, arms, leg, and spine (GALS) examination is a selective clinical process to detect important locomotor abnormalities and functional disability. It is based on a tested \200\230minimal \200\231 history and examination system with a simpl e method of recording. The screen is fast and easy to perform, and includes objective obser vation of functional movements relevant to activities of daily living. The GALS screen has been well validated and accepted into the core undergraduate curriculum in UK Medical Schoo ls, and has been taught as a quick and pragmatic screening assessment for use in general pr actice. Functional assessment An assessment of the musculoskeletal (locomotor) system requires an e xamination of moving parts. Functional anat- omy and regional functional assessments are in cluded in Chapter 5. General function is dealed with here. General observation Observing patients even before they enter the consultation room can be helpful in the functional examination. \200 Body habitus/posture. Check for patient walking stooped with kyphosis (intervertebral disc disease or osteoporosis). Does the patient walk bow-legged or with dif \201 culty, what wa lking aids are used, what shoes are being worn, who is accompanying them and what is their role in helping the patient? Is the patient accommodating or protecting painful areas? For example, how does the patient rise from the waiting room chair or do they depend on others to help movement? How is the coat is taken off (?shoulder pain)? Screening history If patients answer \200\230no \200\231 to the following three questions then there is unlikely to be any signi \201 cant musculoskeletal abnormality or disability . \200 Have you any pain or stiffness in your muscles, joints or back? Can you dress yourself comp letely without dif \201 culty? Can you walk up and down stairs without dif \201 culty? \200 RHEUMATOLOGICAL EXAMINATION 10 Examination The patient is examined with him/her wearing only under- wear. The sequence is unimportant. Logically, it is most appropriate to examine gait, spine, arms then legs. Gait : inspect the patient walking, turning, and walking back. Look for: \200 \200 \200 synovitis) and inspect soles of feet for callosities. An abnormal distribution of callositi es can re \202 ect abnormal weight bearing owing to deformities, etc. Rheumatological examination in children The examination of a child with a musculoskeletal p roblem is often opportunistic as they may be in pain. You will gain the best information fr om close observation that starts when the child and family walk in to your consulting room. \200 Symmetry and smoothness of movement. Normal stride length and ability to turn quickly. Norm al heel strike, stance, toe-off, and swing through. Spine: inspect from three views. From t he back inspect for: \200 \200 The child should have their weight and height measured accurately, and plotted onto centile charts. The biological aim of childhood is growth and development, and if either are faili ng, there are major concerns. The essence of the examination is keeping the child engaged a nd not losing their trust by hurting them. Gait (in the mobile child) should be observed wi th the child undressed (but preserving dignity). Pre-school age children are usually happy to walk about in their under- pants; those less con \201 dent need to hold a parent \200 \231s hand. Older children will want more clothes on and it is wise to ask children to brin g shorts to change into. It is normal for toddlers to be \200\230bow legged \200\231 and \200\230 \202 at footed \200\231. In-toeing, out toeing, \200\230curly toes \200\231, and \200\230knock knees \200\231 are all common normal variants. The toddler should, however, be symmetrical and, where there is asymmetry, look carefully for pathology. Intoeing has m any causes, but almost all are simple often age-related biomechanical reasons: \200 \200 \200 \200 \200 A straight spine (no scoliosis). Normal symmetrical para-spinal, shoulder and gluteal muscl es. Level iliac crests. No popliteal swelling and no hind-foot swelling or deformity. \200 From the side ensure there is a normal cervical and lumbar lordosis and very slight thoraci c kyphosis. The patient is then asked to touch his/her toes keeping the knees straight. Lum bar forward \202 exion should be smooth and the lumber spine should adopt a smooth curved shape. Arms: from the front \201 rst ask the patient \200\230 \200 to try to place his /her ear on \201 rst the right then the left shoulder \200 \200\231 This tests for cervi cal \202 exion. From the front ask the patient to complete the following: \200 \200\230Place both hands behind your head, elbows back \200\231. This tests shoulder abduc tion and external rotation. A major glenohumeral or rotator cuff lesion will impair this mo vement. \200\230Place both hands down by your side, elbows straight \200\231. This tests f or full elbow extension. \200\230Place both hands, out in front, palms down, \201 ngers straight, then turn both hands over \200\231. You can identify major wrist or \201 nger s welling, or deformity, palmar muscle wasting or erythema, the ability to supinate the forea rms from the elbow, and fully extend \201 ngers. \200\230Make a tight \201 st with eac h hand then, with both hands, place the tip of each \201 nger in turn onto the tip of you r thumbs \200\231. You can identify any major de \201 cit in the power grip and evaluate t he \201 ne precision pinch movement (thumb opposition). The examiner squeezes across the 2nd to 5th metacarpal. From this tenderness might be elicited, which might sig- nify synovi tis of metacarpophalangeal joints (which might not be detectable by inspection alone). femoral anteversion (age 3 \200\2238 years); internal tibial torsion (up to age 3 \200\2234 years); bow legs \200\223 most resolve by age 3 years; knock knees \200\223 most resolve by age 7 years; \202 at feet \200\223 most resolve by age 6 years and normal arches are seen on standing on tiptoe. Unilateral \200\230out toeing \200\231 can be because of ankle arthritis; severe or asymme trical leg bowing may indicate rickets (more common in the UK in dark skinned children). As ymmetrical skin creases at the groin with leg length discrepancy suggests a late diagnosis of developmental dysplasia of the hip. In juvenile idiopathic arthritis (JIA) an antalgic g ait and asymmetry due to leg length discrepancy are common. Ask the child to sit on the \202 oor then get up unaided. If the child has to turn onto \200\230all fours \200\231 and then \200\230walk up \200\231 their legs using their hands there is proximal muscle weakn ess (Gower \200\231s sign). Perform a general examination, particularly noting any skin ras hes, nail changes, oral ulceration, heart murmurs, lymphadenopathy, and organomegally. Exam ine peripheral neurology, muscle bulk, and strength. An unassisted sit-up or \202 exing t he head against resist- ance are valuable in assessing truncal weakness as found in dermato myositis (DM). In the musculoskeletal examination, check every joint. Because of poor local ization of pain, there may be unex- pected \201 ndings. Check for tenderness over enthese s. Subtle swelling of the ankle joint is best detected from behind the child with the child standing. If a joint looks, feels, and moves normally then it probably is normal! Legs: with the patient standing inspect the legs from the front checking for symmetry, obvi ous knee swelling, knee or hind-foot valgus or varus, and changes to muscle bulk and skin r ashes. Then ask the patient to lie \202 at, supine on the couch. The remainder of the ass essment involves the examiner moving joints (passive joint examination). \200 Flex the hip to 90* with the leg bent holding the knee also at 90*. Repeat for other side. Rotate each hip in \202 exion (swing the foot out). Hips should \202 ex and rotate symm etrically if normal without restriction or pain. During the above maneuver depress the pate lla, feeling for crepitus (often present with knee effusion). Squeeze across metatarsals fo r tenderness at toe bases (typically present if there is metatarsophalangeal joint \200 CHAPTER 1 Clinical assessment of rheumatological disease 11 The pediatric GALS examination The pGALS examination provides an easy screening examination , validated to detect signi \201 cant abnormality with high sensitivity. Following detecti on of an abnormality there may be a detailed focus on it. \200 \200 \200 \200 \200 gait (?lack of arm swinging, shuf \202 ing); limb rigidity; resting tremor (e.g. thumb and fore \201 nger); passive elbow movement for \200\230cogwheeling \200\231. Stiffness is also a feature of slowing evolving myelopathy. Patients with lesions causing m yelopathy present occasion- ally to rheumatologists. Lesions include axial and subaxial cer vical spine stenosis owing to disc and degenerative spine disease or instability in the spi ne associated with rheumatoid arthritis. Key points in the history worth exploring might be : \200 \200 It is best done by getting the child to copy the examiner. It is important to register both non-verbal and verbal indicators of discomfort. A key \201 nding is asymmetry. Neurological examination (adults) A detailed view of neurological examination technique is beyond the scope of this text. However, knowledge of patterns of presentation of neurologic al disease \200\223 particularly spinal cord and peripheral nerve lesions \200\223 is ess ential. Stiffness Stiffness is a common musculoskeletal symptom. It can also be reported in early neurological disease. \200 Any previous spinal trauma. Radicular peripheral limb parasthesias, numbness, or burning pa in. Any long-standing neck or thoracic spine symptoms. Progressive abnormalities in bladder control. \200 The examination of patients with potential myelopathy is necessary detailed. However, often with a slowly evolving lesion, signs can be atypical and in some patients, dif \201 cult to elicit. \200 Back and general, mainly proximal, limb stiffness is a well- recognized features of early P arkinson \200\231s Disease. Think of assessing: \200 Tone and re \202 exes in limbs can be dif \201 cult to assess owing to co-existent joint disease. facial expressivity (?lacking); Table 1.3 The pGALS musculoskeletal screening examination Screening questions Do you (or does your child) have any pain or stiffness in your (their) joints, muscles or b ack? Do you (or does your child) have any dif \201 culty getting yourself (him/herself) dressed without any help? Do you (or does your child) have any problem going up and down stairs? Screening maneuvers Features assessed Examples of abnormalities Observe the child standing (from front, back and sides) Posture Knock knees, bow legs. Habitus Leg length discrepancy, Scoliosis, kyphosis Observe the child walking and \200\230Walk on your tip-toes/walk on your heels \200\231 Feet and ankles Flat feet, antalgic gait, In \202 ammatory arthritis, enthesitis-related arthritis (ERA), sever disease, tarsal coalition \200\230Hold your hands out straight in front of you \200\231 Shoulders, elbows, wrists, hands In \202 ammatory arthritis \200\230Turn your hands over and make a \201 st \200\231 Wrists, elbows, small joints of hands \200\230Pinch your 1st \201 nger and thumb together \200\231 Small joints index \201 nger and thumb \200\230Touch the tips of your \201 ngers \200\231 Small joints of \201 ngers Squeeze the metacarpophalangeal joints (MCP) joints MCP joints \200\230Put your hands together palm to palm and then back to back \200\231 Small joints of \201 ngers, wrists \200\230Reach up, \200\234touch the sky \200\235, and look at the ceiling \200\231 Neck, shoulders, elbows, wrists Hypermobility, in \202 ammatory arthritis \200\230Put your hands behind your neck \200\231 Shoulders, elbows Hypermobility, in \202 ammatory arthritis Feel for effusion at the knee Knee In \202 ammatory arthritis Active movement of knees and feel for crepitus Knee Anterior knee pain Passive movement (full \202 exion and internal rotation of hip) Hip Perthes, slipped femoral epiphysis, hip dysplasia, in \202 ammatory arthritis (ERA) \200\230Open wide and put three (child \200\231s own) \201 ngers in your mouth \200\231 Temporomandibular joints In \202 ammatory arthritis \200\230Try and touch your shoulder with your ear \200\231 Neck In \202 ammatory arthritis, torticollis \200\230Bend forwards and touch your toes \200\231 Thoracolumbar spine Spondylolysis, spondylolisthesis, mechanical back pain, In \202 ammatory arthritis (ERA) Table reproduced, with permission, from: Foster HE, Jandial S. pGALS \200\223 a screening examination of the musculoskeletal system in school-aged children. Reports on the Rheumatic Diseases (Series 5), Hands On 15. Arthritis Research Campaign; 2008 June. RHEUMATOLOGICAL EXAMINATION 12 C2 C3 C2 C3 C4 T4 T2 T4 T7 T2 T2 T7 T10 C5 C5 C5 C5 T12 L1 T1 T1 C6 C6 T10 T1 T1 L3 C6 S5 T12 L2 L2 S4 C6 L1 L1 C8 S3 S3 C8 C8 C8 L2 L2 C7 C7 C7 C7 S2 S2 L3 L3 L3 L3 L5 L5 L5 L5 L4 L4 L4 L4 S1 S1 S1 S1 L5 L5 Figure 1.1 Testing clonus is often inappropriate in patients with joint disease. Plantar responses are not necessarily extensor. Sensory skin testing requires time and a fairly detailed approac h. Patients with RA and other arthritides and AICTDs may have additional (or longstanding) radicular signs or changes in sensory changes from other causes of neuropathy. discriminating the cause of leg pain (joint or muscle pain or lumbar nerve root). \200 Neurogenic pain is often described as \200\230burning \200\231, and is associated with par asthesias ( \200\230tingling \200\231) or \200\230numbness \200\231. A positive Tinnel \200\231s test (parasthesias from percussion over peripheral nerve course at possible sites of entrapment) is an important sign in peripheral nerve entrapment lesions. Knowledge of r adicular and peripheral nerve distribution and function is important (see Appendix). Peripheral limb pain Discriminating pain from musculoskeletal causes, and neurological radi cular or other peripheral nerve lesions can be dif \201 cult. Often multiple lesions exist . \200 Resources ARC pGALS DVD. Available at: www.arc.org.uk/ arthinfo/emedia.asp#pGALS ARC. Avail able at: http://www.arc.org.uk/arthinfo/ medpubs/6535/6535.asp Common scenarios include \200 \200 diagnosing carpal tunnel syndrome; establishing whether neurogenic pains in the hand are fr om median or ulna nerve lesions or nerve root lesions in the neck; CHAPTER 1 Clinical assessment of rheumatological disease 13 Examining the central nervous system. Available at: http://www.scribd.com/doc/19826/Examina tion- of-the-Central-Nervous-System; Further reading Bellamy N. WOMAC Osteoarthritis Index. Available at: www.womac. Foster HE, Kay LJ et al. Musculoskeletal screening examination (pGALS) for school-age child ren based on the adult GALS screen. Arthritis Care Res 2006; 55: 709 \200\22316. Jandial S, Foster H. Examination of the musculoskeletal system in children \200\223 a simp le approach. Paed Child Health 2007; 18(2): 47 \200\22355. org. Observational gait analysis. Available at: http://www.iol.ie/ rcsiorth/ Calin A, Garrett S, Whitelock H, et al. A new approach to de \201 ning functional ability in ankylosing spondylitis: the development of the Bath Ankylosing Spondylitis Functional In dex. J Rheumatol 1994; 21: 2281 \200\2235. journal/volume2/june/gait.htm; Scott DL, Garrood T. Quality of life measures: use and abuse. Baillieres Best Pract Res Clin Rheumatol 2000; 14: 663 \200\22387. Doherty M, Dacre J, Dieppe P, Snaith M. The \200\230GALS \200\231 locomotor screen. Ann Rheum Dis 1992; 51: 1165 \200\2239. PATTERNS OF RHEUMATOLOGICAL DISEASE: OLIGOARTICULAR PAINS IN ADULTS 14 Patterns of rheumatological disease: oligoarticular pains in adults Background In \202 ammation may be a consequence of a range of cellular processes but ther e are no clinical features that are both frequent and speci \201 c enough to allow a diagn osis to be made of its cause in any single joint. \200 Table 1.4 The causes of oligoarticular (including monoarticular) joint pain and typical pat terns of presentation Disease Typical pattern In any given joint synovitis may not be the only in \202 amed tissue. Enthesitis of insert ions of joint capsules, intra-articular and peri-articular ligaments/tendons may be the pri mary site of inflammation in some disorders. The differential diagnosis of synovitis includ es haemar- throsis and other synovial processes, e.g. pigmented villonodular synovitis (PVN S). Gout (p. 383) Age >40 years. Initially acute monoarthritis. Association with hyperuricaemia, renal impairment, diuretics. General symptoms can mimic se psis. Possible family history. High acute phase response. Neutrophilia. Joint \202 uid ur ate crystals seen by polarized light microscopy (PLM). Joint erosions (typical) and tophi o ccur in chronic disease. SpA (p. 209) Age <40 years, men > women. Mostly oligoarticular lower limb joint enthesitis/synovitis. Ma y occur with sacroiliitis, urethritis or cervicitis, uveitis, gut in \202 ammation, psoria sis. Possible family history. ESR/CRP can be normal. More severe in HLAB27 positive people. History: general points \200 Pain and stiffness are typical, although not invariable features of synovitis and enthesiti s. Pain and stiffness are often worse during or after a period of immobility. The presence or absence of stiffness does not discriminate between diagnoses. Pain is often severe in ac ute joint in \202 ammation. There are no descriptors that discriminate pain from synovitis or enthesitis. Swelling, either due to synovial thickening or effusion, often accompanies synovitis. Enthesitis may be associ- ated with peri-articular soft tissue swelling. A patie nt \200\231s report of swelling is not always reliable. CPPDD arthritis (p. 383) Mean age 72 years. Oligoarticular, acute monoarticular (25%) and occasionally polyarticular patterns. Haemarthrosis. Obvious trauma does not always occur. Swelling usually considerab le. Causes include trauma (e.g. cruciate rupture or fracture), PVNS, bleeding diatheses and chondrocalcinosis. Osteoarthritis (p. 371) Soft tissue swelling is usually not as obvious as bony swelling (osteophytes). Typical dist ribution (e.g. \201 rst carpometacarpal and knee joints) Examination: general points \200 Unusual presentation in a single joint. Can present with just a few (usually symmetrical) j oints. Rheumatoid arthritis (p. 197) Skin erythema and heat are common with crystal and septic arthritis. Severely tender swelli ng suggests joint infection, haemarthrosis or an acute in \202 ammatory reaction to crysta ls. In \202 ammation of entheses results in \200\230bony \200\231 ten- derness at joint m argins and sites of tendon or ligament insertion. The degree to which passive and active jo int mobility is reduced depends on a number of interdependent factors (e.g. pain, size of e ffusion, peri-articular muscle weakness or pain). Symptoms elicited by movement of a joint affected by synovitis or enthesitis include pain and stiffness, although neither may be spe ci \201 c. Reaching the end of (reduced) joint range, whether elicited passively or active ly, invariably causes pain (although it should be noted that if any normal joint is forced through the end of range, pain can result). Commonest cause Staphylococcus aureus. Associated with chronic arthritis, joint prostheses and reduced host immunity. Peak incidence in elderly. Systemic symptoms common and sometime s overt, thoughalthough may not occur. Synovial \202 uid is Gram stain positive in 50% of cases and culture positive in 90% of cases. Septic arthritis (excluding N. gonorrhae) Gonococcal arthritis Age 15 \200\22330 years in urban populations and with inherited de \201 ciency of compleme nt C5 to C9. One form presents as an acute septic monoarthritis. Organism detected by Gram stain of joint \202 uid (25%) or culture (50%). Different joints? \200 Shoulder synovitis is typical in hydroxyapatite arthritis and AL amyloidosis. Involvement o f a shoulder or hip is unusual in gout. CPPDD arthritis (as pseudogout) occurs rarely in th e small \201 nger joints. The knee is the commonest site of acute CPPDD arthri- tis, and is the site of about 50% of septic and the majority of gonococcal arthritis cases. Acute ma ssive swelling of the knee is typical in Lyme arthritis and can occur with septic arthritis . Massive swelling of the knee can also occur in psoriatic arthritis but the history is usu ally chronic. There are many theoretical causes of synovitis in a single \201 rst metatar sophalangeal joint (MTPJ), but the majority \200 History Age and gender \200 Oligoar thritis is uncommon in young adults. Spondylarthropathy (SpA), especially reactive arthritis, is likely to be the main cause (e.g. 75% of patients who develop reactive arthri tis are <40 years). Gout typically occurs in those over 40 years and is the commonest cause of in \202 ammatory arthritis in men (self- reported in 1 in 74 men and 1 in 156 women). The mean age of patients with (CPPDD) arthritis is about 70 years (range 63 \200\22393 year s). CHAPTER 1 Clinical assessment of rheumatological disease 15 of cases are due to gout (50 \200\22370% of \201 rst attacks occur in this joint). Both gout and SpA may be familial. About 10% of patients with gout have a family history. G out in young adults suggests an inherited defect (usually increased urate from increased 5- phosphoribosyl- 1-pyrophosphate synthetase, because other de \201 ciencies present in chil dhood). Excessive alcohol consumption is associated with gout. Alcohol can also contribute to lactic acidosis that inhibits urate breakdown. Consider Lyme disease if patients live, w ork or visit endemic areas for infected ticks (within the northeast rural United States, Eu rope, Russia, China, and Japan). Peak incidence of infection is June/July. Brucellar arthri tis is generally monoarticular and occurs in areas where domesticated animals are infected and poor methods of animal husbandry, feeding habits and hygiene standards co-exist. Preceding factors Factors preceding oligoarthritis may be relevant. These include infection and trauma. \200 Acute non-traumatic monoarticular synovitis is most commonly due to crystal-induced synovit is or associ- ated with SpA. A preceding history of trauma might suggest intra-articular fr acture, meniscus tear (knee) or an intra-articular loose body (e.g. osteochondral fragment) . Twinges of joint pain often precede an acute attack of gout. Acute arthritis occurs in 25 % of patients with CPPDD arthritis. An acute monoar thritis with fever in familial Mediterr anean fever (FMF) is a mimic of septic arthritis. Such joint manifestations are a common (7 5% of cases), but not invariable feature. Other associated features Associated features include previous eye, gastrointestinal, cardi ac, and genitourinary symptoms. \200 Crystal arthritis? Crystal arthritis is associated with other conditions. \200 Low-grade fever, malaise, and anorexia occur in septic arthritis and gout. Marked fever occ urs in only about a third of patients with septic arthritis. Marked fever, hypotension, and delirium can occur (rarely) in acute \202 ares of CPPDD arthritis. Try eliciting a histo ry of SpA: \200 \200 \200 \200 \200 Hyperuricaemia, causes of which include obesity, renal insuf \201 ciency, tumor lysis synd rome, myeloproliferative diseases is associated with gout. Hypertension, hypertriglyceridae mia, and a history of urate renal stones are associated with gout. Attacks of gout and CPPD D arthritis can be precipitated by any non-speci \201 c illness, trauma, and surgery. The commonest associated disorder of CPPDD is primary hyperparathyroidism (10% of cases). Thoug h uncommon, hypomagnesaemia, hypophosphata- sia [low alkaline phosphatase (ALP) activity], haemo- chromatosis, Wilson \200\231s disease, and ochronosis are all associated with CPPDD arthritis. back or buttock pain (enthesitis or sacroiliitis); swelling of a digit (dactylitis); planta r heel pain (plantar fasciitis); red eye with irritation (anterior uveitis); urethritis, ba lanitis, cervicitis, or acute diarrhea (reactive arthritis); psoriasis; symptoms of in \202 ammatory bowel disease. \200 Beh et \200\231s disease is a cause of oligoarticular synovitis. Other features inc lude painful oral and genital ulcers, and uveitis. The involvement of more than one joint d oes not rule out septic arthritis. In up to 20% of cases, multiple joints can become infect ed. Link with infection Many types of infection are linked to oligoarticular arthritis. \200 Viruses, bacteria, protozoa, helminthes, and fungi can all directly invade joints. The rang e of systemic features is wide and pathogens can cause both polyarticular and oligoarticula r joint conditions. The infections recognized to trigger reactive arthritis are Salmonella, Yersinia, Shigella, Campylobacter, and Chlamydia. Reactive arthritis in those who acquire chlamydial (non-gonococcal) urethritis is relatively uncommon (about 1 in 30). Acute HIV in fection is associated with a subacute oligoarticular arthritis (usually knees and ankles). Chronic arthritis of any type, diabetes, immunode \201 - ciency, regular dialysis, chronic renal failure, and joint prostheses are risks for septic arthritis. Lyme disease should be considered a cause of oligoarthritis in patients with a history (weeks to years ago) of er ythema chronicum migrans [macule/papule initially, expanding 0.5 \200\2231 cm/day to a mean diameter of 15 cm (range 3 \200\22368 cm) fading often without treatment in 3 \200\2234 we eks]. A history of circumcorneal eye redness with pain, pho- tophobia, and blurred vision m ay be due to anterior uveitis \200\223 associated with SpA, but also sarcoid, Beh et \200 \231s, and Whipple \200\231s disease. Examination General Always compare sides. Establish whether there is true synovial swelling . A history of swelling is not always reliable. Enthesial in \202 ammation in SpA does not usually cause swelling. Affected joints Examine for tenderness. Check the range of (passive) movement, for locking and instability. \200 Acute processes, such as crystal arthritis and infection often lead to a painful swelling, marked tenderness of swollen soft-tissues, and painfully restricted active and passive move ment of the joint. Features are usually less overt with chronic arthritis. Instability of a n acutely in \202 amed joint or tests for carti- lage damage in the knee may be dif \201 cult to demonstrate. Further examination will be necessary after drainage of joint \202 u id/haemarthrosis. Detection of enthesis tenderness around the affected joints or at other s ites is a useful clue to the underlying diagnosis of SpA. Family and social history There may be important clues from the family and social history. PATTERNS OF RHEUMATOLOGICAL DISEASE: OLIGOARTICULAR PAINS IN ADULTS 16 Lipid and cholesterol crystals are not uncommon in joint \202 uid samples, but their sign i \201 cance is unknown. Crystals seen less commonly, but in typical settings include hydr oxyapatite associated with Milwaukee shoul- der (or knee) syndrome (alizarin red-S stain po sitive), calcium oxalate in dialysis patients (may need scanning electron microscopy), cyst ine in cystinosis, and xanthine in xanthinosis. The presence of crystals in joint \202 ui d does not exclude infection. The commonest causes of non-gonococcal septic arthritis in Eu rope and North America are Staph aureus (40 \200\22350%), Staph epidermidis (10 \200\22315% ), Strep species (20%), and Gram-negative bacteria (15%). Examination of other musculoskeletal structures \200 Examine the back and for sites of bony tenderness. Sacroiliitis and enthesitis are common i n SpA. Tendonitis is not speci \201 c and can often occur in gout, CPPDD arthritis, SpA, a nd gonococcal infection. Skin rashes and other features of in \202 ammation Oligoarthritis may be part of a systemi c in \202 ammatory/ infective condition. \200 Temperature and tachycardia can occur with non-infective causes of acute arthritis (e.g. cr ystal arthritis), although their presence with oligoarticular joint swelling requires exclu sion of joint infection. Gouty tophi may be seen in the pinnae, but also any- where periphe rally. They can be dif \201 cult to discriminate clinically from rheumatoid nodules. Polar ized light micro- scopy (PLM) of material obtained by needle aspiration will be diagnostic for tophi. The hallmark of relapsing polychondritis is lobe-sparing, full thickness in \202 ammation of the pinna. Mouth ulcers can occur with any illness; however, crops of larg e painful lesions associated with oligo-articular arthritis suggests Beh et \200\231s dise ase. A typical site for osteitis associated with axial sarcoid or SAPHO (Le Syndrome, Acn , Pustulose, Hyperostose et Osteit ) is manubriosternal. Erythema over a joint suggests cr ystal or infection. Associated skin rashes may include erythema nodosum (associated with an kle pains in sarcoid), the purpuric pustular rashes of Beh et \200\231s, gonococcal infect ion (single pustules) and Le SAPHO, erythema marginatum (rheu- matic fever), or keratoderma blenhorragica (aggressive- looking psoriasis-like rash of the sole of the foot in reactive arthritis disease). Psoriasis may be associated with synovitis, enthesitis or periostitis. Table 1.5 Features of joint \202 uid Feature Normal Non- In \202 ammatory Septic in \202 ammatory Viscosity V high High Low Varies Color None Straw Straw Varies + orgs Clarity Clear Clear Opaque Opaque 200 200 \200\2232000 2000 \200\22350 000 >50 000 Leucocytes (cells/mm3) \200 PMNs (%) <25 25 Often >50 >75 Radiographs Radiographs can con \201 rm an effusion, show characteristic patterns of chond ral and bone destruction (e.g. in infection or erosive gout), and show intra-articular calc i \201 cation from CPPDD or hydroxyapatite. \200 If septic arthritis is suspected radiographs are essential. Patchy osteopaenia and loss of bone cortex are cardinal signs. Punched-out (Lulworth Cove) erosions, soft tissue swellings (tophi) and patchy calci \201 cation are hallmarks of chronic gout. Intra-articular calci \201 cation may be either chondrocalci- nosis ( \201 ne linear or punctate \201 brocar tilage calci \201 cation) or larger loose bodies (often with osteophytes). Both associate with CPPDD arthritis. Numerous round-shaped calci \201 c masses in a joint can be due to s ynovial chondromatosis (commonest in middle- aged men, 50% of cases \200\223 knee). The pr esence of erosions per se does not imply RA. Erosions can be due to erosive enthesitis asso ciated with SpA, CPPDD arthritis, and gout. Investigations Doubt about the presence of synovitis can be addressed by obtaining US or ma gnetic resonance (MR) imaging of the joint(s) in question. Joint aspiration (see Table 1.5) Fluid should be sent in sterile bottles for microscopy and culture. \200 Synovial \202 uid appearances are not speci \201 c. Blood or blood-staining suggests hae marthrosis from trauma (including the aspiration attempt), haemangioma, PVNS, synovioma, or occasionally CPPDD arthritis. Turbidity of \202 uid relates to cellular, crystal, lipid, and \201 brinous content, and is typical in septic arthritis and acute crystal arthritis owing to the number of polymor- phonuclear (PMN) leucocytes. Cell counts give some diagnos tic guidance, but are non-speci \201 c. There is a high probability of infection or gout i f the PMN differential is >90%. Joint \202 uid eosinophilia is not speci \201 c. Compens ated PLM of fluid can discriminate urate (3 \200\22320 m, needle-shaped, negatively biref ringent \200\223 blue and then yellow as the red plate compensator is rotated 90 ) and ca lcium-containing crystals, e.g. CPPDD (posi- tively birefringent, typically small, and rect angular or rhomboid in shape). MR Further MR imaging should be discussed with your radiologists. \200 Confirmation of traumatized structures, such as meniscus damage in the knee and labral dama ge in the shoulder should be sought if suspected. MR can con \201 rm synovitis, although a ppearances are usually non-speci \201 c. Focal high signal in bone on T2 and fat suppresse d images ( \200\230bone bruising \200\231) if in sub-enthesial sites can indicate osteitis in SpA. \200 CHAPTER 1 Clinical assessment of rheumatological disease 17 Serum angiotensin converting enzyme (sACE) (occurs in, although is not speci \201 c for, s arcoid), IgM Borellia burg- dorferi serology (acute arthritis or history of migratory arthr itis in Lyme disease). Antibodies to the streptococcal antigens streptolysin O (ASOT) DNAas e B, hyaluronidase, and streptozyme in patients who have had sore throat, migratory arthrit is or features of rheumatic fever. Ultrasound Many rheumatologists use US to aid diagnosis and characterize in \202 ammatory arthritis in the clinic. \200 Joint and tendon thickening, and changes in appearance of soft-tissues are all identi \201