{"id":36950,"date":"2026-06-06T09:03:11","date_gmt":"2026-06-06T03:33:11","guid":{"rendered":"https:\/\/atsixty.com\/?p=36950"},"modified":"2026-06-06T09:03:45","modified_gmt":"2026-06-06T03:33:45","slug":"seronegative-spondyloarthropathies","status":"publish","type":"post","link":"https:\/\/atsixty.com\/index.php\/neet-pg\/seronegative-spondyloarthropathies\/","title":{"rendered":"Seronegative Spondyloarthropathies"},"content":{"rendered":"\n\n\n<meta charset=\"UTF-8\">\n<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n<title>Morning Rounds \u00b7 Seronegative Spondyloarthropathies<\/title>\n<link href=\"https:\/\/fonts.googleapis.com\/css2?family=Playfair+Display:ital,wght@0,400;0,600;0,700;1,400;1,600&#038;family=Source+Serif+4:ital,wght@0,300;0,400;0,600;1,400&#038;display=swap\" rel=\"stylesheet\">\n<style>\n#rhmq03 *,#rhmq03 *::before,#rhmq03 *::after{box-sizing:border-box;margin:0;padding:0}\n#rhmq03{\n  --ter:#8B3D20;\n  --ter-light:#B85A38;\n  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.mr-retry:hover{background:var(--ter);color:#FFFDF9}\n@media(max-width:480px){#rhmq03 .mr-title{font-size:1.4rem}#rhmq03 .mr-num{font-size:1.7rem}#rhmq03 .mr-stem{font-size:0.9rem}#rhmq03 .mr-opt-text{font-size:0.86rem}}\n<\/style>\n\n<!-- HLA-B27 disease associations diagram for Q1 debrief -->\n<div id=\"rhmq03-img1\" style=\"display:none\">\n  <figure class=\"mr-img-wrap\">\n    <svg viewBox=\"0 0 540 210\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:100%;max-width:540px;display:block;margin:0 auto\">\n      <!-- Background -->\n      <rect x=\"0\" y=\"0\" width=\"540\" height=\"210\" rx=\"10\" fill=\"#F4F8F6\"\/>\n      <!-- Centre label -->\n      <ellipse cx=\"270\" cy=\"105\" rx=\"52\" ry=\"28\" fill=\"#8B3D20\" opacity=\"0.9\"\/>\n      <text x=\"270\" y=\"100\" text-anchor=\"middle\" fill=\"#fff\" font-size=\"11\" font-family=\"Georgia,serif\" font-weight=\"bold\">HLA-B27<\/text>\n      <text x=\"270\" y=\"115\" text-anchor=\"middle\" fill=\"rgba(255,255,255,0.8)\" font-size=\"9\" font-family=\"Georgia,serif\">MHC Class I<\/text>\n      <!-- AS node -->\n      <ellipse cx=\"270\" cy=\"28\" rx=\"62\" ry=\"18\" fill=\"#3D5A80\" opacity=\"0.85\"\/>\n      <text x=\"270\" y=\"24\" text-anchor=\"middle\" fill=\"#fff\" font-size=\"9.5\" font-family=\"Georgia,serif\" font-weight=\"bold\">Ankylosing Spondylitis<\/text>\n      <text x=\"270\" y=\"37\" text-anchor=\"middle\" fill=\"rgba(255,255,255,0.8)\" font-size=\"8.5\" font-family=\"Georgia,serif\">90% positive<\/text>\n      <line x1=\"270\" y1=\"46\" x2=\"270\" y2=\"77\" stroke=\"#3D5A80\" stroke-width=\"1.5\" stroke-dasharray=\"4,2\"\/>\n      <!-- ReA node -->\n      <ellipse cx=\"90\" cy=\"68\" rx=\"62\" ry=\"18\" fill=\"#2D6B47\" opacity=\"0.85\"\/>\n      <text x=\"90\" y=\"64\" text-anchor=\"middle\" fill=\"#fff\" font-size=\"9.5\" font-family=\"Georgia,serif\" font-weight=\"bold\">Reactive Arthritis<\/text>\n      <text x=\"90\" y=\"77\" text-anchor=\"middle\" fill=\"rgba(255,255,255,0.8)\" font-size=\"8.5\" font-family=\"Georgia,serif\">60&#8211;80% positive<\/text>\n      <line x1=\"146\" y1=\"78\" x2=\"220\" y2=\"97\" stroke=\"#2D6B47\" stroke-width=\"1.5\" stroke-dasharray=\"4,2\"\/>\n      <!-- PsA node -->\n      <ellipse cx=\"450\" cy=\"68\" rx=\"62\" ry=\"18\" fill=\"#7B5EA7\" opacity=\"0.85\"\/>\n      <text x=\"450\" y=\"64\" text-anchor=\"middle\" fill=\"#fff\" font-size=\"9.5\" font-family=\"Georgia,serif\" font-weight=\"bold\">Psoriatic Arthritis<\/text>\n      <text x=\"450\" y=\"77\" text-anchor=\"middle\" fill=\"rgba(255,255,255,0.8)\" font-size=\"8.5\" font-family=\"Georgia,serif\">axial: 50&#8211;70%<\/text>\n      <line x1=\"394\" y1=\"78\" x2=\"320\" y2=\"97\" stroke=\"#7B5EA7\" stroke-width=\"1.5\" stroke-dasharray=\"4,2\"\/>\n      <!-- IBD-SpA node -->\n      <ellipse cx=\"90\" cy=\"148\" rx=\"62\" ry=\"18\" fill=\"#C07828\" opacity=\"0.85\"\/>\n      <text x=\"90\" y=\"144\" text-anchor=\"middle\" fill=\"#fff\" font-size=\"9.5\" font-family=\"Georgia,serif\" font-weight=\"bold\">IBD-SpA<\/text>\n      <text x=\"90\" y=\"157\" text-anchor=\"middle\" fill=\"rgba(255,255,255,0.8)\" font-size=\"8.5\" font-family=\"Georgia,serif\">25&#8211;75% (axial)<\/text>\n      <line x1=\"146\" y1=\"138\" x2=\"220\" y2=\"113\" stroke=\"#C07828\" stroke-width=\"1.5\" stroke-dasharray=\"4,2\"\/>\n      <!-- Uveitis node -->\n      <ellipse cx=\"450\" cy=\"148\" rx=\"62\" ry=\"18\" fill=\"#B83232\" opacity=\"0.85\"\/>\n      <text x=\"450\" y=\"144\" text-anchor=\"middle\" fill=\"#fff\" font-size=\"9.5\" font-family=\"Georgia,serif\" font-weight=\"bold\">Acute Ant. Uveitis<\/text>\n      <text x=\"450\" y=\"157\" text-anchor=\"middle\" fill=\"rgba(255,255,255,0.8)\" font-size=\"8.5\" font-family=\"Georgia,serif\">50% of cases B27+<\/text>\n      <line x1=\"394\" y1=\"138\" x2=\"320\" y2=\"113\" stroke=\"#B83232\" stroke-width=\"1.5\" stroke-dasharray=\"4,2\"\/>\n      <!-- nr-axSpA node -->\n      <ellipse cx=\"270\" cy=\"192\" rx=\"72\" ry=\"16\" fill=\"#1A6B5A\" opacity=\"0.85\"\/>\n      <text x=\"270\" y=\"188\" text-anchor=\"middle\" fill=\"#fff\" font-size=\"9.5\" font-family=\"Georgia,serif\" font-weight=\"bold\">nr-axSpA (no X-ray sacroiliitis)<\/text>\n      <text x=\"270\" y=\"199\" text-anchor=\"middle\" fill=\"rgba(255,255,255,0.8)\" font-size=\"8\" font-family=\"Georgia,serif\">MRI active sacroiliitis; B27 supports diagnosis<\/text>\n      <line x1=\"270\" y1=\"176\" x2=\"270\" y2=\"133\" stroke=\"#1A6B5A\" stroke-width=\"1.5\" stroke-dasharray=\"4,2\"\/>\n    <\/svg>\n    <figcaption>\n      HLA-B27 and the seronegative spondyloarthropathies. Prevalence of B27 positivity varies by disease and subtype. <strong>Ankylosing spondylitis carries the highest association (90%)<\/strong>. In Reactive Arthritis, B27 predicts a more severe and prolonged course. Peripheral PsA is often B27-negative; axial involvement is B27-associated. Acute anterior uveitis \u2014 the most common extra-articular feature across all SpA \u2014 is B27-positive in ~50% of cases.\n    <\/figcaption>\n  <\/figure>\n<\/div>\n\n<div id=\"rhmq03\">\n\n  <div class=\"mr-header\">\n    <div class=\"mr-eyebrow\">Morning Rounds &middot; Rheumatology Series &middot; Round 03<\/div>\n    <div class=\"mr-title\">\n      Seronegative Spondyloarthropathies<br><em>Clinical Reasoning<\/em>\n    <\/div>\n    <div class=\"mr-subtitle\">Five high-yield clinical cases &middot; +4 \/ &minus;1 scoring &middot; NEET-PG and UPSC CMS<\/div>\n    <div class=\"mr-chips\">\n      <span class=\"mr-chip\">5 Cases<\/span>\n      <span class=\"mr-chip\">+4 \/ &minus;1 scoring<\/span>\n      <span class=\"mr-chip\">Options reshuffled<\/span>\n    <\/div>\n  <\/div>\n\n  <div class=\"mr-sentinel\" id=\"rhmq03-sentinel\"><\/div>\n\n  <div class=\"mr-progress\" id=\"rhmq03-progress\">\n    <div class=\"mr-prog-inner\">\n      <div class=\"mr-pips\" id=\"rhmq03-pips\"><\/div>\n    <\/div>\n  <\/div>\n\n  <div class=\"mr-body\">\n    <div id=\"rhmq03-cases\"><\/div>\n    <div class=\"mr-submit-wrap\">\n      <button class=\"mr-btn\" id=\"rhmq03-submit\">Submit for Debrief<\/button>\n    <\/div>\n    <div class=\"mr-score\" id=\"rhmq03-score\">\n      <div class=\"mr-score-in\">\n        <div class=\"mr-score-ey\">Round Complete<\/div>\n        <div class=\"mr-ring\" id=\"rhmq03-ring\">\n          <div class=\"mr-ring-in\">\n            <span class=\"mr-ring-pct\" id=\"rhmq03-pct\">0%<\/span>\n            <span class=\"mr-ring-sub\">net<\/span>\n          <\/div>\n        <\/div>\n        <div class=\"mr-score-title\">Your Debrief<\/div>\n        <div class=\"mr-score-net\" id=\"rhmq03-net\"><\/div>\n        <div class=\"mr-verdict\" id=\"rhmq03-verdict\"><\/div>\n        <div class=\"mr-bands\">\n          <span class=\"mr-band mr-band-c\" id=\"rhmq03-ct-c\"><\/span>\n          <span class=\"mr-band mr-band-w\" id=\"rhmq03-ct-w\"><\/span>\n          <span class=\"mr-band mr-band-s\" id=\"rhmq03-ct-s\"><\/span>\n        <\/div>\n        <button class=\"mr-retry\" id=\"rhmq03-retry\">&#8635; New Round<\/button>\n      <\/div>\n    <\/div>\n  <\/div>\n\n<\/div><!-- end #rhmq03 -->\n\n<script>\n(function () {\n  'use strict';\n\n  var NS    = 'rhmq03';\n  var TOTAL = 5;\n  var MAX   = 20;\n  var LTRS  = ['A','B','C','D'];\n\n  var QS = [\n\n    \/* ---- Q1 : Ankylosing Spondylitis \u2014 Imaging & HLA-B27 ---- *\/\n    {\n      id:    1,\n      diff:  'Easy',\n      tag:   'Ankylosing Spondylitis &mdash; Imaging',\n      stem:  'A <strong>26-year-old HLA-B27 positive man<\/strong> presents with a 3-year history of insidious low back pain with prominent morning stiffness lasting over one hour, improving with exercise and worsening with rest. Plain X-ray of the pelvis shows <strong>bilateral grade III sacroiliitis<\/strong> with blurring and erosion of the sacroiliac joint margins. Lumbar spine X-ray shows early <strong>syndesmophyte formation<\/strong> at multiple levels. Which statement regarding the radiological progression of his disease is <em>most accurate<\/em>?',\n      correct: 'Syndesmophytes in AS are thin, vertical, and marginal, arising from the outer fibres of the annulus fibrosus; they bridge adjacent vertebral bodies to produce the bamboo spine appearance',\n      opts: [\n        'Syndesmophytes in AS are thin, vertical, and marginal, arising from the outer fibres of the annulus fibrosus; they bridge adjacent vertebral bodies to produce the bamboo spine appearance',\n        'Syndesmophytes in AS are chunky, horizontal, and paravertebral, identical in appearance to the osteophytes of DISH (diffuse idiopathic skeletal hyperostosis)',\n        'The earliest X-ray finding in AS sacroiliitis is subchondral sclerosis on the iliac side only, because the cartilage is thicker on the sacral side and erodes later',\n        'MRI of the sacroiliac joints is only indicated after plain X-ray shows definite grade III sacroiliitis, as MRI findings in early disease are non-specific and unreliable'\n      ],\n      exp:   '<strong>Syndesmophytes<\/strong> are bony bridges arising from ossification of the outer fibres of the <em>annulus fibrosus<\/em>. They are characteristically <strong>thin, vertical, and marginal<\/strong> \u2014 running along the outer edge of the disc from one vertebral body to the next. Progressive ossification produces the classical <strong>bamboo spine<\/strong> (continuous bony bridging of the entire lumbar and thoracic spine). This contrasts sharply with <strong>DISH osteophytes<\/strong>, which are flowing, irregular, and arise from the anterior longitudinal ligament \u2014 never marginal. In sacroiliitis, <strong>both iliac and sacral sides<\/strong> are affected, though the iliac side (with thinner cartilage) erodes first. <strong>MRI<\/strong> detects active sacroiliitis (bone marrow oedema \u2014 the STIR sequence) years before plain X-ray changes, and is the investigation of choice for <strong>non-radiographic axial SpA (nr-axSpA)<\/strong>.',\n      extra: '<strong>Modified New York Criteria for AS<\/strong> (the exam-standard diagnostic criteria): at least one clinical criterion (inflammatory back pain &ge;3 months; limitation of lumbar spine motion in both sagittal and frontal planes; limitation of chest expansion) PLUS a radiological criterion (bilateral sacroiliitis grade &ge;2, or unilateral sacroiliitis grade &ge;3). Radiological criterion alone without any clinical criterion is <em>insufficient<\/em>. <strong>Grade of sacroiliitis<\/strong>: 0 = normal; I = suspicious; II = minimal (small erosions, sclerosis); III = moderate (erosions, widening\/narrowing, partial ankylosis); IV = complete ankylosis. <strong>Schober\\'s test<\/strong>: marks 10 cm above and 5 cm below the lumbosacral junction; on maximal forward flexion, the distance should increase by &ge;5 cm. In AS, this increase is reduced \u2014 a direct measure of lumbar mobility loss.',\n      imgId: 'rhmq03-img1'\n    },\n\n    \/* ---- Q2 : Reactive Arthritis (ReA) ---- *\/\n    {\n      id:    2,\n      diff:  'Medium',\n      tag:   'Reactive Arthritis',\n      stem:  'A <strong>28-year-old man<\/strong> presents with a <strong>2-week history of painful swelling of the right knee and left ankle<\/strong>, conjunctivitis, and dysuria. He recalls an episode of <strong>watery diarrhoea three weeks ago<\/strong> that resolved without treatment. He is HLA-B27 positive. Examination reveals circinate balanitis and keratoderma blennorrhagica on his palms and soles. Synovial fluid from the right knee shows 18,000 WBC\/mm&sup3; with 80% neutrophils; no organisms on Gram stain; no crystals. Urethral swab is negative for <em>Chlamydia trachomatis<\/em>. Which statement most accurately characterises this presentation?',\n      correct: 'This is post-enteric reactive arthritis triggered by a preceding gastrointestinal infection; the negative Chlamydia swab does not exclude the diagnosis, and keratoderma blennorrhagica is pathognomonic of reactive arthritis',\n      opts: [\n        'This is post-enteric reactive arthritis triggered by a preceding gastrointestinal infection; the negative Chlamydia swab does not exclude the diagnosis, and keratoderma blennorrhagica is pathognomonic of reactive arthritis',\n        'The negative urethral swab for Chlamydia excludes sexually acquired reactive arthritis, and in the absence of a confirmed triggering organism the diagnosis cannot be made; septic arthritis from a gram-negative organism must be excluded first by synovial fluid culture',\n        'Circinate balanitis and keratoderma blennorrhagica indicate concurrent psoriatic arthritis, not reactive arthritis; the diarrhoeal illness was incidental and the oligoarthritis should be evaluated for psoriatic disease',\n        'The synovial WBC of 18,000\/mm&sup3; with 80% neutrophils confirms septic arthritis regardless of the negative Gram stain; empirical IV antibiotics must be started immediately before synovial fluid culture results return'\n      ],\n      exp:   '<strong>Reactive Arthritis (ReA)<\/strong> is a sterile, immune-mediated arthritis triggered by a remote infection (typically 1&ndash;4 weeks prior), most commonly <em>Chlamydia trachomatis<\/em> (urogenital) or enteric pathogens (<em>Salmonella, Shigella, Yersinia, Campylobacter<\/em>). The classic triad \u2014 <strong>arthritis + urethritis + conjunctivitis<\/strong> (&ldquo;can&rsquo;t see, can&rsquo;t pee, can&rsquo;t climb a tree&rdquo;) \u2014 is present in only ~30% of cases. <strong>Keratoderma blennorrhagica<\/strong> (hyperkeratotic plaques on palms\/soles, histologically identical to pustular psoriasis) is <em>pathognomonic<\/em> of ReA. <strong>Circinate balanitis<\/strong> (shallow painless penile ulcers) is also characteristic. A negative Chlamydia swab does not exclude ReA \u2014 the triggering infection has often cleared by the time arthritis presents. Synovial fluid in ReA is inflammatory (5,000&ndash;50,000 WBC, neutrophil-predominant) but sterile.',\n      extra: '<strong>Distinguishing ReA from septic arthritis<\/strong>: both give neutrophil-predominant synovial fluid. Key points: WBC &gt;50,000\/mm&sup3; strongly suggests septic arthritis; &lt;50,000 does not exclude it. Gram stain is only ~60% sensitive for septic arthritis. Always send synovial fluid for culture. In ReA, multiple joints are often involved (oligoarthritis); septic arthritis is typically monoarticular. <strong>HLA-B27 in ReA<\/strong>: B27-positive patients are more likely to develop a severe, prolonged course with sacroiliitis and axial involvement. B27 does NOT cause ReA \u2014 it modifies severity. <strong>Treatment<\/strong>: NSAIDs are first-line. If Chlamydia is confirmed (or strongly suspected), a 3-month course of doxycycline reduces the risk of chronicity. DMARDs (sulfasalazine) are used for persistent disease &gt;6 months. Antibiotics do not modify post-enteric ReA.',\n      imgId: null\n    },\n\n    \/* ---- Q3 : Psoriatic Arthritis \u2014 Patterns ---- *\/\n    {\n      id:    3,\n      diff:  'Medium',\n      tag:   'Psoriatic Arthritis &mdash; Patterns &amp; Diagnosis',\n      stem:  'A <strong>42-year-old woman<\/strong> with a <strong>15-year history of plaque psoriasis<\/strong> presents with swelling of the <strong>entire right index finger<\/strong> (sausage finger), asymmetric oligoarthritis of the right knee and left ankle, and nail pitting with onycholysis. X-ray of the hands shows <strong>pencil-in-cup deformity<\/strong> at the right index DIP joint and periosteal new bone formation. Rheumatoid factor is negative. Which of the following statements regarding her arthritis is <em>most accurate<\/em>?',\n      correct: 'Dactylitis (sausage digit) results from combined tenosynovitis and arthritis of the flexor tendon sheath; pencil-in-cup deformity at the DIP joint is characteristic of the mutilans (destructive) subtype of psoriatic arthritis and indicates severe erosive disease',\n      opts: [\n        'Dactylitis (sausage digit) results from combined tenosynovitis and arthritis of the flexor tendon sheath; pencil-in-cup deformity at the DIP joint is characteristic of the mutilans (destructive) subtype of psoriatic arthritis and indicates severe erosive disease',\n        'Isolated DIP joint involvement with nail changes is a pattern unique to osteoarthritis; the psoriatic skin disease is coincidental and her joint disease should be evaluated as seronegative RA until proven otherwise',\n        'Pencil-in-cup deformity is the earliest radiological finding in psoriatic arthritis, preceding clinical joint swelling by several years, and identifies patients who should receive immediate biologic therapy regardless of disease activity score',\n        'Dactylitis in psoriatic arthritis is caused exclusively by synovitis of the MCP and PIP joints simultaneously and is pathophysiologically identical to the symmetric small joint swelling of rheumatoid arthritis'\n      ],\n      exp:   'Psoriatic arthritis (PsA) has <strong>five recognised clinical patterns<\/strong>: (1) Asymmetric oligoarthritis (most common, 40%); (2) Symmetric polyarthritis (RA-like but RF-negative, 25%); (3) <strong>DIP-predominant<\/strong> disease with nail changes; (4) <strong>Arthritis mutilans<\/strong> (destructive, &lt;5%) \u2014 the most severe form, characterised by <strong>pencil-in-cup deformity<\/strong> (resorption of the phalangeal head leaving a pointed &ldquo;pencil&rdquo; sitting in the eroded &ldquo;cup&rdquo; of the adjacent bone) and telescoping of the digits (opera-glass hand); (5) Axial SpA pattern (sacroiliitis, often asymmetric). <strong>Dactylitis<\/strong> (sausage digit) is characteristic of PsA and results from inflammation of the entire digital ray \u2014 synovitis of the joints plus tenosynovitis of the flexor tendon sheath. It can involve toes as well as fingers.',\n      extra: '<strong>CASPAR Criteria for PsA<\/strong> (Classification Criteria for Psoriatic Arthritis, 2006): inflammatory articular disease PLUS a score of &ge;3 from: current psoriasis (2 points), personal history of psoriasis (1 point), family history of psoriasis (1 point), nail dystrophy\/pitting\/onycholysis (1 point), negative RF (1 point), current or history of dactylitis (1 point), juxta-articular new bone formation on X-ray (1 point). Sensitivity 91.4%, specificity 98.7%. <strong>Nail disease in PsA<\/strong>: occurs in 80&ndash;90% of PsA patients vs ~30% of uncomplicated psoriasis \u2014 nail disease is a strong predictor of PsA development. <strong>Enthesitis<\/strong> (inflammation at tendon\/ligament insertion points \u2014 Achilles tendon, plantar fascia) is another hallmark of SpA seen commonly in PsA and AS. MRI or USS detects enthesitis before clinical signs develop.',\n      imgId: null\n    },\n\n    \/* ---- Q4 : AS Treatment \u2014 NSAIDs to Biologics ---- *\/\n    {\n      id:    4,\n      diff:  'Hard',\n      tag:   'Ankylosing Spondylitis &mdash; Treatment Escalation',\n      stem:  'A <strong>34-year-old man<\/strong> with confirmed radiographic axial SpA (bilateral grade III sacroiliitis, bamboo spine at L1&ndash;L4) has been on two consecutive NSAIDs at maximum tolerated doses for <strong>four weeks each<\/strong> without adequate symptom control. His BASDAI score is <strong>6.8<\/strong>. CRP is markedly elevated. He has no history of recurrent infections or tuberculosis exposure. A Mantoux test is negative and CXR is normal. His physician is considering a biologic agent. Which of the following statements regarding his management is <em>most accurate<\/em>?',\n      correct: 'He fulfils ASAS criteria for biologic therapy (BASDAI &ge;4 after two NSAID trials); a TNF inhibitor is first-line biologic; unlike RA, cDMARDs such as methotrexate have no efficacy for axial disease and should not be used as a step between NSAIDs and biologics',\n      opts: [\n        'He fulfils ASAS criteria for biologic therapy (BASDAI &ge;4 after two NSAID trials); a TNF inhibitor is first-line biologic; unlike RA, cDMARDs such as methotrexate have no efficacy for axial disease and should not be used as a step between NSAIDs and biologics',\n        'He should be trialled on sulfasalazine and methotrexate in combination for at least three months before biologic therapy is considered, as cDMARD combination therapy is the required bridge between NSAIDs and biologics in axial SpA',\n        'A BASDAI of 6.8 is insufficient to justify biologic therapy in the absence of an elevated CRP; objective inflammation must be confirmed on MRI sacroiliac joints showing active bone marrow oedema before ASAS criteria are considered met',\n        'IL-17 inhibitors (secukinumab) are preferred over TNF inhibitors as first-line biologics in axial SpA due to superior efficacy in all subgroups, including those with concurrent inflammatory bowel disease'\n      ],\n      exp:   '<strong>ASAS\/EULAR recommendations for biologic therapy in axial SpA<\/strong>: indicated when BASDAI &ge;4 (on a 0&ndash;10 scale) AND the assessor agrees the disease is active, AND two NSAIDs at maximum tolerated doses for at least 4 weeks each have failed. <strong>CRP elevation or MRI sacroiliitis supports the decision but is not mandatorily required<\/strong> in the current ASAS criteria. Critically, <strong>cDMARDs (methotrexate, sulfasalazine, leflunomide) have no proven efficacy for axial disease<\/strong> \u2014 this is a fundamental distinction from RA. Sulfasalazine may help peripheral arthritis in SpA but not axial symptoms. <strong>TNF inhibitors<\/strong> (adalimumab, etanercept, infliximab, golimumab, certolizumab) are established first-line biologics with comparable efficacy.',\n      extra: '<strong>TNF inhibitors vs IL-17 inhibitors in axial SpA<\/strong>: IL-17A inhibitors (secukinumab, ixekizumab) are <em>equally effective<\/em> to TNF inhibitors for axial SpA and are an alternative first-line biologic. However, there is one critical exception: <strong>IL-17 inhibitors are contraindicated in inflammatory bowel disease (IBD)<\/strong> \u2014 they can worsen Crohn\\'s disease and are not recommended in UC. TNF inhibitors (especially monoclonal antibodies: adalimumab, infliximab) are <em>preferred<\/em> in SpA patients with concurrent IBD. <strong>Pre-biologic screening (mandatory before any biologic)<\/strong>: TB screening (Mantoux + CXR &plusmn; IGRA); hepatitis B serology (HBsAg, anti-HBc); HIV; varicella immunity. Active TB, untreated hepatitis B, and serious active infections are absolute contraindications. Latent TB requires prophylactic isoniazid for at least 4 weeks before starting anti-TNF therapy.',\n      imgId: null\n    },\n\n    \/* ---- Q5 : IBD-Associated SpA vs AS \u2014 Distinguishing Features ---- *\/\n    {\n      id:    5,\n      diff:  'Hard',\n      tag:   'IBD-Associated SpA &mdash; vs AS',\n      stem:  'A <strong>31-year-old woman<\/strong> with a <strong>6-year history of Crohn\\'s disease<\/strong> (terminal ileum involvement, currently in remission on azathioprine) presents with <strong>two episodes of acute painful swelling of her right knee and left ankle<\/strong> over the past eight months, each lasting 4&ndash;8 weeks and resolving spontaneously. She also has a <strong>3-month history of inflammatory low back pain<\/strong> fulfilling ASAS criteria. HLA-B27 is positive. CRP 22 mg\/L. Sacroiliac MRI shows active bilateral sacroiliitis. RF and anti-CCP are negative. She asks whether her joint disease is related to her bowel disease. Which statement is <em>most accurate<\/em>?',\n      correct: 'She has IBD-associated SpA with both peripheral Type 1 (pauciarticular, parallels bowel activity) and axial disease (which runs independently of bowel activity); axial IBD-SpA is treated with NSAIDs cautiously and TNF inhibitors preferentially over IL-17 inhibitors',\n      opts: [\n        'She has IBD-associated SpA with both peripheral Type 1 (pauciarticular, parallels bowel activity) and axial disease (which runs independently of bowel activity); axial IBD-SpA is treated with NSAIDs cautiously and TNF inhibitors preferentially over IL-17 inhibitors',\n        'Her joint disease is coincidental and unrelated to Crohn\\'s disease; the combination of sacroiliitis, HLA-B27 positivity, and oligoarthritis confirms primary ankylosing spondylitis, which happened to develop in a patient who also has IBD',\n        'IBD-associated peripheral arthritis always parallels bowel disease activity; since her Crohn\\'s is in remission, the joint disease must represent a separate diagnosis, most likely early seronegative RA given the bilateral lower limb involvement',\n        'NSAIDs are the treatment of choice for both axial and peripheral IBD-SpA; IL-17 inhibitors should be added immediately for axial disease as they treat both the bowel inflammation and the SpA simultaneously'\n      ],\n      exp:   '<strong>IBD-associated SpA<\/strong> occurs in up to 20% of patients with Crohn\\'s or UC. It has two peripheral patterns: <strong>Type 1<\/strong> (pauciarticular, &lt;5 large joints, parallels bowel activity, self-limiting with bowel treatment) and <strong>Type 2<\/strong> (polyarticular, &ge;5 small joints, runs independently of IBD activity). <strong>Axial IBD-SpA<\/strong> (sacroiliitis, spondylitis) runs <strong>independently of bowel disease activity<\/strong> \u2014 this is the crucial distinguishing point. It is not treated by controlling the IBD. <strong>NSAIDs<\/strong> are used cautiously in IBD-SpA as they can exacerbate bowel inflammation. <strong>TNF inhibitors<\/strong> (particularly adalimumab and infliximab) are preferred \u2014 they treat both the axial SpA and the underlying IBD. <strong>IL-17 inhibitors are contraindicated<\/strong> in Crohn\\'s disease.',\n      extra: '<strong>Extra-intestinal manifestations (EIMs) of IBD<\/strong> \u2014 a high-yield exam table:<br>Joints: peripheral arthritis (Type 1 and 2) and axial SpA \u2014 most common EIM overall.<br>Eye: anterior uveitis (parallels bowel activity), episcleritis, scleritis.<br>Skin: erythema nodosum (parallels bowel activity), pyoderma gangrenosum (does not parallel).<br>Liver\/biliary: primary sclerosing cholangitis (UC &gt;&gt; Crohn\\'s; runs independently of bowel activity; 5% of UC patients; increases colorectal cancer risk in UC-PSC combination to &gt;30% at 10 years).<br><strong>Mechanism of IBD-SpA<\/strong>: bacterial antigens translocate across the damaged gut epithelium, triggering systemic inflammation in genetically susceptible (HLA-B27+) individuals. This &ldquo;gut-joint axis&rdquo; is supported by the finding that subclinical gut inflammation is detectable on ileocolonoscopy in up to 60% of AS patients without overt IBD.'\n    }\n\n  ];\n\n  var answers  = {};\n  var answered = 0;\n  var shuffled = {};\n  var done     = false;\n\n  function byId(id) { return document.getElementById(id); }\n  function gid(sfx) { return byId(NS + '-' + sfx); }\n\n  function shuffleArr(arr) {\n    var a = arr.slice(), i, j, t;\n    for (i = a.length - 1; i > 0; i--) {\n      j = Math.floor(Math.random() * (i + 1));\n      t = a[i]; a[i] = a[j]; a[j] = t;\n    }\n    return a;\n  }\n\n  function countVal(val) {\n    var k, n = 0;\n    for (k in answers) {\n      if (answers.hasOwnProperty(k) && answers[k] === val) n++;\n    }\n    return n;\n  }\n\n  function buildPips() {\n    var cont = gid('pips'), i, q, wl, wp, line, pip;\n    if (!cont) return;\n    cont.innerHTML = '';\n    for (i = 0; i < QS.length; i++) {\n      q = QS[i];\n      if (i > 0) {\n        wl = document.createElement('div'); wl.className = 'mr-pip-wrap';\n        line = document.createElement('div'); line.className = 'mr-pip-line';\n        line.id = NS + '-pl' + q.id;\n        wl.appendChild(line); cont.appendChild(wl);\n      }\n      wp  = document.createElement('div'); wp.className = 'mr-pip-wrap';\n      pip = document.createElement('div'); pip.className = 'mr-pip';\n      pip.id = NS + '-pip' + q.id;\n      pip.textContent = String(q.id);\n      wp.appendChild(pip); cont.appendChild(wp);\n    }\n  }\n\n  function build() {\n    var cont, i, q, opts, card, top, nd, meta, tagRow, tg, dl,\n        st, rule, od, ed, lb, tx, ep, epl, ept, imgSrc, imgDiv, j, oe, ls, ts;\n    cont = gid('cases');\n    if (!cont) return;\n    cont.innerHTML = '';\n    answers = {}; answered = 0; shuffled = {}; done = false;\n    if (gid('score')) gid('score').style.display = 'none';\n    buildPips();\n\n    for (i = 0; i < QS.length; i++) {\n      q    = QS[i];\n      opts = shuffleArr(q.opts);\n      shuffled[q.id] = opts;\n\n      card = document.createElement('div'); card.className = 'mr-case';\n      top  = document.createElement('div'); top.className  = 'mr-case-top';\n      nd   = document.createElement('div'); nd.className   = 'mr-num';\n      nd.textContent = q.id < 10 ? 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The spondyloarthropathies hold no ambiguity for you.'],\n      [4, 'Strong \\u2014 one distinction worth a final read before exam day.'],\n      [3, 'Solid base \\u2014 the Extra Points carry the clinical edge.'],\n      [2, 'Halfway there \\u2014 the IBD-SpA case and treatment criteria repay close study.'],\n      [0, 'SpA rewards pattern recognition. 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Uveitis 50% of cases B27+ nr-axSpA (no X-ray sacroiliitis) MRI active sacroiliitis; B27 supports diagnosis HLA-B27 and the seronegative spondyloarthropathies. Prevalence of B27 positivity varies by disease and subtype.&hellip;&nbsp;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","footnotes":""},"categories":[74,24,64],"tags":[],"class_list":["post-36950","post","type-post","status-publish","format-standard","hentry","category-morning-rounds","category-neet-pg","category-orthopaedics"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Seronegative Spondyloarthropathies - atsixty<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/atsixty.com\/index.php\/neet-pg\/seronegative-spondyloarthropathies\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Seronegative Spondyloarthropathies - atsixty\" \/>\n<meta property=\"og:description\" content=\"Morning Rounds \u00b7 Seronegative Spondyloarthropathies HLA-B27 MHC Class I Ankylosing Spondylitis 90% positive Reactive Arthritis 60&#8211;80% positive Psoriatic Arthritis axial: 50&#8211;70% IBD-SpA 25&#8211;75% (axial) Acute Ant. Uveitis 50% of cases B27+ nr-axSpA (no X-ray sacroiliitis) MRI active sacroiliitis; B27 supports diagnosis HLA-B27 and the seronegative spondyloarthropathies. 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