USMLE Rheumatology I

• It is a complication of a chronic inflammatory condition (eg, chronic infections, inflammatory bowel disease, rheumatoid arthritis) resulting in extracellular tissue deposition of fibrils into tissues and organs.
• Patients can develop multi-organ dysfunction (eg, kidneys, liver, gastrointestinal tract).
• Treatment usually involves treating the underlying inflammatory disease.
• Colchicine is approved for both the treatment and prophylaxis of AA.

• Clinical Features: chronic back pain and stiffness that improve with activity (stretching), warm showers, and nonsteroidal agents, suggestive of inflammatory back pain.
• X-ray shows arthritis and erosions involving the sacroiliac joints.
• Incidence is highest at age 20-30, and there is a strong association with HLA-B27.
• Anterior uveitis (iritis) is the most common extraarticular manifestation of AS and occurs in 25%-40% of patients. It is characterized by inflammation of the uveal tract (iris, ciliary body, and choroid). Anterior uveitis typically presents with intense pain and photophobia in one eye.
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• Episcleritis is characterized by inflammation seen at the white of the eye, without involvement of the uveal tract.
• It is most strongly associated with rheumatoid arthritis and inflammatory bowel disease but is not associated with AS.
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• Plain x-rays of the pelvis showing sacroiliitis can confirm the diagnosis of AS.
• However, x-rays may be negative in early stages; MRI can confirm sacroiliitis in such cases.
• Fusion of the vertebral bodies with ossification of intervertebral discs (bamboo spine) also suggests the diagnosis.
• There is a strong association between HLA-B27 and AS, but whereas >90% of patients with AS have HLA-B27, only 5% of patients with HLA-B27 have AS.
• Therefore, HLA-B27 is not specific for AS and testing for it is not necessary for diagnosis.
• On the other hand, demonstrating radiographic changes of the axial skeleton is necessary for diagnosis.

• It is characterized by inflammation and pain at sites where tendons and ligaments attach to bone.
• It is commonly due to tendon or ligament stress and can manifest as acute swelling and pain.
• Examination findings include tenderness at tendon insertion sites.
• Enthesitis at the insertion of the Achilles tendon at the heel is often the most prominent presentation.
• However, enthesitis can also be seen at the costosternal junction, shoulders, elbows, hips, iliac crests, tibial tuberosities, and other locations. .
• Enthesitis may occur as an isolated disorder (eg, plantar fasciitis) but is a characteristic finding in the spondyloarthropathies such as ankylosing spondylitis (AS), psoriatic arthritis, and reactive arthritis
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• Patients with longstanding AS can develop osteopenia/osteoporosis due to increased osteoclast activity in the setting of chronic inflammation (mediated by TNF-alpha and interleukin-6).
• In addition, spinal rigidity in these patients can increase the risk of vertebral fracture, which often results from minimal trauma.
• Associated findings may include thoracic wedging and hyperkyphosis.
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• Bony metastases are much more common than primary bone tumors and the most common tumors that metastasize to bone include lung, breast, prostate, thyroid, and kidney cancers.
• Bony metastases typically cause pain that is constant and worse at night, with point tenderness on examination.
• In contrast, the pain caused by degenerative disease is typically exacerbated by exercise and relieved by rest.

• It is the most common cause of back pain.
• It is estimated that the lifetime risk of lumbosacral strain is close to 80%.
• The pain starts acutely after physical exertion, and it is concentrated in the lumbar area, usually without radiation to the thighs.
• Physical examination reveals local tenderness and contraction of the paraspinal muscles.
• A straight-leg raising test and neurologic examination are typically normal.
• Treatment includes NSAIDs and early mobilization.

• Acute pain( less than 4 wks)
• • Maintain moderate activity
• • NSAIDs or acetaminophen
• • Consider: muscle relaxants, spinal manipulation, brief course of opioids
• Chronic pain (more than 12 weeks)
• • Intermittent use of NSAIDs or acetaminophen
• • Exercise therapy (stretching/strengthening, aerobic)
• • Consider: tricyclic antidepressants, duloxetine
• Secondary prevention
• • Exercise therapy
• • Education

• Most patients with acute (less than 4-6 weeks), uncomplicated low back pain experience spontaneous resolution in the first few weeks; therefore, initial management emphasizes short-term symptomatic relief.
• Patients with acute back pain should be advised to continue moderate activity.
• Extended periods of bed rest or other significant reductions in activity are associated with prolonged pain and stiffness and should be avoided.
• Nonopioid analgesics are preferred as initial management, and a short course of nonsteroidal anti-inflammatory drugs (NSAIDs) and/or acetaminophen is adequate for most patients.

• Imaging for uncomplicated low back pain does not improve outcomes and is not recommended.
• However, patients at risk for infection, malignancy, or bony abnormalities (eg, compression fracture) may require more aggressive or specific intervention and warrant early imaging.
• These red flag features include the following:
• • Age >50
• • History of cancer
• • Constitutional symptoms (eg, fever, unexplained weight loss)
• • Nocturnal pain
• • No response to appropriate treatment
• • Significant or progressive neurologic deficits

For patients in whom multiple myeloma is suspected (eg, bone pain, anemia, hypercalcemia, kidney injury), skeletal surveys (including x-rays of chest, spine, skull, and pelvis) are preferred to a bone scan as they better detect the lytic lesions seen in multiple myeloma.

• In patients with chronic LBP, exercise has proven to be beneficial in reducing pain and improving function.
• Patients often start with a supervised exercise program that emphasizes stretching and strengthening of the back muscles.
• Aerobic exercise is also helpful. Subsequently, patients can transition to a home exercise program, which should be continued on a long-term basis. Short courses of acetaminophen or NSAIDs can be used intermittently.
• Some patients also may benefit from tricyclic antidepressants or duloxetine, but opioids, benzodiazepines, and muscle relaxants are not advised for routine use.

• They are often asymptomatic and present as a chronic, painless bulge behind the knee.
• The diagnosis is usually apparent on examination, with a soft mass in the medial popliteal space that is most noticeable with knee extension and less prominent with flexion.
• Rupture of a popliteal cyst (eg, following strenuous exercise) can cause posterior knee and calf pain, with tenderness and swelling of the calf resembling deep venous thrombosis (DVT).
• An arc of ecchymosis is often visible distal to the medial malleolus ("crescent sign").
• Ultrasound can rule out DVT and confirm the popliteal cyst.

• Epidemiology
• • Young adults
• • Turkish, Middle Eastern, or Asian descent
• Clinical findings
• • Recurrent, painful oral aphthous ulcers
• • Genital ulcers
• • Eye lesions (eg, uveitis)
• • Skin lesions (eg, erythema nodosum, acneiform lesions)
• • Vasculitis with Venous and Arterial thrombosis
• Evaluation
• • Pathergy - Exaggerated skin ulceration with minor trauma (eg, needlestick.)
• • Biopsy - Nonspecific vasculitis of different-sized vessels often involving small and medium sized vessels

• It is an alkylating agent frequently used as an immunosuppressant in systemic lupus erythematosus, vasculitis and certain cancers.
• Regarding SLE, cyclophosphamide is reserved for patients with significant renal or central nervous system problems.
• Serious side effects include acute hemorrhagic cystitis, bladder carcinoma, sterility, and myelosuppression.
• Hemorrhagic cystitis and bladder cancer are caused by acrolein, a bladder-toxic metabolite of cyclophosphamide.
• Drinking plenty of fluids, voiding frequently, and taking MESNA are all helpful in preventing these complications.

• Cochlear dysfunction: cisplatin, carboplatinand Aminoglycosides
• Optic neuritis :Ethambutol and hydroxychloroquine
• Peripheral neuropathy: phenytoin, isoniazid, vincristine, heavy metals, and chronic alcoholism
• Digital vasospasm (Raynaud's phenomenon): beta blockers and ergotamine.
• Thyroid Dysfunction: Amiodarone and lithium
• Gout: Cyclosporine

• This condition is often referred to as anserine bursitis, but most patients do not have true inflammation in the bursa, and multiple regional structures can contribute to the pain.
• The pes anserinus is formed by the conjoined tendons of gracilis, sartorius, and semitendinosus.
• The anserine bursa is located anteromedially over the tibial plateau, just below the joint line of the knee and deep to the pes anserinus.
• PAPS can be caused by an abnormal gait, overuse, or trauma.
• Localized pain is typical over the anteromedial tibia and is often exacerbated by pressure from the opposite knee while lying on the side.
• Examination shows a well-defined area of tenderness over the medial tibial plateau just below the joint line.
• Diagnosis is primarily based on clinical features, although x-ray can exclude concurrent osteoarthritis of the knee.
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• CTS is caused by compression of the median nerve as it passes deep to the flexor retinaculum in the wrist.
• Conditions that cause swelling of the flexor tendons or fibrosis or edema of the surrounding soft tissues can reduce the available space for the median nerve and lead to compressive neuropathy.
• Risk factors:
• • Obesity
• • Pregnancy
• • Diabetes
• • Hypothyroidism
• • Rheumatoid arthritis
• Clinical presentation:
• • Pain & paresthesias in median nerve distribution (first 3 and 1/2 digits)
• • Positive Phalen & Tinel tests
• • Severe disease: Weakness of thumb abduction & opposition, atrophy of thenar eminence
• Confirmatory test:
• • Nerve conduction studies
• Treatment:
• • Most patients with mild CTS will respond to conservative measures, including nocturnal wrist splinting, which holds the wrist in a neutral position and prevents excessive flexion during sleep.
• • Glucocorticoid injection
• • Surgery for severe or refractory symptoms

• Pain/tenderness and numbness/decreased sensation in a median nerve distribution (eg, first 3 and 1/2 digits).
• The pain can radiate to the palm, wrist, and forearm, but because the palmar branch of the median nerve enters the hand outside the carpal tunnel, sensation in the proximal part of the palm (eg, thenar eminence) is intact.
• In advanced cases, denervation atrophy in the median nerve distribution, including thenar atrophy, can be seen, with weakness of the muscles of the thenar eminence (eg, weakness in thumb abduction and opposition).
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• It is an anatomic space in the wrist defined by the carpal bones and the transverse carpal ligament.
• It contains the median nerve along with the tendons of the flexor digitorum profundus, flexor digitorum superficialis, and flexor pollicis longus.

• During examination, tapping over the median nerve at the wrist (Tinel sign) or holding the wrists in extreme flexion with the dorsum of the hands pressed together (Phalen test) can often reproduce the symptoms.
• However, if the diagnosis is uncertain (or severe symptoms prompt consideration for surgery), CTS can be confirmed with nerve conduction studies, which will show slowing in the median nerve at the wrist.

• Affects people older than 50 years.
• There is typical history of chronic neck pain.
• Limited neck rotation and lateral bending due to osteoarthritis and secondary muscle spasm.
• Sensory deficit due to osteophyte-induced radiculopathy and isolated sensory abnormalities are associated with good prognosis.
• Typical radiographic findings include bony spurs and sclerotic facet joints.
• Interestingly, such 'osteoarthritic' changes are common in asymptomatic patients older than 50 years of age; therefore, specificity of these findings are low.
• Other findings during cervical spondylosis may include narrowing of the disk spaces and hypertrophic vertebral bodies

• Pathogenesis involves decreased proprioception, pain, and temperature perception, which can occur due to diabetes, peripheral nerve damage, syringomyelia, spinal cord injury, vitamin B12 deficiency, or tabes dorsalis.
• As normal neurologic input is lost, patients unknowingly traumatize their weight-bearing joints. This causes secondary degenerative joint disease, joint deformation, and functional limitation
• Management of a Charcot joint involves treating the underlying disease and providing mechanical devices (eg, special shoes) to assist in weight bearing and decrease further trauma.

• It is a condition that classically affects new mothers who hold their infants with the thumb outstretched (abducted / extended).
• This condition is caused by inflammation of the abductor pollicis longus and extensor pollicis brevis tendons as they pass through a fibrous sheath at the radial styloid process.
• Tenderness can typically be elicited with direct palpation of the radial side of the wrist at the base of the hand
• Additionally, the Finkelstein test, which is conducted by passively stretching the affected tendons by grasping the flexed thumb into the palm with the fingers, elicits pain.

• Trigger Thumb results in pain over the palmar aspect of the first metacarpophalangeal joint and locking of the thumb in flexion.
• Scaphoid fractures typically occur during forceful hyperextension of the wrist as may occur in a fall on an outstretched hand. Pain typically localizes to the anatomic snuffbox.

• It is an autoimmune condition that is 6 times more common in women.
• In its most classic form, it causes a proximal extensor muscle inflammatory myopathy and characteristic cutaneous findings (eg, violaceous poikiloderma over various regions of the body).
• On the face, the eruption is most often accompanied by periorbital edema and is known as the heliotrope sign.
• On the chest and lateral neck it is called the shawl sign. On the knuckles, elbows, and knees it is referred to as Gottron's sign.
• Violaceous, slightly scaly papules overlying the joints are known as Gottron's papules; these are pathognomonic for dermatomyositis.
• There is elevated creatine phosphokinase (CPK) that is generally 10 times the upper limit of normal.
• Classic autoantibodies associated with dermatomyositis are anti Jo-1 (antisynthetase antibody) and anti-Mi-2 (against helicase ).

• Internal malignancies are more common in patients with dermatomyositis ( more than 15% of adult patients) compared to the general population.
• Most common malignancies are ovarian, lung, pancreatic, stomach, or colorectal cancers, and non Hodgkin lymphoma.
• Regular, age-appropriate cancer screening is essential in these patients.

• FM presents most commonly in young to middle-aged women with widespread pain, fatigue, and cognitive/mood disturbances.
• Patients tend to have a fairly normal physical examination except for point muscle tenderness in areas such as the mid trapezius, lateral epicondyle, costochondral junction in the chest, and greater trochanter.
• FM has no specific diagnostic laboratory findings. Revised 2010 American College of Rheumatology criteria suggest using the widespread pain index and symptom severity scale, rather than trigger points, for diagnosis.
• The index and scale better emphasize cognitive problems, fatigue, and severity of somatic symptoms.

• Initial management of FM involves a multidisciplinary approach including patient education about FM, regular aerobic exercise, and good sleep hygiene.
• Education requires validating that FM is a benign condition with a favorable prognosis.
• Although patients may complain of increased short-term pain during or after activity, a regular exercise program (eg, aerobic conditioning, strength training, stretching) improves long-term pain.
• Water exercises also can greatly reduce the pain.
• Medications (eg, tricyclic antidepressants) are reserved for patients failing initial measures
• Serotonin and norepinephrine reuptake inhibitors (eg, duloxetine, milnacipran) and pregabalin are alternate therapies that may be useful for patients not responding to tricyclic antidepressants

• It occurs in runners.
• The disorder is not a true neuroma but is a mechanically induced neuropathic degeneration of the interdigital nerves that causes numbness, aching, and burning in the distal forefoot from the metatarsal heads to the third and fourth toes.
• The symptoms are worsened by walking on hard surfaces and wearing tight or high-heeled shoes.
• On examination, squeezing the metatarsal joints will cause pain on the plantar surface of the foot along with crepitus between the third and fourth toes (Mulder sign).
• Treatment involves metatarsal support with a bar or padded shoe inserts to decrease pressure on the metatarsal heads. Surgery is usually reserved for patients who fail conservative treatment.

• Continued use of fluoroquinolone can lead to rupture of the tendon.
• Risk factors include age more than 60, female, normal body mass index, concurrent oral corticosteroid use, and history of organ transplant.
• Tendinopathy most commonly involves the Achilles tendon but can also occur in the rotator cuff, hand, biceps, thumb, and other tendon sites.
• Pain/tenderness is present 2-6 cm above the posterior calcaneus in Achilles tendinopathy.
• Patients should stop the drug at the onset of symptoms, avoid exercise and/or use of the affected area, and seek medical care for symptom evaluation and changing to a non-fluoroquinolone antibiotic.

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• It is a chronic vasculitis affecting the medium and large vessels and is characterized by a variety of localized, systemic, and ocular manifestations.
• Physical examination may show diminished pulses and/or bruits on auscultation of the axillary, brachial, or femoral arteries and over the supraclavicular and/or carotid areas.
• Anterior ischemic optic neuropathy is the most common ocular manifestation and is detected on funduscopy by the presence of a swollen and pale disc with blurred margins.
• Visual syndromes with vision loss are the most dreaded complication of GCA, and blindness can develop in up to 25%-50% of untreated patients.
• As giant cell arteritis can involve the branches of aorta, an aortic aneurysm is a well-known complication.
• For this reason, patients should be followed with serial chest x-rays

• Gonococcal septic arthritis may present with asymmetric polyarthralgias (most often associated with tenosynovitis and painless vesiculopustular lesion) or an isolated purulent mono or oligoarthritis. In some patients, asymmetric polyarthralgias may precede purulent monoarthritis.
• Vesiculopustular lesions of disseminated gonococcal infection tend to number from two to ten and may be dismissed as furuncles or pimples. Fevers and chills may be present.
• Roughly 75% of cases are "silent," meaning that the preceding genitourinary or pharyngeal infection goes unnoticed.
• Purulent arthritis in a sexually active individual is gonococcal arthritis until proven otherwise.

• Synovial fluid white blood cell count is about 50,000/mm(slightly lower than other septic arthritides).
• Gram stain of the synovial fluid (positive in 25% of cases), blood cultures (positive in 20%-50% of cases), and genital/pharyngeal mucosal nucleic acid amplification tests (positive in 90% of cases) are used to confirm the diagnosis.
• Treatment is ceftriaxone or cefotaxime.

• Underlying joint disorders (eg, gout, pseudogout, osteoarthritis) increase the risk for secondary joint infection.
• In patients with crystal-induced arthritis (eg, gout), the presence of crystals alone does not rule out septic arthritis as these can be present in synovial fluid between attacks.
• If the Gram stain is positive and joint fluid white cell count is >50,000/cu mm, the patient should be started on empiric antibiotics until culture results are known.
• If crystals are present, the fluid is nonpurulent, and Gram stain is negative, the patient may be managed as for a standard gout flare.
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• Gout is characterized by recurrent attacks that typically develop overnight or early in the morning, reaching maximum intensity within 12-24 hours.
• Increased risk:
• • Medications (Eg, diuretics,Cyclosporine, low-dose aspirin , Allopurinol )
• • Surgery, trauma, recent hospitalization
• • Volume depletion
• • Diet: High-protein (meat, seafood), high-fat, fructose or sweetened beverages
• • Heavy alcohol consumption
• • Underlying medical conditions (eg, hypertension, obesity, chronic kidney disease, organ transplant)
• Decreased risk:
• • Dairy product intake
• • Vitamin C (more than 1500 mg/day)
• • Coffee intake (more than 6 cups/day)