Bursitis

Bursitis is inflammation and pathological distension of a bursa — a synovial-lined, fluid-filled sac that normally sits as a collapsed potential space between a tendon or muscle and an adjacent bony prominence, reducing friction as the two surfaces glide against each other.^[1] Bursae are classified by location (subcutaneous, subfascial, subtendinous) and by whether they normally communicate with an adjacent joint space — most, including the subacromial-subdeltoid bursa of the shoulder, do not, which matters clinically because an abnormal communication (for example, a full-thickness rotator cuff tear tracking joint fluid into the subacromial bursa) is itself a distinct diagnostic finding rather than simple bursitis.^[1]

Bursitis falls into four broad, overlapping mechanistic categories, and identifying which one is present drives the entire management plan: chronic microtraumatic (overuse) bursitis from repetitive friction or pressure over a bony prominence — by far the most common cause overall; acute traumatic or hemorrhagic bursitis from a direct blow or, spontaneously, in a patient who is anticoagulated or has a coagulopathy; inflammatory bursitis from crystal deposition disease (gout more often than pseudogout) or an inflammatory arthritis such as rheumatoid arthritis; and septic bursitis from bacterial infection, most often introduced directly through the thin overlying skin rather than by bloodstream seeding, since bursae have a limited independent blood supply.^[2]

The single most important clinical task in any patient with bursitis is distinguishing septic from aseptic (noninfectious) bursitis — the two can look similar at the bedside, but the consequence of missing an infection is serious, and the consequence of treating aseptic bursitis as though it were septic (unnecessary aspiration, unnecessary antibiotics) carries its own real risk, including introducing infection into a previously sterile bursa.^[2] Olecranon (elbow), prepatellar (knee), subacromial (shoulder), trochanteric (hip), and retrocalcaneal (heel) bursitis together account for the great majority of cases seen in primary care and pharmacy practice, and this chapter is organized around those five sites.

Subacromial-subdeltoid bursa (shoulder)

The subacromial-subdeltoid bursa is actually a paired bursal complex lying between the rotator cuff tendons and the undersurface of the acromion, deep to the deltoid muscle.^[1] It becomes symptomatic through repetitive overhead activity and subacromial impingement — as the arm abducts past roughly 75-80 degrees, the subacromial space narrows and compresses the bursa against the acromion, producing friction and irritation.^[3] Patients describe anterolateral shoulder pain, non-radiating, that worsens with overhead reaching, sometimes with warmth or a boggy sensation over the bursa on examination.^[3] Subacromial bursal fluid is also seen with a full-thickness rotator cuff tear (fluid tracks from the joint into the bursa through the tear), impingement, and reactive bursitis from underlying glenohumeral joint disease such as calcium deposition arthropathy — rotator cuff tendon pathology should always be considered alongside bursitis itself rather than assumed absent.^[1]

Normal bursae of the shoulder joint: (1) subacromial-subdeltoid bursa, (2) subscapular recess, (3) subcoracoid bursa, (4) coracoclavicular bursa, (5) supra-acromial bursa, (6) medial extension of the subacromial-subdeltoid bursa. (Hirji Z, Hunjun JS, Choudur HN. Imaging of the Bursae. J Clin Imaging Sci 2011;1:22, CC BY 3.0, Wikimedia Commons)

Olecranon bursa (elbow)

The olecranon bursa is a subcutaneous sac providing near-frictionless motion between the skin and the point of the elbow. Its superficial position is exactly why it is both the most common site of bursitis overall and the site where septic bursitis occurs most often — direct trauma or repeated leaning on the elbow provides an easy route for both mechanical irritation and bacterial inoculation.^[1][2] The occupational eponyms — "student's elbow," "miner's elbow," "draftsman's elbow" — all describe the same chronic microtraumatic mechanism: sustained or repetitive pressure on the elbow while leaning on a hard surface.^[2]

Olecranon bursitis — swelling, redness, and pain at the tip of the elbow overlying the olecranon bursa. (InjuryMap, CC BY-SA 4.0, Wikimedia Commons)

Trochanteric bursa (hip)

What is loosely called "trochanteric bursitis" is more accurately termed greater trochanteric pain syndrome, since imaging and surgical series show that true bursal inflammation is only one contributor — gluteus medius/minimus tendinopathy and iliotibial band friction at the greater trochanter are at least as important and frequently coexist.^[1] Three distinct bursae surround the greater trochanter: the trochanteric (subgluteus maximus) bursa, the largest of the three, deep to the gluteus maximus and iliotibial tract; the subgluteus medius bursa, deep to the distal gluteus medius tendon; and the subgluteus minimus bursa, beneath the gluteus minimus tendon.^[1] Patients present with lateral hip pain, often worse lying on the affected side at night, descending stairs, or after prolonged walking or standing, with tenderness maximal directly over the greater trochanter. The syndrome is associated with obesity, direct trauma, inflammatory arthritis, iliotibial band tightness, and total hip arthroplasty.^[1]

Greater trochanteric pain syndrome — inflammation involving the trochanteric bursa complex overlying the greater trochanter. (Hariadhi, CC BY-SA 4.0, Wikimedia Commons)

Prepatellar bursa (knee)

The prepatellar bursa is a tricompartmental structure lying anterior to the patella, between the skin and the patella itself.^[1] It is inflamed by repetitive kneeling — "housemaid's knee," "carpet layer's knee," "coal miner's knee" — and by direct trauma or wrestling, and can also flare with gout.^[2][1] The separate infrapatellar bursae (superficial, between the distal patellar tendon and skin — "clergyman's knee"; and deep, between the patellar tendon and tibia) and the pes anserine bursa (medial knee, beneath the conjoined sartorius/gracilis/semitendinosus tendons, aggravated by running) present similarly with anterior or medial knee swelling and should be considered alongside prepatellar bursitis when localizing knee pain, since the pes anserine bursa in particular can mimic a medial meniscal tear or medial collateral ligament injury.^[1]

Prepatellar bursitis in a patient with an occupational kneeling history (a retired concrete finisher) — the classic "housemaid's knee" presentation. (CheckDO, CC0/public domain, Wikimedia Commons)

Retrocalcaneal bursa (heel)

Two separate bursae sit near the Achilles tendon insertion: the deep retrocalcaneal bursa, between the calcaneus and the anterior Achilles tendon, associated with reactive arthritis, psoriatic arthritis, ankylosing spondylitis, and calcaneal fracture; and a second, more superficial bursa between the Achilles tendon and the overlying skin, typically inflamed by poorly fitting or overly rigid heel counters on footwear.^[1] When superficial retrocalcaneal bursitis occurs together with Achilles tendinopathy and a prominent posterosuperior calcaneal bone spur, the combination is termed Haglund syndrome.^[1]

• An occupation or hobby involving sustained or repetitive pressure over a bony prominence — kneeling (flooring, carpet-laying, gardening, religious practice), leaning on the elbows (drafting, certain manual trades), or repetitive overhead reaching.
• Participation in a sport with a repetitive mechanical loading pattern relevant to a specific bursa — running and cycling (pes anserine), wrestling and volleyball (prepatellar), throwing and swimming (subacromial), and distance running (trochanteric/greater trochanteric pain syndrome).
• Obesity — a specific risk factor for greater trochanteric pain syndrome.^[1]
• Direct trauma or a single forceful blow to a bursa-bearing area.
• Anticoagulant use or an underlying coagulopathy — predisposes to acute hemorrhagic bursitis, including spontaneous cases.^[2]
• Gout or another crystal deposition disease, or an inflammatory arthritis such as rheumatoid arthritis — predisposes to inflammatory bursitis and to acute flares presenting as an acutely swollen, red, painful bursa.^[2]
• Diabetes mellitus, chronic corticosteroid use, alcohol use disorder, chronic kidney or liver disease, or another cause of immunosuppression — the dominant risk factors for septic bursitis specifically, and a reason to lower the threshold for aspiration in these patients.
• A skin breach near a bursa — an abrasion, laceration, insect bite, or a recent bursal aspiration or injection itself — providing a direct route for bacterial inoculation, since septic bursitis is usually caused by direct inoculation rather than bloodstream spread.^[2]
• Poorly fitting or overly rigid footwear — a specific risk factor for retrocalcaneal bursitis and Haglund syndrome.^[1]
• Total hip arthroplasty — an association with greater trochanteric pain syndrome.^[1]
• Older age, through a combination of cumulative mechanical wear, higher rates of relevant comorbidity (diabetes, osteoarthritis, degenerative rotator cuff disease), and total joint arthroplasty.

History and examination

Characterize onset (acute versus gradual), any preceding trauma or unusual repetitive activity, occupation and hobbies, and screen specifically for the red-flag features above — fever, disproportionate pain, spreading erythema/warmth, a skin breach, and diabetes/immunosuppression. Examine the affected bursa for size, warmth, erythema, and fluctuance, and check range of motion of the adjacent joint — bursitis, unlike true joint pathology, typically preserves active and passive range of motion, though pain may limit the extremes of movement. For subacromial bursitis, pain reproduced by resisted abduction of the arm beyond 75-80 degrees supports the diagnosis, though rotator cuff tendon pathology should also be assessed for, since the two frequently coexist.^[3]

Distinguishing septic from aseptic bursitis

^[2][4]

Blood testing

A complete blood count with differential, CRP, and/or ESR are reasonable when septic or inflammatory bursitis is suspected, but a normal white cell count and normal inflammatory markers do not rule out septic bursitis — no laboratory test alone has adequate sensitivity and specificity to substitute for bursal fluid analysis when genuine diagnostic uncertainty remains.^[2] Check a blood glucose to screen for undiagnosed diabetes, and blood cultures in an immunocompromised or systemically unwell patient.

Bursal aspiration

Aspirate whenever meaningful diagnostic uncertainty remains after history, examination, and available blood work — particularly whenever septic bursitis is a real possibility.^[2] Do not aspirate a clearly aseptic, mechanical bursa on clinical grounds — aspiration of clearly aseptic microtraumatic bursitis is not recommended, since it adds a genuine risk of introducing infection (iatrogenic septic bursitis) without diagnostic benefit.^[2]

Aspirate before starting antibiotics whenever possible — prior antibiotic exposure reduces the chance of isolating the causative organism on culture.^[2] Use an 18- to 22-gauge needle and the Z-track technique — pulling the overlying skin horizontally before advancing the needle into the bursa — to reduce both post-aspiration fluid leakage and the risk of introducing skin flora into the bursal sac.^[2] Send aspirated fluid for cell count with differential, Gram stain, culture, glucose, and crystal analysis.

^[2]

Imaging

Bursitis is usually a clinical diagnosis, and imaging is not routinely required.^[1] Point-of-care ultrasound is the preferred initial imaging test when imaging is genuinely needed — it distinguishes a distended bursa from cellulitis or a joint effusion, can guide aspiration, and (with colour Doppler) helps separate inflamed from quiescent bursal fluid.^[2][5] Plain radiographs are reasonable after recent trauma, or when a retained foreign body, calcification, bony spur (e.g., a Haglund deformity), or fracture is suspected.^[2] Reserve MRI for situations where aspiration has failed or is not feasible and septic bursitis remains a real concern, for suspected concomitant rotator cuff or tendon pathology, or when symptoms fail to resolve with conservative therapy and a labral or intra-articular process is suspected with no osteoarthritis on x-ray — order it selectively rather than as an initial test.^[2][5]

• Relieve pain and reduce bursal swelling.
• Restore full, comfortable range of motion and function of the adjacent joint.
• Correctly distinguish septic from aseptic bursitis before choosing a treatment path — this single decision point determines almost everything that follows.
• Treat septic bursitis promptly and adequately, with source control (aspiration, and drainage or bursectomy if needed) plus an appropriate antibiotic course.
• Avoid iatrogenic harm — do not aspirate a clearly aseptic bursa, and never inject corticosteroid into a bursa that could be infected.
• Identify and treat an underlying inflammatory cause (gout, rheumatoid arthritis) when present, rather than treating only the local bursal swelling.
• Identify and modify the repetitive mechanical cause to prevent recurrence.
• Avoid unnecessary imaging, unnecessary antibiotics, and unnecessary corticosteroid injections in straightforward aseptic bursitis.

• Activity modification — avoid or reduce the specific repetitive movement, pressure, or position that provoked the bursitis; this is the single most important step in both initial treatment and preventing recurrence.
• Ice — applied intermittently (e.g., 15-20 minutes several times daily) in the acute phase, particularly for acute traumatic/hemorrhagic bursitis.^[2]
• Protective padding — an elbow pad for olecranon bursitis, a knee pad for prepatellar bursitis, or equivalent padding for any superficial bursa exposed to repeated direct pressure.
• Compression wrap — a light compressive dressing or elastic bandage can help reduce and control swelling; avoid wrapping tightly enough to impair distal circulation.
• Elevation and relative rest — particularly useful for acute traumatic/hemorrhagic bursitis with significant swelling that interferes with function; aspiration may shorten the duration of symptoms in this specific situation.^[2]
• Structured exercise/physical or athletic therapy — a graded strengthening and stretching program is core therapy, not merely an adjunct, for subacromial bursitis (rotator cuff and scapular stabilizer strengthening) and greater trochanteric pain syndrome (hip abductor strengthening, iliotibial band stretching); it restores the mechanical function that reduces ongoing bursal irritation.^[5][1]
• Footwear modification — a softer or differently shaped heel counter, or a heel lift, for retrocalcaneal bursitis and Haglund syndrome.
• Weight management — a relevant modifiable factor specifically for greater trochanteric pain syndrome.^[1]
• Do not routinely aspirate a clearly aseptic, microtraumatic bursa — reserve aspiration for genuine diagnostic uncertainty, significant symptom-limiting swelling, or suspected infection; unnecessary aspiration of an aseptic bursa is a real, if uncommon, cause of iatrogenic septic bursitis.^[2]
• Surgical referral — for persistent or recurrent bursitis, or a bursa whose size interferes meaningfully with function despite adequate conservative and (where appropriate) injection therapy, refer for bursectomy; an endoscopic approach has a lower complication rate than an open approach where available.^[2]

Pregnancy

Favor non-pharmacologic measures throughout pregnancy — activity modification, ice, and padding carry no fetal risk. Preferred analgesic acetaminophen. Avoid NSAIDs from approximately 20 weeks of pregnancy onward Health Canada has confirmed a risk of fetal renal impairment and low amniotic fluid (oligohydramnios) with NSAID use from about 20 weeks, and NSAIDs are contraindicated in the third trimester (beyond 28 weeks) for this reason.^[9] Corticosteroid injection pregnancy-specific safety data for intrabursal corticosteroid injection are limited; reserve for genuinely disabling symptoms that have not responded to conservative measures, using the lowest effective dose. Treat suspected septic bursitis in pregnancy promptly — do not delay aspiration or antibiotics; choose a beta-lactam (a penicillin or cephalosporin) as first-line antibiotic therapy, since these are generally preferred and considered compatible throughout pregnancy, and avoid sulfamethoxazole-trimethoprim close to term given a theoretical risk of neonatal kernicterus.

Breastfeeding

Acetaminophen and ibuprofen are considered compatible with breastfeeding. Cloxacillin, cephalexin, and clindamycin at standard doses are also considered compatible; sulfamethoxazole-trimethoprim is generally avoided in the first month postpartum, particularly with a jaundiced, ill, stressed, premature, or glucose-6-phosphate dehydrogenase (G6PD)-deficient infant, given a theoretical kernicterus risk.

Pediatrics

Mechanical bursitis is uncommon in children outside prepatellar bursitis from kneeling or sports, but septic bursitis does occur and should be considered with the same seriousness as in an adult — a child with a swollen, warm, painful bursa and fever needs prompt assessment and, in most cases, aspiration before antibiotics.^[2] Dose antibiotics by weight per a pediatric dosing reference, and avoid sulfamethoxazole-trimethoprim in an infant under 2 months of age. Distinguish bursitis from septic arthritis of the adjacent joint on examination — bursitis, unlike septic arthritis, typically preserves passive range of motion of the joint itself — since the two require different management and septic arthritis is a surgical emergency.

Older adults

Greater trochanteric pain syndrome and subacromial bursitis, often together with degenerative rotator cuff disease, become more common with age, and comorbid diabetes and immunosuppression are more prevalent — maintain a lower threshold to consider and rule out septic bursitis in this group. Prefer a topical NSAID or acetaminophen over an oral NSAID where possible, given higher baseline gastrointestinal, renal, and cardiovascular risk with systemic NSAID use in older adults; if an oral NSAID is genuinely needed, use the lowest effective dose for the shortest duration.

Renal and hepatic impairment

Avoid or dose-reduce NSAIDs in significant renal impairment. Adjust cephalexin, sulfamethoxazole-trimethoprim, and vancomycin doses for reduced renal function, and monitor vancomycin levels and renal function closely; cloxacillin and clindamycin generally require no specific renal dose adjustment. Reduce the acetaminophen total daily dose in significant hepatic impairment.

For aseptic bursitis managed conservatively, arrange follow-up in 1-2 weeks to confirm improvement in pain, swelling, and function, and to reinforce activity modification; symptoms that fail to improve over 2-4 weeks warrant reassessment (see Treatment Failure/Next Step) rather than simply continuing the same plan indefinitely. If an intrabursal corticosteroid injection was given, monitor the injection site for skin atrophy or depigmentation and for any sign of new infection (increasing pain, erythema, warmth, or fever) in the days following injection — a post-injection flare of pain in the first 24-48 hours is common and does not by itself indicate infection, but new or worsening signs beyond that window should prompt reassessment.

For septic bursitis, arrange reassessment within 24-48 hours of starting antibiotics, particularly if managed as an outpatient with oral therapy — treatment failure with oral antibiotics alone has been reported in roughly 39-50% of cases, so a low threshold to escalate to intravenous therapy or hospitalization is appropriate if the expected improvement in pain, swelling, and erythema is not seen.^[2] Confirm the total antibiotic course reaches 10-14 days, and confirm final culture and sensitivity results are reviewed once available to adjust empiric therapy if needed.^[2]

At every follow-up, regardless of bursitis type, reassess whether the underlying repetitive activity or mechanical cause has actually been modified — persistence of the original cause is the most common reason for recurrence.

1. Aseptic bursitis not improving after a genuine 2-4 week trial of activity modification, padding, and topical/oral NSAID therapy: re-examine specifically for the red-flag features of septic bursitis before proceeding, since a missed infection is the most consequential reason for apparent "treatment failure."
2. Once septic bursitis has been re-excluded, consider intrabursal corticosteroid injection for a refractory aseptic microtraumatic bursa, or aspiration plus injection for an inflammatory (gout/rheumatoid arthritis) flare.
3. Suspected septic bursitis in which aspiration has not yet been performed: aspirate before continuing or escalating antibiotic therapy whenever feasible, to guide culture-directed treatment.
4. Septic bursitis not improving on oral antibiotics at 24-48 hours: escalate to intravenous therapy and hospitalization rather than simply extending the oral course, and reconsider culture results for a resistant organism (e.g., MRSA).
5. Persistent or recurrent bursitis of any type despite an adequate nonpharmacologic trial and, where appropriate, one corticosteroid injection: refer for surgical bursectomy — endoscopic bursectomy is preferred over open where available, given its lower complication rate.
6. A corticosteroid injection that produced no meaningful benefit, or that caused a complication (skin atrophy, depigmentation, suspected secondary infection): do not simply repeat the injection into the same bursa — reassess the diagnosis and consider whether an underlying tendon, joint, or inflammatory process was missed.
7. Persistent swelling or pain that never fits the expected pattern of simple bursitis, especially in a patient 40 years or older or with constitutional symptoms: broaden the differential to include a joint process, cellulitis, or, rarely, a soft tissue tumour, and image or refer accordingly.

• Aspirating a bursa that is clearly aseptic and mechanical "just to be sure," creating a real risk of iatrogenic septic bursitis rather than a diagnostic benefit.
• Injecting corticosteroid into a bursa before genuinely excluding infection — this is an absolute contraindication, not a relative one.
• Treating a normal white cell count or normal inflammatory markers as ruling out septic bursitis — neither does.^[2]
• Ordering an MRI as the first investigation for shoulder or other bursitis rather than starting with conservative management, and reserving ultrasound (and MRI only if that fails) for genuine diagnostic uncertainty.^[5]
• Starting antibiotics for suspected septic bursitis before aspiration when aspiration is feasible, which reduces the chance of identifying the causative organism.^[2]
• Managing confirmed or strongly suspected septic bursitis with oral antibiotics and no planned early reassessment, despite a reported 39-50% oral-treatment failure rate.^[2]
• Reaching for an intrabursal corticosteroid injection as first-line therapy for straightforward aseptic microtraumatic bursitis, rather than reserving it for a genuinely refractory case — high-quality evidence of benefit in this setting is lacking.^[2]
• Repeating corticosteroid injections into the same bursa on a recurring basis instead of addressing the underlying repetitive mechanical cause or referring for definitive (surgical) management.
• Missing an underlying gout, pseudogout, or rheumatoid arthritis flare by treating every case as simple overuse bursitis without considering or testing for a crystal or inflammatory cause.
• Promising a durable, lasting result from a single trochanteric corticosteroid injection — the evidence supports real short-to-medium-term benefit, not a durable long-term fix, and rehabilitation exercise remains necessary alongside it.^[7][8]

How to use this table: doses are adult doses and require patient-specific confirmation, including renal/hepatic adjustment. Select any drug name to open its complete Pharmasist Drug Database page.

NSAIDs and Analgesics — Aseptic and Inflammatory Bursitis

Doses below are adult doses and require patient-specific confirmation, including renal/hepatic adjustment.

Intrabursal Corticosteroid Injection and Local Anesthesia

Practitioner-administered. Absolute contraindication if septic bursitis has not been confidently excluded. Reserve for refractory aseptic bursitis after an adequate conservative trial, or for an acute inflammatory (gout/rheumatoid arthritis) flare once infection is excluded.

Empiric Oral Antibiotics — Septic Bursitis (Mild-Moderate, Immunocompetent)

Aspirate before starting antibiotics whenever feasible. Empiric coverage should target Staphylococcus aureus (responsible for roughly 80-85% of septic olecranon/prepatellar bursitis) and Streptococcus species; adjust to culture and sensitivity results once available. Total duration is typically 10-14 days.

Intravenous Antibiotics — Severe Disease, Hospitalization, or MRSA Risk