Difference between delayed and primary closure of wound
wound closure AND delayed primary closure
primary wound closure delayed primary closure definition wound management
| Feature | Primary closure | Delayed primary closure |
|---|---|---|
| Also called | Immediate closure | Tertiary closure |
| Timing | Wound edges are approximated and sutured at the initial treatment, usually immediately after cleaning and debridement. | Wound is initially left open after cleaning, irrigation, and debridement; it is closed later, commonly after about 3-5 days, if it remains clean and shows no infection. |
| Best suited for | Clean, fresh wounds with viable tissue, good blood supply, minimal contamination, and no established infection. | Contaminated, dirty, traumatic, crushed, or older wounds where immediate closure may trap bacteria or devitalized tissue. |
| Purpose | Fast healing, less scarring, and earlier restoration of function. | Allows drainage, repeated inspection, further debridement, and observation for infection before closure. |
| Healing | Usually heals by primary intention. | Initially managed open, then heals after suturing by primary intention once safe to close. |
| Cosmesis and recovery | Generally better cosmetic result and quicker healing. | Often slower and may leave a less favorable scar than immediate primary closure, but can lower the risk of closing an infected wound. |
| Main risk | Infection or abscess if a contaminated wound is closed prematurely. | Need for a second procedure or dressing care; closure may be deferred further if infection develops. |
- Primary closure: a clean surgical incision or a fresh clean laceration after adequate irrigation.
- Delayed primary closure: a heavily contaminated laceration, dirty crush injury, or selected contaminated abdominal/stoma wounds.
How do I decide which wounds need delayed closure?
traumatic wounds AND delayed primary closure
delayed primary closure contaminated traumatic wound clinical guidance
Choose delayed primary closure if the wound has one or more of these features
- Heavy contamination: soil, feces, stagnant water, organic material, saliva, or foreign material that cannot be fully removed.
- Crushed, ragged, or devitalized tissue: bruised, poorly perfused, necrotic, or extensively contused wound edges.
- Late presentation, particularly if combined with contamination or tissue damage. Time alone is not an absolute rule, but it increases concern in a high-risk wound.
- Puncture wounds, especially plantar punctures, since they are deep and difficult to irrigate and assess adequately.
- Established or suspected infection: pus, spreading redness, warmth, increasing pain, foul discharge, fever, or cellulitis. Do not simply close these later without reassessment and source control.
- High-risk host factors: diabetes, immunosuppression, severe vascular disease, or poor circulation.
- Uncertain wound bed: retained foreign body, inadequate exploration, questionable viability of tissue, or concern for ongoing contamination.
Practical decision rule
- Can I thoroughly irrigate, explore, and remove devitalized tissue?
- Is the tissue viable and well perfused?
- Is contamination low enough that closing it will not seal bacteria inside?
- Is there no infection, retained foreign body, deep structural injury, or bite-specific concern?
- Does the patient have factors that markedly increase infection risk?
- If the answer is broadly yes, primary closure can be considered.
- If there is significant uncertainty or infection risk, leave it open after irrigation/debridement, dress it, and review in about 3-5 days for possible delayed primary closure. This is consistent with SAEM wound-management guidance.
Do not treat it as a simple delayed-closure wound if there is
- Exposed tendon, bone, joint, nerve, or vessel
- Loss of sensation, weak pulse, impaired movement, or uncontrolled bleeding
- Open fracture or suspected joint penetration
- High-pressure injection injury
- Deep hand injury, major facial wound, or large tissue loss
- Animal or human bite, especially on the hand
- Rapidly spreading redness, systemic illness, or necrosis
How should I assess and irrigate a contaminated wound?
traumatic wound irrigation AND systematic review
traumatic laceration wound assessment irrigation exploration guidance
https://www.merckmanuals.com/professional/injuries-poisoning…
1. Assess before irrigating
A. Identify urgent injuries first
- Exposed bone, tendon, joint, nerve, or vessel
- Loss of distal pulse, sensation, or movement
- Suspected open fracture, joint penetration, or tendon injury
- Deep wounds over the chest, abdomen, neck, or near major vessels
- High-pressure injection injury
- Large tissue loss, severely crushed tissue, or uncontrolled bleeding
B. Take a focused history
- Mechanism and material involved: glass, metal, gravel, soil, grease, feces, seawater/freshwater, bite, or high-pressure device.
- Time since injury
- Location and depth
- Symptoms suggesting structural injury: numbness, weakness, impaired movement, severe pain.
- Comorbidities: diabetes, immunosuppression, peripheral vascular disease.
- Tetanus immunization status
C. Examine and document
- Distal pulses, capillary refill, sensation, and motor function
- Active movement of nearby joints and tendons
- Wound length, depth, direction, tissue loss, contamination, edge viability, and signs of infection
- Whether a foreign body is visible or suspected
2. Irrigate properly
- Provide adequate analgesia or local anesthesia first. Thorough irrigation is painful and poor pain control leads to inadequate cleaning.
- Use clean gloves, eye protection, good lighting, and a splash guard.
- Remove obvious loose dirt, gravel, and devitalized tissue first. Do not pull out deeply embedded objects that may be tamponading bleeding or are close to critical structures.
- Irrigate the whole wound, including recesses, while gently exposing the wound edges with forceps.
- Use a large volume of normal saline, sterile water, or clean running tap water where appropriate. For uncomplicated traumatic wounds, tap water has comparable infection outcomes to sterile fluid in available guidance.
- Use syringe irrigation with a splash guard or catheter to produce a controlled stream that dislodges debris without damaging tissue.
- Continue until all visible particulate matter is gone. A commonly cited practical volume is about 50-100 mL per cm of wound length, with more for heavily contaminated wounds. SAEM advises at least 250 mL and more until the wound is visibly clean. SAEM wound-care teaching
- Pouring antiseptics such as povidone-iodine, hydrogen peroxide, or chlorhexidine into the wound, as they may damage tissue and impair healing. They may be used cautiously on surrounding intact skin.
- Soaking a wound rather than irrigating it.
- Blindly irrigating or probing a deep puncture, sinus, or wound with an unseen base, as this can drive debris and bacteria deeper.
3. Debride and decide closure
- Clean, viable wound with no structural injury: consider primary closure.
- Uncertain cleanliness or meaningful contamination after irrigation/debridement: dress or pack as appropriate, arrange close reassessment, and consider delayed primary closure in 3-5 days.
- Still grossly contaminated, infected, or devitalized: do not close. It may require serial debridement and healing by secondary intention or specialist care.
4. Finish safely
- Apply a clean, nonadherent dressing.
- Elevate and splint an injured extremity when indicated.
- Update tetanus prophylaxis according to wound type and vaccine history.
- Give clear review instructions. Seek urgent care for increasing pain, spreading redness, pus, fever, numbness, loss of movement, or worsening swelling.
Timing of absorblable sutures
absorbable suture materials AND systematic review
absorbable suture absorption time Vicryl Monocryl PDS chromic gut surgical reference
site:ethicon.com MONOCRYL PDS absorption profile 90 180 days
- Tensile-strength retention: how long the stitch supports the wound.
- Complete absorption: when the material is broken down and disappears, often much later.
| Material | Meaningful wound support | Approximate complete absorption | Typical use |
|---|---|---|---|
| Fast-absorbing gut | 5-7 days | 21-42 days | Low-tension facial skin wounds, especially children |
| Plain surgical gut | 7-10 days | ~70 days | Oral mucosa |
| Chromic gut | 21-28 days | ~90 days | Oral mucosa, subcutaneous tissue |
| Vicryl Rapide | ~50% at 5 days; essentially none by 14 days | ~42 days | Superficial skin/mucosa needing only brief support |
| Vicryl (polyglactin 910) | ~75% at 2 weeks; ~40% at 3 weeks | 56-70 days | Deep dermal and subcutaneous closure |
| Monocryl (poliglecaprone 25) | about 50-60% at 1 week; 20-30% at 2 weeks | 90-120 days | Subcuticular or low-tension dermal closure |
| PDS (polydioxanone) | ~70% at 2 weeks; 50% at 4 weeks; 25% at 6 weeks | 180-210 days | Fascia or high-tension/deeper wounds requiring prolonged support |
Practical selection
- Face or low-tension superficial wounds: fast-absorbing gut or Vicryl Rapide.
- Routine buried dermal/subcutaneous sutures: Vicryl or Monocryl.
- Fascia or high-tension areas: PDS, because it retains strength much longer.
- Contaminated wounds: material choice and closure plan should be individualized. If a wound is dirty or infected, it may need delayed closure rather than simply an absorbable suture.
Create a quick reference PDF for wound closure and sutures
~/
traumatic laceration absorbable sutures AND systematic review
wound closure suture absorbable timing laceration management reference
mkdir -p "/tmp/workspace/wound-closure-quick-reference/src" "/tmp/workspace/wound-closure-quick-reference/output" && python - <<'PY' from reportlab.lib import colors from reportlab.lib.enums import TA_CENTER, TA_LEFT from reportlab.lib.pagesizes import A4 from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle from reportlab.lib.units import cm from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, KeepTogether from reportlab.pdfbase.pdfmetrics import stringWidth from reportlab.pdfbase.ttfonts import TTFont from reportlab.pdfbase import pdfmetrics from reportlab.lib.colors import HexColor out='/tmp/workspace/wound-closure-quick-reference/output/Wound_Closure_and_Sutures_Quick_Reference.pdf' PAGE_W, PAGE_H=A4 navy=HexColor('#16324F'); teal=HexColor('#0F766E'); sky=HexColor('#E7F4F4'); pale=HexColor('#F4F7F9'); ink=HexColor('#1E293B'); muted=HexColor('#52616B'); amber=HexColor('#FEF3C7'); red=HexColor('#B91C1C'); line=HexColor('#CBD5E1') styles=getSampleStyleSheet() styles.add(ParagraphStyle(name='TitleX', parent=styles['Title'], fontName='Helvetica-Bold', fontSize=19, leading=23, textColor=navy, spaceAfter=3)) styles.add(ParagraphStyle(name='Subtitle', parent=styles['Normal'], fontName='Helvetica', fontSize=8.5, leading=11, textColor=muted, spaceAfter=10)) styles.add(ParagraphStyle(name='H', parent=styles['Heading2'], fontName='Helvetica-Bold', fontSize=11.2, leading=13, textColor=navy, spaceBefore=7, spaceAfter=4)) styles.add(ParagraphStyle(name='BodyX', parent=styles['BodyText'], fontName='Helvetica', fontSize=8.25, leading=10.3, textColor=ink, spaceAfter=3)) styles.add(ParagraphStyle(name='Small', parent=styles['BodyText'], fontName='Helvetica', fontSize=7.1, leading=8.6, textColor=ink)) styles.add(ParagraphStyle(name='Tiny', parent=styles['BodyText'], fontName='Helvetica', fontSize=6.5, leading=7.8, textColor=muted)) styles.add(ParagraphStyle(name='Cell', parent=styles['BodyText'], fontName='Helvetica', fontSize=7.25, leading=8.4, textColor=ink)) styles.add(ParagraphStyle(name='CellBold', parent=styles['BodyText'], fontName='Helvetica-Bold', fontSize=7.25, leading=8.4, textColor=ink)) styles.add(ParagraphStyle(name='Alert', parent=styles['BodyText'], fontName='Helvetica-Bold', fontSize=8.2, leading=10.1, textColor=red)) def P(x, style='BodyX'): return Paragraph(x, styles[style]) def cell(x,bold=False): return P(x, 'CellBold' if bold else 'Cell') def header_footer(canvas, doc): canvas.saveState() canvas.setStrokeColor(line); canvas.setLineWidth(.45) canvas.line(doc.leftMargin, PAGE_H-1.15*cm, PAGE_W-doc.rightMargin, PAGE_H-1.15*cm) canvas.setFont('Helvetica-Bold',7); canvas.setFillColor(teal) canvas.drawString(doc.leftMargin, PAGE_H-.82*cm, 'WOUND CLOSURE & SUTURES | QUICK REFERENCE') canvas.setFont('Helvetica',7); canvas.setFillColor(muted) canvas.drawRightString(PAGE_W-doc.rightMargin, .72*cm, f'Page {doc.page}') canvas.drawString(doc.leftMargin, .72*cm, 'Educational reference only - apply local protocols and clinical judgment.') canvas.restoreState() doc=SimpleDocTemplate(out,pagesize=A4,rightMargin=1.15*cm,leftMargin=1.15*cm,topMargin=1.45*cm,bottomMargin=1.25*cm) story=[] story += [P('Wound Closure & Sutures', 'TitleX'),P('Assessment, irrigation, closure selection, and absorbable-suture timing for traumatic wounds.', 'Subtitle')] # algorithm story.append(P('1. Rapid wound assessment', 'H')) assessment=[ ['1', '<b>Stabilize:</b> direct pressure for bleeding; address emergency injuries first.'], ['2', '<b>History:</b> mechanism and contaminant, time since injury, bite/water exposure, foreign-body risk, diabetes/immunosuppression, tetanus status.'], ['3', '<b>Examine before anesthesia when possible:</b> pulses/capillary refill, sensation, motor function, active tendon/joint movement.'], ['4', '<b>Inspect under good lighting:</b> depth, tissue viability, contamination, foreign body, and injury to tendon, nerve, vessel, bone, or joint.'], ] t=Table([[cell(a,True),cell(b)] for a,b in assessment],colWidths=[.55*cm,16.45*cm],hAlign='LEFT') t.setStyle(TableStyle([('BACKGROUND',(0,0),(0,-1),sky),('VALIGN',(0,0),(-1,-1),'TOP'),('GRID',(0,0),(-1,-1),.3,line),('LEFTPADDING',(0,0),(-1,-1),4),('RIGHTPADDING',(0,0),(-1,-1),4),('TOPPADDING',(0,0),(-1,-1),3),('BOTTOMPADDING',(0,0),(-1,-1),3)])); story.append(t) story.append(Spacer(1,4)) story.append(P('<b>Urgent specialist assessment:</b> exposed tendon/bone/joint/vessel; impaired pulse, sensation, or movement; open fracture or possible joint penetration; high-pressure injection injury; uncontrolled bleeding; major tissue loss; deep wounds near major structures.', 'Alert')) story.append(P('2. Irrigate, explore, debride', 'H')) irrigation=[ '<b>Analgesia/anesthesia first:</b> enables adequate exploration and cleaning.', '<b>Explore visually:</b> control bleeding, expose the full wound under good light, remove visible particulate matter with forceps/gauze. Do not blindly probe deep wounds.', '<b>Irrigate copiously:</b> normal saline, sterile water, or clean running tap water can be used. Use syringe irrigation with a splash guard/catheter; direct flow through the entire visible wound.', '<b>Volume:</b> use enough to remove all visible debris. A practical guide is 50-100 mL/cm for contaminated lacerations; at least 250 mL is often needed, with more for heavy contamination.', '<b>Debride:</b> remove clearly devitalized tissue and persistent debris conservatively. Reassess tissue viability and wound cleanliness afterwards.', '<b>Avoid:</b> soaking instead of irrigation; hydrogen peroxide, chlorhexidine, or povidone-iodine within the wound; deep high-pressure irrigation or blind coring of puncture wounds.' ] story.append(Table([[cell('•',True),cell(x)] for x in irrigation],colWidths=[.45*cm,16.55*cm],style=[('VALIGN',(0,0),(-1,-1),'TOP'),('LEFTPADDING',(0,0),(-1,-1),2),('RIGHTPADDING',(0,0),(-1,-1),3),('TOPPADDING',(0,0),(-1,-1),1.8),('BOTTOMPADDING',(0,0),(-1,-1),1.8)])) story.append(P('3. Choose the closure strategy', 'H')) closure_data=[[cell('Strategy',True),cell('When to use',True),cell('Key point',True)], [cell('Primary closure',True),cell('Clean or rendered-clean wound; viable, well-perfused edges; no deep structural injury; low infection risk.'),cell('Immediate approximation. Best healing speed and cosmetic result when appropriate.')], [cell('Delayed primary closure',True),cell('Uncertain cleanliness or substantial infection risk after cleaning: contaminated, crushed/contused, devitalized, older high-risk wounds, or selected bites/punctures.'),cell('Irrigate and debride, leave open with suitable dressing/packing, reassess. If clean and noninfected, close in about <b>3-5 days</b>.')], [cell('Secondary intention',True),cell('Grossly contaminated despite cleaning, infected, significant tissue loss, or unsuitable for later approximation.'),cell('Leave open to heal with ongoing wound care; consider surgical review.')]] t=Table(closure_data,colWidths=[3.0*cm,8.3*cm,5.7*cm],repeatRows=1) t.setStyle(TableStyle([('BACKGROUND',(0,0),(-1,0),navy),('TEXTCOLOR',(0,0),(-1,0),colors.white),('BACKGROUND',(0,1),(-1,-1),pale),('GRID',(0,0),(-1,-1),.35,line),('VALIGN',(0,0),(-1,-1),'TOP'),('LEFTPADDING',(0,0),(-1,-1),4),('RIGHTPADDING',(0,0),(-1,-1),4),('TOPPADDING',(0,0),(-1,-1),3),('BOTTOMPADDING',(0,0),(-1,-1),3)])); story.append(t) story.append(Spacer(1,3)); story.append(P('<b>Never use time alone as the decision rule.</b> Contamination, tissue viability, anatomic site, host factors, ability to explore/irrigate, and suspected structural injury matter more.', 'BodyX')) story.append(P('4. Absorbable suture timing', 'H')) suture=[[cell('Material',True),cell('Useful support / strength retention',True),cell('Approx. absorption',True),cell('Common use',True)], [cell('Fast-absorbing gut',True),cell('5-7 days'),cell('21-42 days'),cell('Low-tension facial skin, pediatric skin closure')], [cell('Plain gut',True),cell('7-10 days'),cell('~70 days'),cell('Oral mucosa')], [cell('Chromic gut',True),cell('21-28 days'),cell('~90 days'),cell('Oral mucosa; subcutaneous tissue')], [cell('Vicryl Rapide',True),cell('~50% at day 5; none by day 14'),cell('~42 days'),cell('Short-term superficial skin/mucosa support')], [cell('Vicryl (polyglactin 910)',True),cell('~75% at 2 wk; ~40% at 3 wk'),cell('56-70 days'),cell('Buried dermal/subcutaneous approximation')], [cell('Monocryl (poliglecaprone 25)',True),cell('~50-60% at 1 wk; ~20-30% at 2 wk'),cell('90-120 days'),cell('Subcuticular or low-tension dermal closure')], [cell('PDS (polydioxanone)',True),cell('70% at 2 wk; 50% at 4 wk; 25% at 6 wk'),cell('180-210 days'),cell('Fascia or deeper/high-tension wounds')],] t=Table(suture,colWidths=[3.35*cm,5.3*cm,2.55*cm,5.8*cm],repeatRows=1) t.setStyle(TableStyle([('BACKGROUND',(0,0),(-1,0),teal),('TEXTCOLOR',(0,0),(-1,0),colors.white),('BACKGROUND',(0,1),(-1,-1),colors.white),('ROWBACKGROUNDS',(0,1),(-1,-1),[colors.white,pale]),('GRID',(0,0),(-1,-1),.3,line),('VALIGN',(0,0),(-1,-1),'TOP'),('LEFTPADDING',(0,0),(-1,-1),3),('RIGHTPADDING',(0,0),(-1,-1),3),('TOPPADDING',(0,0),(-1,-1),2.3),('BOTTOMPADDING',(0,0),(-1,-1),2.3)])); story.append(t) story.append(Spacer(1,4)); story.append(P('<b>Remember:</b> strength is lost before the suture fully absorbs. Absorption varies by product, tissue, infection, and patient factors. Do not remove buried absorbable sutures yourself.', 'BodyX')) story.append(P('5. Surface suture size and removal timing', 'H')) left=[[cell('Site',True),cell('Usual size',True),cell('Nonabsorbable removal',True)], [cell('Face',True),cell('6-0'),cell('3-5 days')], [cell('Scalp',True),cell('3-0 or 4-0'),cell('6-10 days')], [cell('Trunk',True),cell('4-0'),cell('6-10 days')], [cell('Arms / legs',True),cell('4-0'),cell('10-14 days')], [cell('Digits',True),cell('5-0'),cell('10-14 days')], [cell('Over joints',True),cell('Site-specific'),cell('~14 days')]] t=Table(left,colWidths=[5*cm,4*cm,8*cm]) t.setStyle(TableStyle([('BACKGROUND',(0,0),(-1,0),navy),('TEXTCOLOR',(0,0),(-1,0),colors.white),('ROWBACKGROUNDS',(0,1),(-1,-1),[colors.white,pale]),('GRID',(0,0),(-1,-1),.3,line),('VALIGN',(0,0),(-1,-1),'TOP'),('LEFTPADDING',(0,0),(-1,-1),4),('RIGHTPADDING',(0,0),(-1,-1),4),('TOPPADDING',(0,0),(-1,-1),2.5),('BOTTOMPADDING',(0,0),(-1,-1),2.5)])); story.append(t) story.append(P('Aftercare and safety net', 'H')) story.append(P('Clean nonadherent dressing, elevation and immobilization when indicated, tetanus prophylaxis as appropriate, and a wound check if high risk. Seek urgent review for worsening pain, spreading redness, purulent drainage, fever, numbness, loss of movement, wound separation, or increasing swelling.', 'BodyX')) story.append(Spacer(1,6)); story.append(P('<b>Sources:</b> Tintinalli’s Emergency Medicine, 9th ed., pp. 314-316; Rosen’s Emergency Medicine, 10th ed., p. 2434; Roberts and Hedges’ Clinical Procedures in Emergency, p. 754; [SAEM Basic Wound Management](https://www.saem.org/about-saem/academies-interest-groups-affiliates2/cdem/for-students/online-education/m3-curriculum/group-emergency-department-procedures/basic-wound-management); [Merck Manual wound care](https://www.merckmanuals.com/professional/injuries-poisoning/how-to-care-for-wounds-and-lacerations/how-to-cleanse-irrigate-debride-and-dress-wounds).', 'Tiny')) doc.build(story,onFirstPage=header_footer,onLaterPages=header_footer) print(out) PY
python - <<'PY' from pypdf import PdfReader p='/tmp/workspace/wound-closure-quick-reference/output/Wound_Closure_and_Sutures_Quick_Reference.pdf' r=PdfReader(p) print('exists', len(r.pages), 'pages') for i,page in enumerate(r.pages,1): text=page.extract_text() or '' print(i, len(text), text[:90].replace('\n',' | ')) PY ls -lh "/tmp/workspace/wound-closure-quick-reference/output/Wound_Closure_and_Sutures_Quick_Reference.pdf"
Wound Closure and Sutures Quick Reference
PDF Document · PDF
Inflammation and their stages
inflammation resolution AND systematic review
acute inflammation vascular cellular events stages pathology
Inflammation
Cardinal signs
- Redness (rubor): vasodilation increases local blood flow.
- Heat (calor): increased blood flow.
- Swelling (tumor): leakage of protein-rich fluid into tissues.
- Pain (dolor): mediators such as bradykinin and prostaglandins, plus pressure from edema.
- Loss of function (functio laesa): due to pain, swelling, and tissue damage.
Stages of the inflammatory response: the “5 Rs”
| Stage | What happens | Main cells/mediators |
|---|---|---|
| 1. Recognition | Tissue macrophages, mast cells, and other sentinel cells recognize microbes, foreign material, or damaged/dead cells. | Macrophages, mast cells, dendritic cells; pattern-recognition receptors |
| 2. Recruitment | Blood vessels dilate and become more permeable. Fluid, plasma proteins, and leukocytes move into the injured tissue. | Histamine, nitric oxide, prostaglandins, complement; initially neutrophils |
| 3. Removal | Leukocytes kill microbes and clear necrotic tissue and debris by phagocytosis. | Neutrophils early; macrophages later; reactive oxygen species and lysosomal enzymes |
| 4. Regulation / resolution | The inflammatory response is switched off once the stimulus is removed. Excess cells undergo apoptosis or leave via lymphatics. | Anti-inflammatory cytokines such as IL-10 and TGF-beta; lipoxins and other pro-resolving mediators |
| 5. Repair | Tissue regenerates when possible; otherwise connective tissue repair, angiogenesis, collagen deposition, and scar formation occur. | Macrophages, fibroblasts, endothelial cells, platelets |
Acute inflammation
Duration: usually hours to days
Predominant cell: neutrophil
Sequence
- Brief vasoconstriction may occur immediately after injury.
- Vasodilation causes redness and warmth.
- Increased vascular permeability allows protein-rich exudate to escape, causing edema.
- Blood flow slows, allowing leukocytes to move toward the vessel wall.
- Leukocytes undergo:
- Margination
- Rolling
- Firm adhesion
- Transmigration through the vessel wall
- Chemotaxis toward the injury
- Neutrophils phagocytose microbes and debris.
- The response resolves, forms pus/abscess, heals with scar, or progresses to chronic inflammation.
Chronic inflammation
Predominant cells: macrophages, lymphocytes, and plasma cells
- Persistent infections, for example tuberculosis or some fungal infections
- Autoimmune or hypersensitivity diseases
- Prolonged exposure to toxic substances, for example silica
- Foreign material that cannot be cleared
Hallmarks
- Ongoing inflammation
- Ongoing tissue damage
- Attempts at healing, including angiogenesis and fibrosis
Link to wound healing
Recognize -> Recruit -> Remove -> Resolve -> Repair.