Skin Infection Emergency Care: EMT Guide

Skin and Soft-Tissue Infections: Emergency Assessment and Management

Why this topic matters. A red, swollen or painful area may be minor cellulitis, but it can also be the first visible sign of sepsis, necrotising fasciitis, diabetic foot infection, toxic shock, an infected bite or a deep-space infection. EMTs must examine the whole patient, compare the local findings with systemic physiology and identify when antibiotics alone are unsafe because drainage or urgent surgery is required. Drug selection and duration must follow the Uganda Clinical Guidelines, local antibiogram, allergy history, renal function and senior clinician prescription.

1. Learning objectives

Define common skin and soft-tissue infections (SSTIs) and describe the skin barrier and routes of infection.
Differentiate cellulitis, erysipelas, abscess, infected wound, diabetic foot infection and necrotising infection.
Recognise sepsis, toxic shock, deep-space infection and necrotising fasciitis early.
Perform focused history, examination, severity assessment and safe investigations.
Explain first aid, wound care, source control, antimicrobial principles and surgical referral.
Plan nursing interventions, monitoring, prevention, patient education and discharge safety-netting.

2. What is an SSTI?

Skin and soft-tissue infections involve the epidermis, dermis, subcutaneous tissue, fascia, muscle or structures around a wound. They range from superficial impetigo and infected abrasions to abscesses, cellulitis, infected ulcers, diabetic foot infection and rapidly fatal necrotising fasciitis. Common organisms include Staphylococcus aureus, beta-haemolytic streptococci, mixed aerobic/anaerobic flora in chronic wounds, and water/animal-associated organisms after special exposures.

Infection enters through cuts, ulcers, burns, injections, surgery, bites, fungal fissures, oedema or an impaired immune barrier. Diabetes, peripheral vascular disease, lymphoedema, malnutrition, HIV, sickle-cell disease, obesity, immunosuppression and delayed presentation increase risk.

3. Classification and clinical patterns

Condition	Typical findings	Emergency concern
Impetigo/ecthyma	Superficial erosions, honey-coloured crusts or deeper punched-out ulcers	Spread, dehydration in children, post-streptococcal complications or extensive disease.
Folliculitis/furuncle/carbuncle	Pustule or tender boil centred on a hair follicle; carbuncle has multiple draining points	Abscess requiring drainage, diabetes, recurrent MRSA or systemic toxicity.
Cellulitis	Diffuse erythema, warmth, swelling and tenderness without a drainable collection	Rapid progression, lymphangitis, sepsis, facial/orbital involvement or treatment failure.
Erysipelas	Raised, sharply demarcated bright-red plaque, often with fever	Bacteraemia, facial involvement and rapid systemic deterioration.
Abscess	Localised painful, fluctuant or indurated collection, sometimes with a central point	Source control needed; deep, perianal, hand, breast, face or neck sites need specialist review.
Infected wound/ulcer/diabetic foot	Purulent drainage, malodour, increasing pain, necrotic tissue or surrounding cellulitis	Deep infection, osteomyelitis, ischaemia, amputation risk and sepsis.
Necrotising fasciitis	Rapidly worsening pain/swelling, systemic toxicity, bullae, skin anaesthesia, crepitus or necrosis	Immediate surgical emergency; do not wait for imaging or antibiotic response.

4. Triage and red flags

Send to resuscitation/urgent senior review: shock, confusion, severe pain out of proportion, rapidly spreading erythema, bullae, skin discoloration or necrosis, crepitus, severe systemic toxicity, high fever or hypothermia, tachypnoea, facial/orbital or neck swelling, perineal infection, hand infection, immunosuppression, diabetes with a foot wound, exposed tendon/bone, vascular compromise, inability to walk/use the limb or failed outpatient treatment.

Mark the edge of erythema with date/time and measure length, width and circumference.
Record pulse, blood pressure, respiratory rate, SpO₂, temperature, mental status, glucose and urine output.
Ask how fast the lesion has changed; hours rather than days strongly increases concern.

5. History taking

5.1 Lesion history

Onset, speed of spread, pain severity and pain out of proportion to appearance.
Trauma, puncture, injection, surgery, burn, ulcer, bite, tattoo, piercing or water exposure.
Purulent discharge, odour, blisters, numbness, colour change and loss of function.
Previous SSTI, abscess, resistant organisms or recent antibiotics/hospitalisation.

5.2 Host and exposure risks

Diabetes, HIV, sickle-cell disease, vascular disease, lymphoedema, malnutrition and immunosuppressive medicines.
Animal/human bite, freshwater/seawater, soil, farm or flood exposure.
Recent travel, crowding, contact sports, shared razors/towels or household boils.
Drug allergy, renal/liver disease, pregnancy, anticoagulants and tetanus-immunisation status.

6. Focused examination

General: toxic appearance, fever/hypothermia, hydration, mental status and sepsis physiology.
Inspect: site, size, colour, border, crust, ulcer, bullae, necrosis, discharge, lymphangitis and satellite lesions.
Palpate gently: warmth, tenderness, induration, fluctuance, crepitus and sensation. Do not repeatedly squeeze a lesion.
Function: range of motion, tendon/nerve function, distal pulses, capillary refill and limb compartment signs.
Search for a source: interdigital fungal infection, pressure area, IV site, diabetic ulcer, surgical wound, bite, abscess or foreign body.
Compare sides: limb circumference, temperature, sensation, pulses and progression from the last mark.

7. Differentiating cellulitis, abscess and necrotising infection

Feature	Cellulitis	Abscess	Necrotising fasciitis
Distribution	Diffuse, spreading erythema	Localised collection	Rapidly expanding, often beyond visible skin changes
Pain	Tender and proportional	Focal throbbing/tenderness	Severe or out of proportion; later anaesthesia may occur
Palpation	Warm, indurated, no clear fluctuance	Fluctuant or indurated centre	Woody induration, crepitus or tense oedema
Skin	Red and warm	Pointing, pustule or drainage	Bullae, dusky colour, ecchymosis, skin slough or necrosis
Systemic illness	May be mild or severe	Usually local unless extensive	Often toxic, hypotensive, confused or rapidly deteriorating
Definitive action	Antibiotic plan and elevation/follow-up	Incision and drainage when indicated	Immediate surgical exploration/debridement plus broad empiric therapy

8. First aid and pre-hospital care

Use hand hygiene, gloves and eye protection if blood, pus or splash is possible.
Control bleeding with direct pressure; do not pack an abscess blindly or close a dirty wound.
Cover open wounds with a sterile/non-adherent dressing; do not apply household chemicals, ash, soil, toothpaste or unprescribed antibiotics.
Elevate an infected limb when it does not worsen pain or perfusion and remove constrictive jewellery/clothing.
Check glucose in a diabetic or systemically unwell patient; give oxygen for hypoxaemia.
For suspected sepsis or necrotising infection, obtain rapid transport after calling the receiving hospital; do not delay for extensive wound cleaning.
For bites, irrigate/clean promptly, assess tetanus and rabies risk, and transfer for bite-specific management.

9. Investigations

Investigation	Use	Limitations/safety
Glucose, FBC, renal/liver function and lactate	Severity, sepsis, diabetes, organ injury and antibiotic dosing	Normal results do not exclude early necrotising infection.
Wound/pus culture and susceptibility	Guide therapy in purulent, recurrent, severe or treatment-failure infection	Obtain deep material when possible; superficial swabs may reflect colonisation.
Blood cultures	Bacteraemia, sepsis, severe cellulitis or immunocompromise	Collect safely, ideally before antibiotics if this does not delay treatment.
Ultrasound	Detect a drainable abscess or fluid collection	A negative scan does not rule out deep necrotising disease.
X-ray/CT/MRI	Gas, foreign body, deep extension, osteomyelitis or complex anatomy	Never delay emergency surgical review for imaging when necrotising infection is likely.
Probe-to-bone/vascular assessment	Diabetic foot depth, ischaemia and osteomyelitis risk	Use trained clinicians and involve surgery/vascular teams early.

10. Antimicrobial and medical management principles

Use local guidelines and the likely organism, anatomic site, severity, allergies, pregnancy, renal function and resistance pattern to choose antibiotics.
Non-purulent uncomplicated cellulitis usually needs streptococcal/MSSA-active therapy; purulent infection requires assessment for drainage and possible staphylococcal/MRSA coverage according to local data.
Severe infection, immunocompromise, perineal infection, bites, water exposure, diabetic foot infection and necrotising disease require broader specialist-directed coverage.
Take cultures when severe, recurrent, unusual, immunocompromised or not responding; narrow therapy when results permit.
Give antibiotics promptly for sepsis or suspected necrotising infection, but do not let antibiotics replace source control.
Adjust dose and interval for renal/hepatic impairment and review IV-to-oral switch daily.
Provide analgesia, glucose control, hydration and tetanus prophylaxis as indicated.

11. Abscess and source control

Assess location, depth, neurovascular status and proximity to face, hand, breast, anus, genitals, tendon or joint.
Use ultrasound or surgical review for deep/uncertain collections.
Incision and drainage is the key treatment for a drainable abscess; antibiotics alone may fail when pus remains enclosed.
Use aseptic technique, analgesia/local anaesthesia and sharps safety; send appropriate material for culture in severe/recurrent cases.
Pack or leave the wound open only when clinically indicated; arrange dressing review and clear instructions.
Facial, hand, deep neck, perirectal, breast, genital and joint-adjacent abscesses need early specialist involvement.

12. Necrotising fasciitis and toxic shock

Do not wait for skin necrosis. Severe pain out of proportion, rapidly progressive swelling, systemic toxicity, bullae, crepitus, skin anaesthesia or a tense woody limb should trigger immediate surgical consultation and resuscitation.

ABCDE, oxygen, glucose, IV access, blood tests/cultures and cautious fluid resuscitation.
Urgent surgical exploration and serial debridement are definitive; imaging must not create a dangerous delay.
Start broad empiric IV antibiotics covering streptococci, staphylococci, gram-negative organisms and anaerobes according to local protocol.
Consider toxin-suppressing therapy and IV immunoglobulin only on specialist advice.
Monitor for septic shock, acute kidney injury, rhabdomyolysis, coagulopathy, respiratory failure and limb loss.

13. Special SSTIs

13.1 Diabetic foot and chronic ulcers

Inspect footwear, pressure points, pulses, sensation, depth, odour and exposed tendon/bone.
Check glucose and vascular status; off-load pressure and avoid walking on a threatened foot.
Coordinate wound care, debridement, imaging, culture and diabetes/vascular/podiatry review.

13.2 Animal and human bites

Wash/irrigate promptly, assess tendon, nerve, vessel and joint injury, and document the animal and time.
Consider rabies post-exposure prophylaxis, tetanus and bite-specific antimicrobial therapy under national guidance.
Hand, face, genital, puncture, immunocompromised and delayed presentations need urgent review.

13.3 Periorbital, facial and neck infection

Assess vision, eye movement, proptosis, severe headache, trismus, dysphagia, drooling and airway compromise.
Urgent ophthalmology/ENT/maxillofacial review is required for orbital or deep-neck signs.

14. Nursing interventions and monitoring

Priority	Interventions	Escalate when
Sepsis/perfusion	Serial vital signs, mental status, glucose, urine output, lactate and fluid response	Hypotension, rising respiratory rate, confusion, oliguria or increasing lactate
Wound	Measure/mark erythema, assess pain, colour, drainage, odour, pulses and sensation; aseptic dressings	Rapid spread, new bullae, necrosis, disproportionate pain or neurovascular change
Antibiotic safety	Check allergy, renal function, timing, route, cultures and adverse effects; review IV need daily	Rash, anaphylaxis, diarrhoea, renal deterioration or treatment failure
Mobility/pressure	Elevate limb when appropriate, off-load diabetic foot, prevent pressure injury and falls	Increasing pain, compartment signs, inability to mobilise or ischaemia
Education	Hand hygiene, wound care, medicine adherence, no squeezing, return precautions and household hygiene	Caregiver cannot perform dressing or patient lacks follow-up access

15. Prevention

Clean and cover cuts, promptly irrigate wounds and seek care for increasing redness, pain, swelling or fever.
Manage diabetes, oedema, fungal foot disease and vascular problems; inspect feet daily.
Do not share razors, towels, needles or personal wound equipment.
Use hand hygiene, clean injection technique and appropriate PPE in healthcare settings.
Complete tetanus vaccination and follow bite/rabies prevention guidance.
Use antibiotics only when indicated and complete prescribed courses; never save or share them.

16. Discharge and referral

Outpatient care is appropriate only for a stable patient with a superficial/localised infection, reliable oral intake, no danger sign, a clear antibiotic/wound plan and accessible review.

Return immediately for fever, confusion, fainting, fast breathing, spreading redness, severe/worsening pain, bullae, black skin, reduced urine, vomiting or inability to take medicines.
Keep dressings clean and dry, wash hands before/after care and do not squeeze or lance lesions at home.
Return for wound review, dressing change, culture result, suture removal or IV-to-oral antibiotic review.
Admit or refer for sepsis, necrotising infection, deep abscess, facial/hand/perineal infection, diabetic foot, immunosuppression, failed outpatient therapy or poor follow-up support.

17. Clinical scenarios

Scenario 1 – Cellulitis. A patient has a warm, tender lower-leg plaque, stable observations and no fluctuance. The EMT marks the edge, checks diabetes and pulses, cleans the entry wound, elevates the leg and arranges clinician assessment for local antibiotic therapy and follow-up. The patient receives return precautions if the redness spreads or systemic symptoms develop.

Scenario 2 – Abscess. A painful fluctuant axillary swelling has no shock. The team avoids squeezing it in triage, gives analgesia, assesses for diabetes/immunosuppression and arranges aseptic incision and drainage, culture when indicated, wound review and antibiotic decision based on severity and local guidance.

Scenario 3 – Necrotising infection. A diabetic patient has severe thigh pain, fever, tachycardia and dusky bullae after a minor cut. The EMT treats this as a surgical emergency: resuscitation, glucose, IV access, cultures if they do not delay care, broad protocol antibiotics, urgent surgical call and rapid theatre transfer. No time is lost waiting for a scan or the skin to turn black.

18. Common errors

Calling rapidly progressive pain “simple cellulitis.”
Using topical creams or antibiotics alone for a drainable abscess.
Delaying surgery for imaging in suspected necrotising fasciitis.
Failing to assess pulses, sensation, tendon function and compartment signs.
Ignoring diabetes, HIV, malnutrition, oedema or vascular disease.
Closing a contaminated/infected wound without a source-control plan.
Giving antibiotics without allergy/renal review or microbiology follow-up.
Discharging without marking progression, review date and safety-net advice.

19. Quick revision questions

What is the difference between cellulitis, erysipelas and an abscess?
List six red flags for necrotising fasciitis.
Why is source control important?
Which SSTI sites require especially early specialist review?
What tests help assess severe or recurrent infection?
What are the first actions for a human or animal bite?
How should a diabetic foot infection be assessed?
When are antibiotics alone inadequate?
What should be monitored during IV antibiotics?
Write five discharge return precautions.

20. Key takeaways