Management of a Wasp Sting

1. First assess severity - this determines the whole approach

2. Local reaction - first aid

• Unlike honeybees, wasps do not typically leave their stinger in the skin, so there is usually nothing to scrape out. Check anyway and remove any visible stinger.
• Wash the area with soap and water or antiseptic to reduce infection risk.
• Apply a cold pack/ice wrapped in cloth for 20 minutes to reduce swelling and pain; elevate the limb if the sting is on an arm or leg.
• Oral analgesia: paracetamol or ibuprofen for pain.
• Oral antihistamine (e.g., diphenhydramine, chlorpheniramine, cetirizine) for itching, and topical hydrocortisone cream or calamine lotion for local irritation.
• Avoid scratching. Watch for signs of secondary bacterial infection over the following days - fever, spreading redness, red streaks, warmth, or worsening tenderness at the site should prompt medical review.

3. Large local reaction

• Treat as above, plus a short course of oral corticosteroids and antihistamines is often used if swelling is extensive or spreading, per allergy/dermatology practice.

4. Systemic reaction / Anaphylaxis - emergency management

1. Call for emergency help and lay the patient down (shock position, legs raised) unless breathing is compromised.
2. Intramuscular epinephrine (adrenaline) is the first-line, immediate treatment for any grade II severity reaction and above (generalized urticaria/angioedema with systemic involvement, bronchospasm, or hypotension). If the patient has a prescribed autoinjector (e.g., EpiPen), use it as soon as symptoms begin.
3. Establish IV access, give IV fluids for hypotension.
4. Give oxygen if there is respiratory distress; be prepared for airway management if there is laryngeal edema/throat tightness.
5. Adjunct therapy after epinephrine: antihistamines and systemic corticosteroids for symptomatic relief, though these are not substitutes for epinephrine.
6. Observe for several hours after treatment because biphasic reactions can occur.
7. Refer to an allergist after recovery - anyone with a systemic reaction to a wasp sting should be evaluated with skin prick testing and/or venom-specific IgE testing, and considered for venom immunotherapy, which markedly reduces the risk of a severe reaction to future stings. Patients should also be prescribed and taught to carry an epinephrine autoinjector, and avoid ACE inhibitors/beta-blockers if possible since these can worsen anaphylaxis severity or blunt response to epinephrine.

5. Special notes

• Multiple simultaneous stings can cause systemic toxic reactions (not IgE-mediated) purely from venom load - manage symptomatically and monitor for rhabdomyolysis/renal issues if stings are numerous.
• In pregnancy, management is largely the same; epinephrine should still be used for anaphylaxis since the risk to the fetus from untreated anaphylaxis is far greater than from epinephrine itself.

1. Red flags - seek urgent/emergency care now if any of these are present

• Fever, chills, or feeling generally unwell
• Rapidly spreading redness, red streaks tracking up the leg (lymphangitis)
• Increasing pain out of proportion, skin turning dusky/purple, blistering, or crepitus (crackling) - these suggest necrotizing infection and are a surgical emergency
• Swollen/tender lymph nodes in the groin
• Signs of sepsis: fast heart rate, confusion, low blood pressure
• Diabetes, immunosuppression, peripheral vascular disease, or the leg being the affected limb with pre-existing lymphedema - infection can progress faster and needs closer monitoring

2. What a clinician will typically do

• Mark the border of the erythema with a pen and note the date/time - this lets them (or you) track whether antibiotics are working over the next 24-48 hours.
• Check for a collection of pus/abscess - if there's a fluctuant, pus-filled pocket, incision and drainage is usually needed in addition to antibiotics; antibiotics alone often won't clear an abscess.
• Swab/culture the pus if drained, especially if there's concern for MRSA or if outpatient treatment fails, to guide antibiotic choice.

3. Antibiotic management (standard approach per emergency medicine/dermatology sources and current guidelines)

• Non-purulent cellulitis (redness/swelling/warmth without pus/abscess): covers strep and staph - oral cephalexin, dicloxacillin, or amoxicillin as first line. If penicillin-allergic: clindamycin or a macrolide (azithromycin/clarithromycin).
• Purulent cellulitis / pus present / abscess (your description, since there is pus): needs MRSA coverage as well - options include trimethoprim-sulfamethoxazole or clindamycin, sometimes combined with a beta-lactam, per outpatient regimens.
• Typical course: 5-14 days of oral antibiotics, reassessed at 48-72 hours for improvement.
• If not improving on oral antibiotics, systemically unwell, or infection is extensive: escalation to IV antibiotics (e.g., cefazolin or vancomycin if MRSA risk) and possible hospital admission.

4. Supportive/local care alongside antibiotics

• Keep the leg elevated to reduce swelling and help resolution.
• Cool compresses for comfort (not heat, which can worsen spread in acute infection).
• Analgesia (paracetamol/ibuprofen) for pain.
• Keep the area clean and covered; avoid scratching or squeezing the pus site yourself - let a clinician assess and drain it properly if an abscess is confirmed.
• Monitor for the "getting worse before better" phenomenon in the first 1-2 days of antibiotics, but any rapid worsening should prompt re-evaluation.

5. Follow-up

• Reassess within 2-3 days to confirm the antibiotic is working (less redness, less swelling, no new pus).
• If there's recurrent or unusually severe infection from an insect sting, especially with lymphangitic spread, some clinicians will also check blood glucose (diabetes predisposes to skin infections) and consider tetanus status if the skin was broken.

Management Plan: Wasp Sting Complicated by Secondary Bacterial Cellulitis

Step 1 - Triage / Assess Severity First

• Fever, rigors, feeling generally unwell
• Rapidly advancing erythema, red streaks running up the leg (lymphangitis), tender groin lymph nodes
• Pain out of proportion to appearance, skin discoloration (dusky/purple/black), blistering, crepitus/gas under the skin
• Hypotension, tachycardia, confusion (sepsis signs)
• Comorbidities: diabetes, immunosuppression, peripheral vascular disease, lymphedema of that leg

Step 2 - Clinical Assessment

• Mark and date the outer border of the erythema with a pen - lets you and the clinician objectively track spread or improvement over 24-48h.
• Examine for a fluctuant collection/abscess under the pus - this is important because pus collections need drainage; antibiotics alone will not resolve a true abscess.
• Check distal pulses, sensation, and function of the leg (rule out compartment involvement if very swollen/tense).
• Check temperature, heart rate, blood pressure as baseline vitals.

Step 3 - Investigations

• Swab/culture the pus (especially before starting antibiotics if possible) to identify the organism (usually Staphylococcus aureus including possible MRSA, or Streptococcus pyogenes) and guide therapy if it doesn't respond.
• Blood tests if systemically unwell: CBC, CRP/ESR, blood cultures if febrile, blood glucose (rule out underlying diabetes).
• Consider ultrasound of the area if an abscess is suspected but not clearly palpable, to guide drainage.

Step 4 - Source Control

• If an abscess/pus pocket is confirmed: incision and drainage is the priority intervention - antibiotics alone under-treat a true abscess.
• Send drained pus for culture and sensitivity.

Step 5 - Antibiotic Therapy

• Typical duration: 5-14 days total, reassessed at 48-72 hours for response.
• Reassess if no improvement or worsening despite 48-72h of appropriate oral antibiotics - this suggests need for IV therapy, undrained abscess, or resistant organism.

Step 6 - Supportive / Local Wound Care

• Elevate the leg to reduce swelling and promote drainage of edema.
• Cool compresses for comfort (avoid heat during active spreading infection).
• Oral analgesia (paracetamol/ibuprofen) for pain.
• Clean and cover the wound; change dressings regularly; avoid squeezing or scratching the site yourself.
• Rest and limit strenuous use of the leg until inflammation settles.

Step 7 - Monitoring and Follow-up

• Re-examine within 48-72 hours to confirm the marked erythema border is not advancing and pus/swelling is improving.
• Educate the patient/family on red-flag symptoms (see Step 1) that should prompt immediate return.
• Check tetanus immunization status if the skin was broken and status is unclear or overdue.
• If recurrent, unusually severe, or slow-resolving infection: consider underlying diabetes screening, peripheral vascular assessment, and, if there was ever a systemic allergic component to the original sting (hives elsewhere, breathing difficulty), refer for allergy work-up and venom immunotherapy discussion separately from this infection.

Step 8 - When to Admit

• Systemic toxicity/sepsis, failure of outpatient oral antibiotics, need for IV antibiotics, extensive or rapidly progressing cellulitis, immunocompromised host, inability to tolerate oral intake, or diagnostic uncertainty about necrotizing fasciitis.