Why is my yellow jacket sting still swelling at 36 hours?

That is normal. Venom swelling can keep increasing for up to 48 hours after a sting (Mayo Clinic; WebMD; Seattle Children's). If the swelling stays under about 4 inches across and is confined near the sting site, no escalation is needed. If it exceeds 4 inches or involves an entire limb — that is a large local reaction, uncomfortable but typically not dangerous, and you should see a clinician within 24 hours.

My whole arm or leg is swollen from a sting — is that anaphylaxis?

No. Whole-limb swelling is a large local reaction — exaggerated but not the same as anaphylaxis. Anaphylaxis affects body systems away from the sting site: throat, airway, blood pressure, GI tract. Large local reactions are confined to the area of the sting, even when severe. Future systemic-reaction risk after a large local reaction is only 5–10% per AAFP. See a clinician within 24 hours for a prednisone course.

How long should itching last after a yellow jacket sting?

Up to 7 days is normal for a local reaction; up to 10 days for a large local reaction (Healthline; Mayo Clinic). Itch typically dominates after the acute pain fades — peaking between days 2 and 5. Topical 1% hydrocortisone cream (applied starting around hour 6) and one oral antihistamine are the most effective interventions.

When does redness from a sting become too much?

Normal redness fades by about day 3 (Cleveland Clinic; Seattle Children's). Redness that is still expanding after 48 hours, is warmer than surrounding skin, or is accompanied by an advancing firm edge suggests cellulitis — a bacterial infection requiring medical treatment. Red streaks running from the sting toward your heart indicate lymphangitis, which is urgent-care level.

Will a yellow jacket sting bruise?

Yes, a yellow-to-purple discoloration in days 3–7 is common and benign — subcutaneous blood that settles near the sting site as swelling decreases. This is part of normal resolution and does not indicate infection or a more serious reaction.

How long does yellow jacket sting pain typically last?

Sharp, burning pain peaks within 10 minutes (Cleveland Clinic; Seattle Children's). The acute pain phase lasts about 10 minutes to 2 hours. A tender, throbbing ache can persist 24–48 hours. By day 2, itch usually replaces pain as the dominant symptom.

Can a sting reaction come back days later?

Biphasic anaphylaxis — a return of systemic symptoms hours after the initial reaction — occurs in about 20% of people who have an anaphylactic reaction (Allergy & Asthma Network). This risk window extends up to 72 hours after the first episode. This is why ER observation after epinephrine use is standard, typically 4–6 hours. If you only had a local reaction with no systemic symptoms, biphasic recurrence is not a concern.

How long should a child's sting reaction last?

The same basic timeline applies — but swelling can look more dramatic on a smaller body. A local reaction should resolve within 3–7 days. If swelling persists past 7 days, if the child develops fever, or if hives appear away from the sting site — contact a pediatrician or the Northern New England Poison Center at 1-800-222-1222 (24/7, NH/ME/VT). Never use adult dosing for children.

How long after a sting can I exercise or return to work?

Most adults can return to normal activity within 24 hours. Avoid heavy exertion with a stung limb during the 24–48 hour swelling peak — physical activity increases blood flow and can worsen edema. After anaphylaxis, follow ER discharge instructions exactly; most providers recommend rest for 24–48 hours after epinephrine use.

How long should I monitor a child after a yellow jacket sting?

Monitor for at least 30 minutes for any systemic signs (trouble breathing, throat tightness, spreading hives, dizziness, vomiting). Allergic children with a known venom allergy should have a written emergency action plan from their pediatrician. The Northern New England Poison Center (1-800-222-1222) is available 24/7 for guidance.

When does an infected sting become a sepsis risk?

Fever above 101°F, chills, rapidly expanding warmth and redness, red streaks, or malaise developing 3–7 days after a sting can indicate spreading infection — go to an NH ER the same day, not urgent care. Staphylococcus aureus and Streptococcus pyogenes are the common culprits and need timely antibiotic treatment. Do not wait and see if this symptom cluster is present.

StingAnchor Pest · New Hampshire

How Long Does a Yellow Jacket Sting Last? Pain, Swelling & Itch Timeline (NH)

TL;DR

A yellow jacket sting hurts sharply for the first few minutes; burning pain eases within 1–2 hours, swelling peaks at 24–48 hours, redness fades by about day 3, and most signs clear within 3–7 days. Large local reactions can take 5–10 days. Anything worsening after 48 hours, or new pus, expanding redness, or fever after a week, may be infection — see a clinician or NH ER. Systemic symptoms within 5–30 min: epinephrine FIRST, then 911. NNEPC: 1-800-222-1222.

Call for a free yellow jacket quote (603) 785-0118

NH License #782664Family-owned since 2017Updated Jun 2026

Pain peaks within
10 minutes
Cleveland Clinic; Seattle Children's
Acute pain phase
10 min – 2 hr
Cleveland Clinic; Healthline
Swelling peaks at
24–48 hr
Mayo Clinic 2024; WebMD; Seattle Children's
Redness fades
~3 days
Seattle Children's; Cleveland Clinic

Overview

Is What You're Seeing After a Sting Normal?

The most common question after a yellow jacket sting isn't about treatment — it's about timing. 'Why is my arm still swollen at day two?' 'Is itching this long normal?' 'Should this still hurt?' Most of these concerns reflect the expected arc of a local reaction, and having the specific timeline prevents unnecessary worry and missed red flags.

For the ~90% of people with a local reaction, the sequence is predictable: sharp pain in the first ten minutes, a swelling peak at 24–48 hours, redness fading around day three, and full resolution within a week. For the ~5–10% with a large local reaction, the same arc plays out over 5–10 days, with the whole-limb swelling often alarming but rarely dangerous.

What breaks that pattern — expanding redness after day two, pus or fever near day five, or any systemic symptom in the first 30 minutes — is the signal to escalate. In southern New Hampshire, NNEPC (1-800-222-1222) and four 24/7 emergency departments across Manchester, Nashua, and Concord are available when that happens.

New Hampshire context

Yellow Jacket Sting Duration in Southern New Hampshire

In southern New Hampshire, yellow jacket activity peaks from mid-August through mid-September — exactly when outdoor work, state park visits, and backyard meals put people in close contact with late-season foragers. The Eastern yellowjacket (Vespula maculifrons, NH's dominant ground nester) and the German yellowjacket (V. germanica, a wall-void specialist) are both most aggressive in this window as colony food sources dwindle before the first frost. Activity collapses with the first hard frost — about October 19 at 50% probability in Manchester per NOAA Manchester-Boston Regional Airport 1991–2020 normals; only mated queens survive to overwinter in stone walls, attic insulation, and woodpiles. Per UNH Cooperative Extension, individual sting recovery timelines are the same regardless of season, but late-summer stings are far more likely to involve multiple stings from an agitated colony.

Species present in NH

Eastern yellowjacket (V. maculifrons)
German yellowjacket (V. germanica)
Bald-faced hornet (D. maculata)
Aerial yellowjacket (D. arenaria)

Peak activity

mid-August through mid-September

Service area

ManchesterNashuaConcordDerryBedfordSalemHooksettGoffstown

First-frost anchor: Manchester first hard frost ~Oct 19 (50%) / Oct 29 (80%) per NOAA Manchester-Boston Regional Airport

Per UNH Cooperative Extension, yellowjacket colonies in NH peak in late summer and collapse with the first hard frost; only mated queens overwinter.

Symptom tiers

Three reactions — local, large local, anaphylaxis

Three buckets cover essentially every yellowjacket sting. The big jump in risk happens between tier 2 and tier 3.

Tier 1

Local Reaction

Tier 2

5–10% of stings

Large Local Reaction

Tier 3

Systemic Reaction (Anaphylaxis)

Tier 1

Local Reaction

Who gets it

~90% of stings

What to expect

Pain, redness, swelling, warmth, and itch confined to the sting site — under 4 inches across. Resolves in 3–7 days; itching can persist up to a week (Cleveland Clinic; Mayo Clinic).

What to do

Ice, one oral antihistamine, ibuprofen for pain, 1% hydrocortisone cream from hour 6. No ER needed unless systemic signs develop.

Tier 2

Large Local Reaction

Who gets it

~5–10% of stings

What to expect

Swelling over 4 inches across or involving an entire limb. Peaks at 48–72 hours and resolves over 5–10 days. May include low-grade fever, fatigue, mild nausea. NOT a sign of dangerous systemic allergy. Future systemic-reaction risk only 5–10% (AAFP).

What to do

See a clinician within 24 hours. A short prednisone course may be prescribed. Continue oral antihistamine. Watch for systemic symptoms.

Tier 3

Systemic Reaction (Anaphylaxis)

Who gets it

<1% of stings (~3% of adults lifetime per ACAAI)

What to expect

Symptoms away from the sting site within 5–30 minutes: wheezing, throat tightness, spreading hives, weak pulse, dizziness, vomiting, or sense of doom. Onset is rapid. Biphasic return possible in about 20% of cases (Allergy & Asthma Network).

What to do

Epinephrine FIRST (auto-injector to outer thigh), then 911. Lay flat unless vomiting. Go to ER even if symptoms resolve — biphasic risk window extends up to 72 hours.

Time-critical

Schmidt sting pain index

How bad does a yellowjacket sting really hurt?

Justin Schmidt rated the yellow jacket sting at 2.0 on his 1–4 index — 'hot and smoky, almost irreverent.' Peak pain occurs within 10 minutes; understanding the full arc prevents unnecessary alarm at the 24-hour swelling peak.

Sweat bee
1.0
Light and ephemeral, almost fruity
Fire ant
1.2
Sharp, sudden, mildly alarming
Bald-faced hornet
2.0
Rich, hearty, slightly crunchy
Yellow jacketYellowjacket
2.0
Hot and smoky, almost irreverent
Honey bee
2.0
Like a matchhead pressed into the skin
Paper wasp
3.0
Caustic and burning, with a distinctly bitter aftertaste
Bullet ant
4.0
Pure, intense, brilliant pain — like walking over flaming charcoal

Recovery timeline

What happens hour-by-hour after a sting

0–10 min
Sharp, burning pain peaks at the sting site. Venom components including phospholipase A₂, hyaluronidase, antigen 5, and kinins trigger immediate inflammation. Schmidt index 2.0 — 'hot and smoky.'
Action: Move 30+ ft from the nest immediately. Alarm pheromone recruits additional defenders within seconds (UMd Bug of the Week; Penn State Extension).
Moderate
10 min – 2 hr
Acute inflammatory phase. Histamine and bradykinin release causes a wheal-and-flare response, throbbing pain, and spreading localized redness. This is the window when anaphylaxis almost always begins if it is going to occur.
Action: Wash 60 seconds. Ice 10 on/10 off. Take one oral antihistamine + ibuprofen (adults). Monitor closely for systemic signs — onset window 5–30 min (ACAAI; Cleveland Clinic).
Moderate
2–24 hr
Pain declines as the late-phase response shifts from kinins to histamine-dominated pruritus. Itch begins to replace acute pain. Warmth and redness persist.
Action: Apply 1% hydrocortisone cream starting around hour 6 when itch dominates.
Mild
24–48 hr
Swelling reaches maximum extent. Normal local reaction stays under 4 inches across. Large local reaction (5–10% of stings) can involve an entire limb or cross a major joint — still not anaphylaxis (AAFP).
Action: For large local (>4 in): see a clinician within 24 hours. For normal local: continue home care. Any new systemic symptoms at this stage are unexpected — call NNEPC 1-800-222-1222 for guidance.
Mild
48 hr – Day 3
Redness begins fading. Swelling starts to recede in normal local reactions. Itching typically peaks during this window as the inflammatory mediators shift.
Mild
Day 3 – Day 7
Most normal local reactions fully resolve. Mild residual bruising or discoloration (yellow-purple) is common and benign. Itching is usually the last symptom to clear.
Mild
Day 5 – Day 10
Large local reactions reach full resolution. Whole-limb swelling subsides. Future systemic-reaction risk from this type of reaction is only 5–10% per AAFP — a large local reaction alone is not grounds for automatic venom immunotherapy consideration.
Mild
Day 7+
Persistent or worsening redness, warmth, fever, pus, or expanding red streaks (lymphangitis) at this stage indicate secondary bacterial infection, typically Staphylococcus aureus or Streptococcus pyogenes. This is not a sting reaction — it is a wound infection.
Action: Medical evaluation same day — likely oral antibiotics. Go to an NH ER or urgent care; do not wait.
Severe

First-aid protocol · step-by-step

Eight steps — the home protocol that actually works

01
Move 30+ feet from the nest immediately
Alarm pheromone triggers nestmate recruitment within seconds. Distance is the first treatment.
Do not swat at yellowjackets — that increases sting count.
02
Wash with soap and cool water for 60 seconds
Reduces surface contamination and secondary infection risk.
soapcool water
03
Ice through cloth — 10 min on, 10 off — first hour
Reduces local pain and swelling. Elevate the stung limb if possible.
ice packcloth wrap
04
Take one oral antihistamine (adults)
Diphenhydramine 25–50 mg OR cetirizine 10 mg OR loratadine 10 mg — choose one. Do not stack.
For children: consult pediatrician or NNEPC 1-800-222-1222. Never use adult doses.
05
Add ibuprofen 400 mg with food for pain (adults)
Reduces pain and inflammation. No aspirin for anyone under 18 — Reye's syndrome risk (CDC; Mayo Clinic).
For children: consult pediatrician or NNEPC 1-800-222-1222.
06
Apply 1% hydrocortisone cream starting around hour 6
Once itch dominates, topical hydrocortisone cream up to 3 times daily eases pruritus.
1% hydrocortisone cream
07
Monitor 30 min for systemic signs
Anaphylaxis onset window is 5–30 min. Watch for hives away from the sting, throat tightness, dizziness, vomiting.
08
If systemic signs: epinephrine FIRST, 911 SECOND
Use epinephrine auto-injector (EpiPen / Auvi-Q / generic equivalent) into outer thigh, then call 911. Lay flat unless vomiting. Go to ER even if symptoms resolve — biphasic risk.
Do not drive yourself — syncope risk. Antihistamines are NOT a substitute for epinephrine (ACAAI).

Emergency · do not miss

Red flags — call 911 immediately

Emergency · red flags

These signs indicate the sting is not following a normal recovery track. Any anaphylaxis signs require epinephrine first, then 911.

Warning signs

Swelling still expanding past 48 hours
Redness with an advancing warm edge after day 2 — suggests cellulitis
Red streaks running from the sting toward the heart — lymphangitis, urgent care
Fever above 100.4°F / 38°C
Pus, abscess, or skin breakdown
Pain worsening rather than improving after day 3
Any systemic symptoms (wheezing, spreading hives, dizziness, vomiting) within 5–30 min — anaphylaxis

Call 911 when

Systemic anaphylaxis signs: trouble breathing, throat tightness, spreading hives, dizziness, fainting
Sting to the mouth or throat — airway risk regardless of allergy
Known venom allergy — epinephrine first, then 911

3 ERs · 1 Poison Center · 24/7

New Hampshire emergency contacts

For anaphylaxis, call 911. For dosage or poisoning questions, call NNEPC 1-800-222-1222. NH 24/7 emergency departments closest to Anchor's service area:

Poison center · NH, ME, VT

Northern New England Poison Center

24/7 · Text POISON to 85511

1-800-222-1222

Manchester, NH

Catholic Medical Center

100 McGregor St, Manchester, NH 03102

Level IIIER 24/7

(603) 668-3545

Manchester, NH

Elliot Hospital

1 Elliot Way, Manchester, NH 03103

Level IIER 24/7Pediatric ER

(603) 669-5300

Only dedicated Pediatric ED in the core service area

Nashua, NH

Southern New Hampshire Medical Center

8 Prospect St, Nashua, NH 03060

Level IIIER 24/7

(603) 577-2000

Pet sting

What to do if your dog or cat is stung

Dogs are often stung in the face or mouth when snapping at flying yellow jackets. Normal pet sting swelling peaks within 1–4 hours and resolves within 24–48 hours. Watch the first 30–60 minutes closely for facial or neck swelling, hives under fur, labored breathing, vomiting, weakness, or pale gums — those signs require immediate emergency vet care. NEVER give pets human ibuprofen, naproxen, or aspirin — all are toxic.

Airway-risk signs

Facial or muzzle swelling within 30 minutes of the sting
Labored breathing, wheezing, or unusual respiratory sounds
Hives visible under the fur
Vomiting or sudden weakness

NH emergency vets

Veterinary Emergency Center of Manchester
Manchester
(603) 666-6677
Port City Veterinary Referral Hospital
Portsmouth
(603) 433-0056

Common questions

Frequently asked

Anchor Pest Services

Yellowjackets gone — and they stay gone.

Same-day service across Southern New Hampshire. NH-licensed #782664. Family-owned since 2017. We handle ground, wall, and aerial nests with EPA-registered products and a 30-day re-treat guarantee.

Call for a Free Quote Call (603) 785-0118

NH License #782664Manchester, NH 03103Monday-Friday 8am-5pm

How Long Does a Yellow Jacket Sting Last? Pain, Swelling & Itch Timeline (NH)

Is What You're Seeing After a Sting Normal?

Yellow Jacket Sting Duration in Southern New Hampshire

Three reactions — local, large local, anaphylaxis

Local Reaction

Large Local Reaction

Systemic Reaction (Anaphylaxis)

How bad does a yellowjacket sting really hurt?

What happens hour-by-hour after a sting

Eight steps — the home protocol that actually works

Move 30+ feet from the nest immediately

Wash with soap and cool water for 60 seconds

Ice through cloth — 10 min on, 10 off — first hour

Take one oral antihistamine (adults)

Add ibuprofen 400 mg with food for pain (adults)

Apply 1% hydrocortisone cream starting around hour 6

Monitor 30 min for systemic signs

If systemic signs: epinephrine FIRST, 911 SECOND

Red flags — call 911 immediately

New Hampshire emergency contacts

Northern New England Poison Center

Catholic Medical Center

Elliot Hospital

Southern New Hampshire Medical Center

What to do if your dog or cat is stung

Frequently asked

Why is my yellow jacket sting still swelling at 36 hours?

My whole arm or leg is swollen from a sting — is that anaphylaxis?

How long should itching last after a yellow jacket sting?

When does redness from a sting become too much?

Will a yellow jacket sting bruise?

How long does yellow jacket sting pain typically last?

Can a sting reaction come back days later?

How long are yellow jackets active in New Hampshire?

How long should a child's sting reaction last?

How long after a sting can I exercise or return to work?

How long should I monitor a child after a yellow jacket sting?

When does an infected sting become a sepsis risk?

Sources & further reading (12)

Yellowjackets gone — and they stay gone.

How Long Does a Yellow Jacket Sting Last? Pain, Swelling & Itch Timeline (NH)

Is What You're Seeing After a Sting Normal?

Yellow Jacket Sting Duration in Southern New Hampshire

Three reactions — local, large local, anaphylaxis

Local Reaction

Large Local Reaction

Systemic Reaction (Anaphylaxis)

How bad does a yellowjacket sting really hurt?

What happens hour-by-hour after a sting

Eight steps — the home protocol that actually works

Move 30+ feet from the nest immediately

Wash with soap and cool water for 60 seconds

Ice through cloth — 10 min on, 10 off — first hour

Take one oral antihistamine (adults)

Add ibuprofen 400 mg with food for pain (adults)

Apply 1% hydrocortisone cream starting around hour 6

Monitor 30 min for systemic signs

If systemic signs: epinephrine FIRST, 911 SECOND

Red flags — call 911 immediately

New Hampshire emergency contacts

Northern New England Poison Center

Catholic Medical Center

Elliot Hospital

Southern New Hampshire Medical Center

What to do if your dog or cat is stung

Frequently asked

Why is my yellow jacket sting still swelling at 36 hours?

My whole arm or leg is swollen from a sting — is that anaphylaxis?

How long should itching last after a yellow jacket sting?

When does redness from a sting become too much?

Will a yellow jacket sting bruise?

How long does yellow jacket sting pain typically last?

Can a sting reaction come back days later?

How long are yellow jackets active in New Hampshire?

How long should a child's sting reaction last?

How long after a sting can I exercise or return to work?

How long should I monitor a child after a yellow jacket sting?

When does an infected sting become a sepsis risk?

Sources & further reading (12)

Related yellowjacket pages

Yellowjackets gone — and they stay gone.