How long do bug bites last?

When did the reaction actually start?

A bite and its visible mark do not necessarily arrive together. A mosquito bite can produce a puffy bump within minutes, or a harder itchy bump a day or so later. Bed bug marks can take one to a couple of days to appear. A mark noticed today does not necessarily mean you were bitten today.23

Mosquito saliva triggers the bump and itching. Some people have a mild reaction; others develop a larger area of swelling, redness and soreness. Children, people with immune system disorders and adults encountering an unfamiliar mosquito species can have stronger reactions.3

The term bug bite includes encounters with insects, spiders and ticks, so even the category has paperwork problems. Mosquito, flea and mite bites tend to itch, while bee, wasp and hornet stings and fire ant bites are more often painful.145

What can you do while the bite settles?

1. 1Wash the bite and surrounding skin gently with soap and water.
2. 2Wrap an ice pack in a thin towel. Apply it for 10 minutes to ease swelling and itching, then leave it off for 10 minutes before repeating.
3. 3Use an itch relieving cream, such as hydrocortisone, following the product label. An oral antihistamine is another option for reducing itch.
4. 4Avoid scratching. Scratching can break the skin and allow infection to develop.
5. 5Watch the area over the next several days for increasing redness, swelling or pain.

For bed bug bites, hydrocortisone 1% cream or lotion can relieve itching. If itching is severe enough to cause extreme discomfort, a healthcare provider can consider a stronger steroid cream or an antihistamine.2

Are old bites lingering, or are new bites appearing?

Bed bugs usually feed every three to seven days, so an ongoing infestation can mean repeated bites rather than one bite that never heals. Bite appearance alone is not enough to confirm bed bugs because their marks resemble other insect bites. Look for live bugs, shed skins or rust colored stains around bedding and mattress seams.2

Bed bugs can enter a spotless home on luggage or used furniture, so a clean house is not a border control system. Treating the skin does not remove an infestation. Contact a pest control professional, or your landlord if you rent; eliminating bed bugs can take weeks to months.2

When should you stop waiting and get help?

Get medical care if symptoms worsen, especially if the bite feels warm, redness spreads outward in a streak, or swelling and pain increase. Those changes can indicate infection. The direction of the symptoms matters more than simply counting days.34

Call your local emergency number for trouble breathing, throat tightness, difficulty swallowing, swelling of the face or mouth, or fainting. These can signal anaphylaxis, a severe allergic reaction. If you have a prescribed epinephrine injector, use it as directed and seek emergency care.14

Seek prompt medical care for fever, body aches, persistent tiredness or a new rash after a bite. A ring shaped rash after a tick bite or fever with a spreading red or black spotty rash needs immediate assessment. After travel, tell the clinician where you went: dengue symptoms usually start within two weeks of an infected mosquito bite and can include fever, aches, nausea and rash.67

How can you avoid more bites?

Use an EPA registered insect repellent and wear loose fitting long sleeves and long pants to prevent mosquito bites. Be careful around outdoor food and drinks, which attract insects. If you have a known severe insect allergy, carry your prescribed emergency epinephrine kit.345