Scabies vs bed bug bites
Scabies is not a bite — it is an infestation of the skin itself, and it appears symmetrically in finger webs, wrists, waistline and groin, with itch that is worst at night. Bed bug welts land on skin left uncovered by bedding, in lines. Scabies needs a prescription; bed bugs need pest control.
Side by side
| Scabies rash | Bed bug bite | |
|---|---|---|
| Looks like | tiny red bumps with thin grey-white burrow lines a few millimetres long | firm, flat-topped welts, often with a darker centre |
| Pattern | symmetrical, in finger webs, wrists, waistline, armpits and groin | lines or zigzags of three or more — the classic "breakfast, lunch and dinner" |
| Size | 1–10 mm | 2–15 mm |
| Appears | 2 to 6 weeks after first exposure; within days on re-exposure | hours to several days — many people notice nothing on the first night |
| Lasts | until treated — it does not resolve on its own | 1 to 2 weeks |
| Itch | ●●●●● 5/5 | ●●●●● 5/5 |
| Pain | ●○○○○ 1/5 | ●○○○○ 1/5 |
| Usually on | finger webs, wrists, elbows, waistline, armpits, groin | arms, shoulders, neck, face, hands — skin left uncovered by bedding |
| Active | itch is classically far worse at night | the small hours, roughly 2am to 5am |
| Where from | transmitted by prolonged skin-to-skin contact — households, care homes, sexual contact; not from pets | mattress seams, bed frames, headboards, sofa joints, luggage; they hide within a few metres of where you sleep |
| Disease risk | secondary bacterial skin infection is common from scratching | none known in the US |
What actually settles it
Symmetry and location. Scabies goes for warm skin folds on both sides of the body. Bed bugs go for arms, shoulders, neck and face — whatever the duvet leaves out.
Burrows. Short grey-white lines a few millimetres long between the fingers are the specific finding for scabies when visible.
Who else itches. Scabies spreads by prolonged skin contact, so households and partners itch together. Bed bug reactions vary so much between people that an unbitten partner proves nothing.
Timing. Scabies itch starts weeks after first exposure and never resolves on its own. Bed bug bites resolve in one to two weeks — and come back the next night.
Treatment differs completely. Scabies: permethrin cream or oral ivermectin for every household member at once. Bed bugs: treat the room, not the skin.
When either one needs a doctor
- itch that keeps the whole household awake
- crusted, thickened skin — a severe form that is highly contagious
- weeping, crusting or fever from scratched skin
- blisters over a wide area
- signs of skin infection — spreading warmth, pus, fever
- in rare cases, breathing difficulty or widespread hives (allergic reaction)
Questions
Can you have both at once?
Yes, and it happens more often than people expect — which is why the pattern of the bites matters more than any single mark.
Which one is more serious?
Scabies rash carries the wider disease risk in the US. For both, the common complication is infection from scratching.
What if I still cannot tell?
Photograph the bites over several days and note where on your body they appear and when. Progression and position identify a bite far more reliably than a single photograph.
Get a photo assessment in the app
Everything above is free to read. The app adds what a page cannot: point your camera at the bite and get an assessment of the most likely cause, a severity read, and a day-by-day care plan — including the specific signs that mean you should be seen.
iPhone and iPad. Free to download.