That could point to a few different skin conditions, but the pattern you mention—“lines of red bumps all over”—is important because some causes follow a linear or grouped pattern.
Common possibilities
1) Insect bites (very common)
- Bedbugs or fleas often cause lines or clusters of red, itchy bumps
- Often appear overnight
- Usually on arms, legs, back, or areas exposed during sleep
2) Scabies
- Tiny mites that cause very itchy bumps in lines or tracks
- Itching is usually worse at night
- Common areas: between fingers, wrists, waist, groin
3) Allergic reaction / hives
- Can form raised red streaks or patches
- Often itchy and may move or change shape
- Triggered by food, medicine, soap, or detergent
4) Contact dermatitis
- Reaction to something touching the skin (new clothing, plants, chemicals)
- Can appear where contact occurred, sometimes in streak-like patterns
🚨 When to seek medical help quickly
- Severe itching that’s getting worse
- Spreading rash over hours/days
- Fever, swelling, or feeling unwell
- Signs of infection (pus, warmth, pain)
What you can do now
- Avoid scratching
- Check bedding/mattress for insects
- Wash clothes and bedsheets in hot water
- Use a mild antihistamine if itching is severe (if safe for him)
If you can, tell me:
- Is it itchy or painful?
- Where on his body is it?
- Did it appear suddenly (like overnight)?
That will help narrow it down a lot.
