Bedbug bite allergy
Itchy welts from bedbug bites.
About bedbug bite allergy
Bedbugs are small, wingless insects that feed on blood, usually at night, and hide in mattresses, bed frames and furniture. The itchy welts that follow a bite are largely a reaction to proteins in the insect's saliva, injected while it feeds. Not everyone reacts, and sensitivity varies from person to person; some people notice little or nothing, while others develop marked itchy spots. Bites often appear in rows or clusters on skin exposed during sleep, such as the arms, neck and legs.
Reactions usually appear within minutes to a day or so of being bitten and typically show as small, red, itchy raised bumps, sometimes with a firm swelling. Scratching can break the skin and lead to secondary infection. Bedbug bites are not known to spread disease, and reactions are generally local rather than a whole-body allergic response, though occasional people react more strongly. Bites usually settle over one to a few weeks.
Management focuses on relieving the itch and treating the infestation, since bites will keep occurring until the bedbugs are eradicated. Keeping the skin clean, avoiding scratching and using measures recommended by a pharmacist can help, and a GP can advise if a bite becomes infected or reactions are severe. Eliminating an infestation often needs thorough cleaning, laundering at high temperatures and professional pest control. If a bite shows spreading redness, swelling or pus, medical advice should be sought.
Common triggers
- Bedbug bite and products containing it
Symptoms
- Pain, redness and swelling at the sting or bite
- Widespread hives or itching
- Swelling of the face, lips or throat
- Wheezing or difficulty breathing
- Anaphylaxis in severe cases
Avoidance & management
- Avoid nests, hives and known habitats
- Wear covering clothing and avoid strong scents outdoors
- Use insect repellent and screens
- Carry an adrenaline auto-injector if prescribed
- Seek urgent help for a severe reaction
Sources & references
Allergy safety: what everyone should know
Mild-to-moderate reaction signs
- Itching, hives or a raised rash
- Swelling of lips, face or eyes
- Tingling mouth, sneezing, runny nose
- Stomach pain, nausea or vomiting
Anaphylaxis — call 999 (UK) or 112 (EU) immediately
- Difficult or noisy breathing, wheeze, persistent cough
- Swelling of the tongue or tightness in the throat
- Dizziness, collapse, pale and floppy (young children)
- Use an adrenaline auto-injector (e.g. EpiPen) at once if prescribed, then call an ambulance even if symptoms improve
Allergy or intolerance? A true allergy involves the immune system and can escalate quickly; an intolerance (e.g. lactose intolerance) is unpleasant but not life-threatening. The symptoms overlap, so self-diagnosis is unreliable.
Getting tested: home-testing kits based on IgG are not diagnostically valid. If you suspect an allergy, ask a GP for referral to an allergy clinic for skin-prick or specific-IgE testing and a supervised food challenge where appropriate.