Midge bite allergy
Reactions to midge (gnat) bites.
About midge bite allergy
Biting midges are tiny flies, often barely visible, whose females feed on blood and are especially troublesome in still, humid conditions, near water and at dawn and dusk. The itchy spots they leave are a reaction to proteins in their saliva. People vary greatly in how strongly they react, and repeated exposure can increase sensitivity. Midges can bite in large numbers, so multiple bites are common, particularly in areas such as parts of Scotland during the summer months.
Reactions usually appear within minutes and typically show as small, red, intensely itchy bumps, sometimes with tiny blisters, and often grouped where the insects have fed on exposed skin. Scratching can break the skin and lead to secondary infection. Most reactions are local and settle over several days, though some people develop larger, more persistent swellings. Whole-body allergic reactions to midge bites are uncommon.
Management focuses on relieving the itch and protecting the skin. A pharmacist can suggest treatments to ease itching, and keeping the area clean and avoiding scratching help prevent infection. A GP can advise if a bite becomes infected, shows spreading redness or swelling, or reactions are severe. Prevention is often the most practical approach: using insect repellent, covering exposed skin, and avoiding midge-prone places at peak times such as dawn and dusk. A rare severe reaction with breathing difficulty or collapse is a medical emergency requiring 999.
Common triggers
- Midge 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.