What is a mosquito bite?
A mosquito bump is a strongly itchy reaction that develops at the spot where a mosquito sucks blood. Mosquitoes occur in large numbers in summer, especially in areas with a lot of water. For reproduction the mosquito needs water to lay its eggs and blood to produce them.
Which mosquito is to blame?
Mosquitoes occur worldwide. Well known, of course, are the malaria mosquitoes that transmit the malaria parasite in (sub)tropical areas. The common biting mosquito (family Culicidae) causes a lot of nuisance in summer and early autumn. Most species are not biting; of the biting mosquitoes, only the female sucks blood and so causes the nuisance.
What does a mosquito bite look like?
The common mosquito bite causes an intensely itchy bump at the site of the bite, strongly resembling that of urticaria (hives). The swelling usually largely disappears within a few hours, but the itch often persists longer, and scratching can repeatedly “reactivate” the swelling. Sometimes the skin reaction is so strong that a blister develops at the bite; this hypersensitivity reaction is called “culicosis” (or “culicosis bullosa”). The bumps and blisters dry up after a number of days. Sometimes a bacterium enters the spot and a bacterial infection develops. Culicosis is seen mainly in children.
How are they treated?
Itch from insect bites can be treated with pramocaine cream, available without prescription. Strongly itching bites can be treated with a corticosteroid ointment, which is often very effective against itch and need not be used for more than a few days; topical antihistamines can also help against the itch and swelling. If a bacterial infection complicates the bite, treatment with an antibiotic ointment (for example fusidic acid) is recommended; for a more extensive bacterial infection it is advisable to consult a doctor, as a systemic antibiotic may then be needed.
How do I prevent mosquito bites?
- Barrier — prevent mosquitoes entering the house with screens on windows and doors.
- Swatting — mosquitoes that do get in are usually not hard to catch, as they are relatively slow insects.
- Clothing — outdoors in mosquito-rich areas, wear long sleeves, for example.
- Scents — mosquitoes seem not to like the smell of lemon; lemon-scented products exist, but their value is doubtful and any effect is short-lived at best.
- DEET — products containing DEET (N,N-diethyl-m-toluamide) are very effective at keeping mosquitoes away. DEET is applied to the skin and works, depending on the concentration, for about 3–8 hours. It does have limitations: it can cause health problems if swallowed, and caution is usually advised when using it on young children and pregnant women.
When to see a doctor
See a doctor if a bite becomes increasingly red, warm, swollen or painful (signs of a bacterial infection), or if you have a severe allergic reaction.