Insect Bite Treatment in Phuket: Infected Bites, Stings and Allergic Reactions
Clinically reviewed by Dr. Ponlawat Pitsuwan, Physician, Takecare Clinic Phuket. Last reviewed: September 2026.
“The bites that bring people to us are rarely the fresh ones. It is usually a cluster of sandfly or mosquito bites around the ankles that were scratched in the night, then walked through sand and sea water for three days, and have now turned into red, swollen, weeping patches. In this heat and humidity a scratched bite can become infected surprisingly quickly. The other group we take seriously is anyone who develops a fever in the two weeks after being bitten, because mosquito-borne infections such as dengue are part of life in Phuket.” Dr. Ponlawat Pitsuwan
What bites and stings in Phuket
An insect bite is an allergic and inflammatory reaction to the saliva an insect injects while feeding; a sting injects venom for defence. The size of the reaction depends more on your immune system than on the insect. First-time visitors often react more strongly because their skin has not met the local species before.
Mosquitoes
Mosquitoes are the most common biters and the most important for health. The Aedes mosquito bites mainly during the day, especially in the early morning and late afternoon, and can spread dengue, chikungunya and Zika virus. Dengue is present in Phuket year round, with more cases in the rainy season. Night-biting Culex mosquitoes can carry Japanese encephalitis, a viral brain infection that is rare in travellers and mostly linked to rural rice-farming areas.
Sandflies and biting midges
What people in Phuket call sandflies are tiny biting insects found on some beaches, especially around dawn and dusk and near damp sand or mangroves. You rarely see them. Their bites are small, intensely itchy red bumps, usually on the ankles, legs and anywhere exposed while sitting on the sand, and the itch can last a week. They are the classic bite that gets scratched open and infected.
Fire ants, bed bugs, centipedes and scorpions
Fire ants sting when their nest is disturbed, often in garden lawns or at the edge of the sand. The sting burns immediately, and within about a day a small white pus-filled spot (a sterile pustule) forms at each sting; it is not an infection and should not be popped. Bed bugs hide in mattresses and furniture and bite exposed skin at night, often leaving itchy bites in a line or cluster that you notice in the morning.
Centipedes are common in Phuket gardens, villas and bathrooms, especially in the rainy season. Large ones deliver a very painful bite with two small puncture marks, redness and swelling that can spread up the limb. They are rarely dangerous to healthy adults but are frightening and can cause nausea or a racing heart from pain. Scorpion stings in Thailand are usually painful and local rather than life-threatening in adults, but children should always be checked. Bees, wasps and hornets matter mainly because of allergy: a single sting can trigger anaphylaxis in a sensitised person.
Normal bite, infected bite or allergic reaction?
A normal bite is an itchy raised bump that may swell for a day or two. A large local reaction is a bigger area of swelling, sometimes 10 centimetres or more across or involving a whole hand or ankle, that peaks at 24 to 48 hours; it looks alarming but is an allergic response, not an infection, and it is usually itchy rather than increasingly painful. An infected bite gets worse after the first day or two: more pain, spreading redness, warmth, pus or a yellow crust. When infection spreads into the deeper skin it is called cellulitis, and red streaks tracking up the limb (lymphangitis) or a fever mean it is spreading further.
| What you see | Likely cause | What to do |
|---|---|---|
| Itchy bumps on ankles after the beach | Sandfly or mosquito bites | Cold compress, antihistamine, hydrocortisone cream, do not scratch |
| Big itchy swelling peaking at 1 to 2 days | Large local allergic reaction | Antihistamine, elevate the limb; doctor if very large or near the eye |
| Increasing pain, heat, pus or red streaks after day 2 | Infected bite or cellulitis | See a doctor today for antibiotics |
| Severe pain, two puncture marks | Centipede bite | Wash, warm water soak, pain relief, tetanus check |
| Swollen lips or tongue, wheeze, hives, faintness | Anaphylaxis | Use adrenaline auto-injector if you have one, call 1669 |
| Fever, headache, body aches within 2 weeks of bites | Possible dengue or other mosquito-borne infection | Blood test; paracetamol only, avoid ibuprofen and aspirin |
How we treat insect bites at Takecare
The doctor looks at the bites, asks what you think bit you and when, and checks for spreading redness, swollen lymph glands and fever. We often draw around the edge of any redness with a skin pen so that you and we can see whether it is spreading or shrinking over the next day.
For itchy and allergic bites, treatment is a non-drowsy oral antihistamine such as cetirizine or loratadine, a topical corticosteroid cream to calm the inflammation, and cold compresses. A large local reaction may need a short course of oral prednisolone, a steroid tablet. Infected bites are cleaned and treated with an antibiotic that covers the usual skin bacteria, Staphylococcus aureus and Streptococcus, such as flucloxacillin or cefalexin, with alternatives for people allergic to penicillin. Mild, localised crusting can sometimes be managed with an antiseptic or antibiotic cream alone.
Centipede and scorpion stings are treated with strong pain relief, sometimes a local anaesthetic injection around the bite, and soaking in warm water, which many patients find eases the pain. We check tetanus status for any bite or sting that has broken the skin. If you have had a fever since your bites, we can test for dengue in our laboratory with an NS1 antigen test and a full blood count on the same visit.
When to see a doctor
See a doctor the same day if a bite is becoming more painful, red, hot or swollen after the first 48 hours, if you see pus, a spreading yellow crust or red streaks, or if you have a fever, chills or swollen glands in the groin or armpit. Bites near the eye that swell the eyelid shut, many bites on a small child, a centipede or scorpion sting in a child, and any bite in someone with diabetes or a weakened immune system also need review. A fever, headache, eye pain, joint pain or a rash within two weeks of mosquito bites needs a blood test.
Call 1669 or go to a hospital emergency department immediately if someone has swelling of the lips, tongue or throat, difficulty breathing or swallowing, wheeze, widespread hives with dizziness, or collapses after a sting. Use an adrenaline auto-injector straight away if they carry one, and lie them flat with legs raised unless breathing is easier sitting up.
Prevention and early detection
Use an effective insect repellent on exposed skin, especially from early morning to late afternoon when the dengue mosquito is active, and again at dusk for sandflies. The best-studied active ingredients are DEET (20 to 50%) and picaridin, also called icaridin (about 20%); IR3535 and oil of lemon eucalyptus are alternatives. Apply sunscreen first and repellent on top, and reapply after swimming or heavy sweating. DEET can be used on children older than two months at appropriate strengths, following the label. Light-coloured long sleeves and trousers at dawn and dusk, clothing treated with permethrin, air conditioning or a fan at night, and a mosquito net where rooms are not screened all reduce bites.
At the beach, sit on a chair or mat rather than directly on damp sand at dusk. In villas, shake out shoes and towels before use and check bedding for centipedes. Early detection means looking at your bites each day for the first few days: a bite that is more painful on day three than on day one is heading the wrong way.
Visiting Takecare Clinic in Phuket
We are open 24 hours a day, every day, at three branches, and you can walk in without booking. Visit Takecare Clinic Bangtao (Cherngtalay) on Bandon Road for the north-west coast, Takecare Clinic Kata-Karon for Kata and Karon, or Takecare Clinic Patong in the centre of Patong. Most visits take under 30 minutes, and antihistamines, creams and antibiotics are dispensed on site.
If a child has been stung in the night, or a swollen leg makes walking difficult, a doctor can visit your hotel or villa anywhere in Phuket around the clock. Send us a photo of the bite on WhatsApp or call 081-718-9080 for advice.
We confirm the price on WhatsApp before your visit, offer direct billing with most travel insurers, and supply a medical report and itemised receipt for insurance claims.
Related services and treatments
Anyone who has had a severe reaction to a sting before should discuss allergy treatment and emergency medication with a doctor while they are here. Bites that have already turned into spreading redness are covered in more detail on our skin infection treatment page. Intensely itchy spots between the fingers, on the wrists or around the waist that are worse at night are sometimes mistaken for bites but are actually scabies, explained on our scabies treatment in Phuket page.
Other beach-related skin problems are common too. A painful welt after swimming may need jellyfish sting care, reddened peeling skin may need sunburn treatment, and a burning, blistering band on one side of the body that is not a bite at all may need shingles treatment. You can also book a doctor hotel visit in Phuket or see a walk-in doctor in Phuket for any other concern.
Summary
Insect bites in Phuket come mainly from mosquitoes, sandflies, fire ants and bed bugs, with centipedes and scorpions causing painful but usually not dangerous stings. Most bites settle with antihistamines, steroid cream and not scratching. Bites that grow more painful, red and hot after two days are infected and need antibiotics, and a fever after mosquito bites needs a dengue test. Swelling of the face or throat or difficulty breathing after a sting is anaphylaxis and needs 1669. Takecare Clinic Phuket treats bites around the clock in Bangtao, Kata and Patong, or at your hotel.
“Repellent in the morning, repellent again at sunset, and an antihistamine at bedtime so you do not scratch in your sleep. That routine prevents most of the infected bites and much of the dengue risk we deal with.” Dr. Ponlawat Pitsuwan
Frequently asked questions
How do I know if an insect bite is infected?
An infected bite gets worse after the first 48 hours instead of better. Look for increasing pain, spreading redness, warmth, swelling, pus or a golden crust, red streaks running up the limb, swollen glands, or a fever. A large itchy swelling that appears on the first day is usually an allergic reaction, not infection. If you are unsure, send us a photo on WhatsApp or come in.
What are the itchy bites on my ankles after the beach?
Small, intensely itchy red bumps on the ankles and lower legs after sitting on the sand around dawn or dusk are very often sandfly bites. They can itch for a week and are easily scratched open. An oral antihistamine, a hydrocortisone cream and a cold compress help. Keep them covered in the sea and see a doctor if they become painful, hot or weepy.
Do I need an appointment for insect bite treatment?
No. All three Takecare branches in Bangtao, Kata and Patong welcome walk-ins 24 hours a day, and you are usually seen within minutes by an English-speaking doctor. Treatment, including antibiotics or antihistamines, is dispensed from our pharmacy before you leave. You can message us on WhatsApp first if you would like advice on whether to come in.
Can a doctor come to my hotel for a bite or sting?
Yes. Our doctors visit hotels and villas across Phuket day and night. This is especially useful for a child stung by a centipede at night, a very swollen leg, or anyone with a fever who feels too unwell to travel. The doctor can examine the bite, give pain relief, start antibiotics and arrange a blood test if needed.
Which insect repellent works best in Phuket?
Repellents containing DEET at 20 to 50% or picaridin at about 20% are the most effective against mosquitoes and sandflies, and both are widely available in Phuket pharmacies and convenience stores. Apply them after sunscreen, reapply after swimming or sweating, and use them during the day as well as at night, because the dengue mosquito bites mostly in daylight hours.
Will travel insurance pay for insect bite treatment?
Most travel insurance policies cover treatment for infected bites, allergic reactions and stings that happen during your trip. We offer direct billing with most travel insurers, and if you need to pay and claim later we provide a medical report and itemised receipt. Tell us your insurer’s name on WhatsApp and we will confirm the arrangements before you visit.
Sources
NHS: Insect bites and stings. WHO: Dengue and severe dengue. CDC: Preventing mosquito bites.
Insect bites, insect stings, mosquito bites, Aedes, Culex, dengue, chikungunya, Zika virus, Japanese encephalitis, sandflies, biting midges, fire ants, bed bugs, centipede bite, scorpion sting, large local reaction, infected bite, cellulitis, lymphangitis, anaphylaxis, adrenaline auto-injector, cetirizine, loratadine, hydrocortisone, prednisolone, flucloxacillin, cefalexin, NS1 antigen test, DEET, picaridin, icaridin, IR3535, permethrin, tetanus, NHS, WHO, CDC, 1669, Bangtao, Cherngtalay, Kata, Karon, Patong, Phuket, Dr. Ponlawat Pitsuwan, Takecare Clinic Phuket.
This page is general health information and not a substitute for a medical consultation.