Clinically reviewed by Dr. Ponlawat Pitsuwan, Physician, Doctor Samui. Last reviewed: September 2026
Pubic lice, also called crabs, are tiny parasites that live in pubic hair and spread mainly through close skin-to-skin contact. Itching is the main symptom and usually starts one to three weeks after exposure. Treatment with a permethrin or pyrethrin lotion works in most cases, but you also need to treat your bedding and notify recent partners. If over-the-counter treatment is not working or you want a full STI screen, Doctor Samui’s walk-in clinic in Chaweng and 24/7 hotel visit service are both available.
You had a great night out in Chaweng. A few days later, you notice an itch you cannot explain, and a close look reveals something moving in your pubic hair. That is the moment most people reach for their phone and start searching.
Pubic lice are common, treatable, and nothing to panic about. They do not transmit disease. They do not mean you are dirty. They mean you had close contact with someone who had them, and now you need to deal with it. This guide covers what to look for, what to do right now, when pharmacy treatment is enough, and when you need a doctor.
What You Are Actually Looking For — Symptoms and Signs
The main symptom is itching in the pubic area, especially at night. This itch is your body reacting to lice saliva, not the lice biting through skin. That reaction takes time to build, so a first-time infestation often does not itch for one to three weeks after exposure. By the time you feel it, the lice have been there a while.
You may also see tiny blue-grey spots on the skin from louse bites. Look closely at the base of pubic hairs for small white or yellowish eggs called nits. The lice themselves are about the size of a sesame seed and move slowly. A phone camera in macro mode can help if you are not sure what you are seeing.
Some people have no symptoms at all. If a partner tells you they have pubic lice, get checked even if you feel fine.
How Pubic Lice Spread — and Why Condoms Do Not Stop Them
Pubic lice spread through direct, prolonged skin contact with an infested person. They cannot jump or fly. They crawl from hair to hair when two people are in close contact, which is why sexual contact is the main route of transmission.
Condoms do not prevent this. That is one of the most common misconceptions we hear at the clinic. A condom covers the penis, not the surrounding skin and hair where lice actually live and move. You can follow every other safe-sex precaution and still pick up pubic lice. This is not a failure of safe sex. It is simply how this particular parasite travels.
Who Is at Risk on Koh Samui
Anyone with close physical contact with an infested person is at risk. On Koh Samui, that includes couples on holiday, people enjoying the Chaweng nightlife scene, and anyone with a new partner during their stay. Tourists are especially exposed because they may not know a partner’s recent history, and a short island visit means encounters happen quickly.
Shared bedding and towels carry a smaller risk. Lice die within 24 to 48 hours off a human host, so properly laundered hotel linen is low risk. Budget guesthouses where laundering temperatures are low carry more concern. If you are worried, wash all personal items at 60°C or above.
When Crabs Spread Beyond the Pubic Area
Pubic lice usually stay where hair is coarser and closer together, but they can move. In men with body hair, the abdomen, chest, and inner thighs can be affected. Armpit hair is another site.
Eyelash infestation is less common but does happen, particularly in children. The standard insecticide lotions are not safe near the eyes. Petroleum jelly applied carefully to the lashes twice daily for a week can smother lice there. If you suspect eyelash involvement in yourself or a child, come in rather than trying to manage it alone.
Pubic Lice Treatment — What Actually Works
A permethrin 1% cream rinse or a pyrethrin-based lotion applied to the affected area and left for the time stated on the packaging is the standard first-line treatment. Wash it off, then use a fine-toothed nit comb to remove dead lice and eggs. Repeat the treatment after seven days to catch any eggs that hatched after the first application.
Pharmacy products in Koh Samui do contain these active ingredients, but availability varies by outlet. Apply the treatment to all affected hair-bearing areas, not just the pubic region. Do not use these lotions near your eyes.
If itching continues after two full rounds of treatment, the problem may be permethrin resistance. Some lice no longer respond well to standard over-the-counter products. Prescription alternatives such as ivermectin or malathion lotion are available and effective when standard products fail. We can prescribe these at the clinic after a short examination to confirm the infestation is still active.
What Happens If You Only Treat Yourself
Treating yourself without addressing the environment or your partners means re-infestation is almost certain. Wash all bedding, towels, and clothing used in the last 48 to 72 hours at 60°C. Anything you cannot wash, seal in a plastic bag for 72 hours. Lice cannot survive that long without a host.
The harder problem on holiday is partner notification. If your partner is still on the island, they need to treat at the same time you do. If they have already left Samui, send a message. It does not need to be a long conversation. They need to know so they can get treatment and stop the chain.
Should You Get Tested for Other STIs?
Yes, and we recommend it every time. Pubic lice spread through the same kind of intimate contact that transmits other infections. A significant number of people with pubic lice have a concurrent STI they are not aware of, including chlamydia, gonorrhoea, syphilis, or HIV, all of which can be present without obvious symptoms early on.
A same-visit STI screen at Doctor Samui’s sexual health clinic involves a blood draw and swab. Results come back within a day or two for most tests. Getting everything checked at once is simpler than coming back later, and it removes the doubt.
Getting Diagnosed and Treated on Koh Samui
If pharmacy treatment has not worked, you want to confirm the diagnosis, or you need a prescription alternative alongside a full sexual health screen, Doctor Samui’s Chaweng clinic is the straightforward option. Walk in without an appointment. Consultations are confidential, and we see pubic lice cases regularly.
If you would rather not travel to the clinic, our 24/7 hotel and villa visit service covers Chaweng, Lamai, Bophut, Maenam, Choeng Mon, and the rest of the island. A doctor comes to you, confirms the diagnosis, prescribes what you need, and can arrange pubic lice and STI testing at the same visit. English, German, and Hebrew-speaking staff are available.
If you think you have pubic lice, want to confirm the diagnosis, or need a prescription treatment not available at a pharmacy, Doctor Samui is here. Walk into our Chaweng clinic any time, or book a 24/7 hotel or villa visit anywhere on the island. We offer same-visit STI testing and handle everything with full confidentiality. Contact us through doctorsamui.com to arrange a consultation.
Frequently Asked Questions
Dr. Ponlawat Pitsuwan
Physician, Doctor Samui
a walk-in clinic based in Chaweng, Koh Samui, with 24/7 hotel and villa visits across the island. He sees tourists, families, and long-stay expats for sexual health concerns including STI testing, PrEP and PEP, pubic lice assessment, and discreet same-day consultations. His focus is straightforward, evidence-based care delivered in plain language.
