Permethrin Cream for Pubic Lice: How to Use It and When to Repeat Treatment

You are two days into a Pattaya holiday and the trip is going well. Then you notice the itch. Not the usual kind. The persistent, maddening kind, low down, worse at night. You check. You see something moving. That is a rough moment, and I will not pretend otherwise. But it is also a very treatable problem, and walking into Doctor Pattaya or calling for a hotel visit gets it sorted fast, usually in a single consultation.

Pubic lice, sometimes called crabs, are a sexually transmitted infestation. They spread through close physical contact, almost always sexual. They are not a sign of poor hygiene and they are not a crisis. Permethrin cream handles the job in most cases. What I want to do here is walk you through exactly how to use it, what to expect afterward, and what to do if the itch sticks around.

What Pubic Lice Are and How You Know You Have Them

The main symptom is intense itching in the pubic area, often worse at night. You may also notice small blue-grey spots on the skin from bites, or tiny rust-coloured specks in your underwear. If you look closely at the hair, you can sometimes see the lice themselves or their eggs, called nits, stuck firmly near the base of the hair shaft.

Pubic lice can also spread to other coarse body hair: thighs, abdomen, armpits, and beard. Head hair is usually spared. I will come back to the eyebrow and eyelash situation separately, because that case needs a different approach entirely.

One thing worth knowing: pubic lice are sometimes confused with scabies or folliculitis, both of which also cause itching in similar areas. Getting a clinical confirmation before you treat means you are using the right product for the right problem.

How to Apply Permethrin Cream for Pubic Lice

Permethrin 1% cream rinse is the standard first-line choice recommended by the CDC. The 5% formulation is more commonly used for scabies, so check the label carefully.

You do not need to shave first. Shaving will not remove the nits, and the CDC confirms it does not replace chemical treatment. Apply the cream to dry pubic hair and the surrounding skin. Work it in well, covering the hair from root to tip.

Leave it on for exactly ten minutes, then rinse off thoroughly with water. Do not leave it on longer hoping for a better result. After rinsing, use a fine-toothed nit comb to work through the hair. This lifts out dead lice and any remaining egg casings and makes a visible difference to the outcome.

When to Repeat Permethrin Treatment

One round is usually enough if applied correctly and all partners are treated at the same time. But permethrin has limited activity against eggs. Some eggs may survive the first treatment and hatch in the days that follow.

Check the area on day seven. If you can see live lice moving, repeat the treatment using the same method. One repeat at seven days is the standard protocol. You should not need a third round.

If you are still seeing live lice after two full rounds, that is the time to see a doctor. Second-line options are available. Do not keep applying permethrin repeatedly on your own.

Why Permethrin Appears Not to Work

This comes up often. Someone applies permethrin, still itches a week later, and assumes treatment failed. Most of the time, the problem is not the permethrin.

The most common reason is re-exposure. If a partner was not treated at the same time, re-infestation can happen within days. Incomplete application is the next most common reason, followed by not washing bedding and clothing promptly after treatment.

True permethrin resistance in pubic lice exists but is far less common than those three causes. Before concluding the treatment has failed, go through the checklist: did you apply it correctly, did your partner treat on the same day, and did you wash bedding in hot water immediately? If any answer is no, repeat the process correctly before switching medications.

Side Effects and Normal Reactions

Permethrin cream commonly causes mild burning or stinging on application. Some skin redness is also normal. These settle quickly after rinsing off.

The itch may continue for days or even two weeks after a successful treatment. This is your skin’s ongoing allergic reaction to the louse bites, not a sign of live lice still being present. It does not mean the treatment has failed. If itching is still significant two weeks after treatment and no live lice are visible, a mild antihistamine can usually manage it. Check with a doctor before using anything else in the area.

Treating Your Partner and Sorting the Environment

Your partner needs to be treated on the same day. Treating yourself while a partner goes untreated almost guarantees re-infestation. The standard look-back period for partner notification is one month.

Machine wash all bedding, towels, and clothing at 60°C or higher, then dry on a hot cycle. If you are in a hotel in Pattaya or Jomtien and do not have access to laundry, seal the items in a plastic bag for 72 hours. Lice cannot survive without a host for more than two days.

Mattresses and upholstered furniture do not need to be sprayed with insecticide. Pubic lice do not survive long off the body and do not infest the wider environment the way head lice might.

Special Cases: Lice in the Eyebrows or Eyelashes

If lice have spread to the eyebrows or eyelashes, do not use permethrin there. The standard approach is petroleum jelly applied to the lashes twice daily for ten days. This suffocates the lice without harming the eyes. Nits should be removed manually with tweezers or a fine comb.

An ophthalmology review is recommended if the infestation is significant. This is one situation where self-treating at a pharmacy without a clinical review can go wrong. If you think lice have reached your eyelashes, come in for a proper assessment.

Permethrin Alternatives for Pubic Lice

If two correctly applied rounds of permethrin have not worked, second-line options are available. Malathion 0.5% lotion is applied for eight to twelve hours before rinsing. Pyrethrins with piperonyl butoxide is another topical option, though it shares a similar mechanism to permethrin and may not help in true resistance cases.

Oral ivermectin is a prescription tablet sometimes used for resistant cases. In Thailand, it requires a prescription, so a doctor consultation is the route to get it. None of these alternatives should be used without a clinical review if you are pregnant, breastfeeding, or treating a child.

Should You Get Tested for Other STIs?

Yes. Pubic lice are sexually transmitted, and their presence is a clear signal that other STI exposure may have happened around the same time. Both IUSTI guidelines and the CDC recommend STI screening when pubic lice are diagnosed.

This is not about alarm. It is about being thorough. Gonorrhoea, chlamydia, syphilis, and HIV can all be present without obvious symptoms in the early weeks. Getting tested while you are already at a clinic takes around thirty minutes and gives you a clear picture.

At Doctor Pattaya, our sexual health screening runs alongside pubic lice treatment in a single consultation. Same visit, confidential, no separate appointment needed.

Getting Permethrin Cream and Treatment in Pattaya

Permethrin is available at some Thai pharmacies, but concentration labelling and brand names can differ from what you know at home. Buying the wrong product or applying it incorrectly is a common reason treatment fails the first time.

For a first episode, or if treatment has already failed once, a walk-in consultation is the smarter move. A doctor can confirm the diagnosis visually, rule out scabies or folliculitis, and get you the correct product and strength. If you need a second-line treatment, that requires a prescription anyway.

Doctor Pattaya is open 24 hours, seven days a week, and sees tourists, expats, and residents across South Pattaya, Jomtien, Pratumnak, and Naklua. Hotel visits are available if you would rather be seen where you are staying. Our STI treatment and sexual health pages have more detail on the full range of services available, including same-visit screening for anyone who wants a complete check while they are already in.