Sea Lice in Cancun | Prevention and Treatment

Sea Lice in Cancun
What a Sea Lice attack looks like.

If you are visiting between March and August then you should know about sea lice in Cancun. More importantly you should know how to avoid them, and what to do if they get you.

Below is information on the sea lice season in Cancun when they are likely to be at their most abundant. Plus advice on how to prevent sea lice attacks in the first place.

Read our explanation of Safe Sea Lotion. Safe Sea is widely regarded as the best preventative sea lice measure around. Safe Sea lotion is not generally available in Cancun, so it is worth taking a bottle or two if you intend to visit Cancun during sea lice season.

It will help you avoid this itchy pest that could spoil your vacation. Scroll down for details.

If you are unfortunate enough to have a painful meeting with sea lice in Cancun then this article also explains the best sea lice treatment methods. We also have a few tidbits of advice on where to buy any necessary creams and medication locally in Cancun.

We aim to provide all the information necessary to make sure your trip to Cancun goes without an itch. 🙂

Are There Sea Lice in Cancun?

Yes, at certain times of year there are. Sea lice are known locally as Agua Mala (bad water) or pica pica (itchy, itchy) and throughout the world as Seabather’s Eruption.

They can be responsible for a painful itchy rash when swimming in the Caribbean Sea off the beaches of Cancun.

What Are Sea Lice?

Sea lice in Cancun are in fact, not lice at all. Don’t confuse them with the parasitic louse that affects fish. Also, they are not sand fleas, sand lice etc that live in wet sand.

They are the microscopic larvae of the thimble jellyfish (Linuche unguiculata) and around the size of speck of pepper. They float freely through the warm seas during the late spring and early summer months.

They are translucent which means that combined with their size of less than a millimeter they are almost impossible to see with the naked eye.

Here’s a picture taken in Cancun that I took myself of the adult thimble jellyfish.

Thimble Jellyfish in Cancun
Adult Thimble Jellyfish in Cancun

The adults appear as long thin ribbons stretching for hundreds of yards.

You can be sure that if there are adults around there will be babies too!

Areas of bare skin normally escape unscathed.

But, if they get through your bathing suit the fabric acts as a net, pisses them off and their venom can be triggered.

A Sea Lice attack will cause large red welts and blisters, often in the most sensitive of places!

SafeSea Lotion: Sea Lice Attack Prevention

The sensible traveler should always take along a few medications when traveling abroad. If you’re traveling to Cancun between March and August then you should definitely consider buying Safe Sea.

After all, you’ll be taking sunscreen with you and why not take one that not only protects you from the sun, but can also defend against sea lice?

As an Amazon Associate I earn from qualifying purchases.

Safe Sea is not a treatment it is a preventative measure and therefore should not be applied after an attack has already occurred.

Safe Sea is the World’s only solution against marine stingers and not only does it help prevent a sea lice irritation but it also protects against most other jellyfish too. Featured on the BBC program Tomorrows World and in National Geographic Magazine.

Clinical trials have proven that Safe Sea is a topical barrier cream which is effective at preventing >80% jellyfish stings under real-world conditions.

Safe Sea is available with several degrees of Sun Protection Factor and has been dermatologically tested for sensitive skin. Amazon also offers Safe Sea products with zero sunblock for divers, sprays and a range especially for kids.  Click Here For The Full Range.

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You may also be able to purchase Safe Sea at places such as small local dive shops in your area. But one place you will NOT find Safe Sea is in Cancun.

How to Prevent Sea Lice From Spoiling Your Vacation

In order to help prevent sea lice affecting your Cancun vacation it is first important to understand how and why the thimble jellyfish larvae trigger their nematocysts (‘stingers’ to non biologists).

Then see what you can do by your own actions in order to minimize the risk.

Why Do Sea Lice Sting?

Each larva has many of these nematocysts or stinging cells located all over its body. Pressure alone is often enough to cause them to fire.

The pressure between your body and your swimsuit as friction is caused by the action of swimming in the Ocean, is enough to provoke them into firing.

Being trapped in body creases such as the joints of the arms and legs, or even against your neck because of long hair, annoys the hell out of them.

Increased friction such as may be caused by sitting on a surfboard, wearing a wet costume on a lounger, on a bus or in a taxi increases the risk. These critters live long after you have left the Ocean.

What Can I Do to Decrease the Risk of Sea Lice Stings?

When it comes to sea lice, less is more. Because the stinging action is triggered mainly by swimsuits then I would recommend ladies swim naked or at least wearing only a small thong 🙂

Seriously though, the smaller the amount of skin covered the smaller the area of risk exposed. So, certainly avoid T-shirts or long baggy shorts.

When you’ve left the water then instead of showering in fresh water with your suit on, make your way back to your room and shower thoroughly after taking off your costume. Then wear a dry change of clothes to go back to the beach, pool or bar.

If you’re away from your room, bring a spare costume with you and change into it before you shower in the fresh water. Wear a dry costume and shower in that. You’ll soon dry off again in the hot Cancun sun.

Swimming costumes that have been used during sea lice outbreaks should be cleaned with detergent and heat dried. If you just throw your suit on the balcony and use it the next day, chances are there will be critters left inside, and they won’t take kindly to their night on the tiles.

There is some evidence that suntan lotion inhibits the firing of the stingers, and more evidence that the special formulae of Safe Sea is more effective than regular lotions.

If you have a history of severe reactions then consider confining your swimming activities to the pool if a confirmed outbreak is known of.

Sea Lice Season in Cancun

The season for Sea Lice in Cancun extends all the way through from March until August. The highest risk months are April, May, June and July. Outbreaks are sporadic though and not normally consistent throughout the whole of the sea lice season.

The best source of warnings for when outbreaks are happening are those in the area. Talk to other vacationers, the lifeguards and in many cases other hotel staff will know.

Look out for leaflets handed out either on the beach or in your hotel lobby.

Areas Where Sea Lice in Cancun Attacks Are Most Prevalent

In Cancun, the area along the side of the 7 as it is known is the area where most outbreaks occur. This is where the ocean is rougher and faces the open sea.

On the bay side of Cancun (the top of the 7) the waters are calmer and the Cancun mainland is shielded by Isla Mujeres.

You may be more familiar with the high risk locations if I explained that the side of the 7 is the area between Km 8 Punta Cancun, southwards right to the end of the hotel zone by Club Med at Km 20.

You should note that during early outbreaks adult jellyfish may be seen in the ocean. However, it is the larvae and not the fully grown jellyfish that are responsible for the itchy rashes.

Just because there are no adult jellyfish are visible it does not mean that the microscopic larvae are not.

Sea Lice Attack Symptoms

Skin irritation becomes noticeable between 4 and 24 hours after swimming if you’ve been exposed to sea lice. Some people have reported a prickling feeling while in the water.

A sea lice rash is not a pretty sight. Large red spots, or welts begin to form and can blister and are accompanied by intense itching. The number of spots can be in the hundreds. Irritation normally resides within a week.

Mainly due to the itchiness you may have trouble sleeping. Other, more rare, symptoms can include, nausea, vomiting, diarrhea, headache, muscle spasms, fever, and a general sense of malaise.

Ouch! The Sea Lice Got Me. What Do I Do Now?

Well, a sea lice irritation is a kind of dermatitis i.e. an inflammation of the skin. Treatment methods for sea lice attacks are similar to other kinds of dermatitis such as eczema.

An antihistamine such as diphenhydramine will soothe the itching plus a hydrocortisone cream of 0.5% should be applied.

If the effect is severe, then a corticosteroid steroid cream may be considered. I am not 100% sure but I suspect this will not require a prescription in Cancun, not a lot of things do!

For comfort applying calamine lotion will also help.

If the situation is severe then Doctors advice should be sought. Remember, it is possible that any developing rash while on your vacation may not be due to a sea lice attack and could be something more serious.

Typically though, if a rash develops within 24 hours following swimming in the ocean between March and August, then there is a good chance they got you. Particularly if you didn’t follow the advice contained above about sea lice prevention.

You should also remember that this is not contagious, so if other members of your group and/or other vacationers are showing similar symptoms you can bet that it is related to sea lice.

But I’m in Cancun and Don’t Know Where to Get This Stuff?

Cancun Pharmacy
Cancun Pharmacy

Yes you’re in Cancun, but we still have pharmacies, and we also have Doctors. Most hotels will have a Hotel Doctor either resident or on call, but these can be expensive and IMHO unnecessary for a sea lice attack.

In the Cancun Hotel Zone there are smaller pharmacies who may also have an on site Doctor and may have what you require. The most common pharmacy chains in Cancun are:

  • Ahorro
  • YZA
  • Farmacia Similares (generic drugs at a cheaper price)

The large supermarkets such as Walmart, Chedarui and Soriana all have large pharmacies with qualified pharmacists. They will probably have a larger range of products than the smaller hotel zone pharmacies.

These supermarkets are all located downtown.

Walmart and Chedarui are easy to find. You can catch the R1 bus to Walmart, and Chedarui is also on the bus route – you’ll see it on your left-hand side almost as soon as leaving the main Hotel Zone Avenue.