Sandflies (Chitras), Jellyfish and Other Nuisances in San Blas

The nuisances that really bother visitors in San Blas are small ones: chitras, tiny biting flies that come out around dusk and dawn when the breeze drops; the occasional sting from a jellyfish or fire coral; sea urchins on rocky and reef bottoms; and the sun. Repellent, long sleeves at dusk, water shoes and keeping off the reef prevent most of it.

None of this is a reason to skip the trip. This page is general information and basic first aid, not medical advice; for anything beyond a minor bite or sting, see a doctor.

What chitras actually are

In Panama, chitra is the everyday name for very small biting flies, and the word covers more than one insect. Part of what people call chitras are biting midges of the genus Culicoides, known elsewhere in Latin America as jejenes. The Pan American Health Organization describes them as 1 to 5 mm long, small enough to pass through ordinary mosquito netting (PAHO). Panama’s health authorities also use chitra for phlebotomine sand flies, a different insect.

You rarely see them coming. What you notice is small, red, very itchy bumps, often in clusters on ankles and arms, that can itch for days. English speakers call them sandflies or no-see-ums.

When and where they are worst

• Time of day. PAHO notes that Culicoides are most active towards the end of the afternoon and can carry on into the night. In practice, sunset and the first hour after it are when visitors get bitten, with a second round around dawn.
• Wind. These are weak fliers. A steady sea breeze keeps them down; the still, humid moments when the wind dies are when they appear.
• Vegetation and damp ground. Their larvae develop in moist soil, decaying leaves and standing water, so islands with more trees, mangrove edges and the mainland coast tend to have more of them than an open, breezy sand cay.

So a day visitor on the beach at midday may never notice a chitra, while someone staying overnight meets them at sunset; our overnight stays guide explains what the cabins are like.

How to avoid chitra bites

• Use an insect repellent approved by health authorities, following the label, and reapply after swimming. Put it on before sunset, not once you are already being bitten.
• Cover up at dusk. Light long sleeves and long trousers, as PAHO recommends, do more than any product. Ankles are the favourite target, so socks or trousers that reach the foot help.
• Sit in the breeze. Facing the open water, away from bushes and wet sand, makes a real difference at sunset.
• Do not count on an ordinary mosquito net. Midges can pass through standard mesh; a fine-mesh net works better if you are sensitive to bites.
• Do not scratch. In heat and salt water a scratched bite can get infected. Ask a pharmacist for an anti-itch cream before you travel: there are no pharmacies on the islands.

When a bite deserves a doctor

Almost every chitra bite is just an itchy nuisance. There is one exception worth knowing. Panama’s health authorities link the bite of an infected sand fly, also called chitra, to cutaneous leishmaniasis, a parasitic infection, and in 2022 the Ministry of Health listed Guna Yala among the areas with the most cases (Panamá América). Its usual sign is a skin sore at the bite site that takes weeks or months to heal.

So the practical rule is simple: if a bite turns into a sore that does not heal over the following weeks, see a doctor and mention that you were in Guna Yala. Mosquitoes are a separate question, covered in is San Blas safe?, including what health authorities say about malaria.

Jellyfish, fire coral and other stings

Most days in San Blas nothing in the water stings anyone. Still, the Caribbean has a few things worth recognising:

• Jellyfish can drift in with currents and wind. Give any you see plenty of space: tentacles trail well beyond the body.
• Fire coral is not a true coral but a relative of jellyfish that grows on reefs, often as yellowish-brown crusts or branches. Touching it produces a burning sting. It is one more reason never to touch, stand on or hold on to the reef.
• Tiny larvae sometimes cause an itchy rash under swimwear, known as seabather’s eruption or “sea lice”. Rinsing off and changing out of a wet swimsuit soon after swimming helps.

A long-sleeved rash guard is the simplest protection: it covers skin that would otherwise be stung or burned. If your captain says not to swim at a spot that day, listen. For what lives on the reefs, see our marine wildlife guide.

What to do if you are stung

The NHS gives clear first-aid steps for jellyfish and other sea-creature stings (NHS):

1. Get out of the water calmly and tell your guide.
2. Rinse with seawater, not fresh water.
3. Remove tentacles or spines with tweezers or the edge of a card, never with bare hands.
4. Soak the area in water as hot as you can tolerate for at least 30 minutes, or use hot cloths, without scalding the skin.
5. Take ordinary painkillers if needed.

Do not urinate on the sting and do not apply ice. The NHS also advises getting medical help after a sting in a tropical country, and treating difficulty breathing, chest pain, severe swelling, vomiting or light-headedness as an emergency. In San Blas that means telling your guide at once, because there is no clinic on the islands and help is hours away.

Sea urchins

Black, long-spined sea urchins live on rocky bottoms, reef edges and seagrass. Step on one and the spines break off in your foot; painful, but rarely serious. Water shoes when wading over anything that is not clean sand, and swimming rather than walking across shallow reef, prevent almost every case. If it happens, remove the spines you can reach with tweezers, clean the wound well, soak it in hot water, and see a doctor if spines are deep, near a joint, or the area becomes red and swollen.

The quick reference

Nuisance	When or where	Prevention	If it happens
Chitras	Dusk and dawn, still air, near vegetation	Repellent, long sleeves, sit in the breeze	Do not scratch; a doctor if a sore will not heal
Jellyfish and fire coral	Occasional, in the water and on reefs	Rash guard, never touch the reef	Seawater rinse, remove tentacles, hot water
Sea urchins	Rocky bottoms, reef edges, seagrass	Water shoes, swim instead of wading	Remove spines, clean, hot water, doctor if deep
Sun	Every hour from mid-morning	Reef-safe sunscreen, hat, shirt, water	Shade, fluids, cool the skin

The sun is still the main one

Of everything on this page, the problem that most often spoils a San Blas day is sunburn, not insects or stings. Our health and safety guide covers sun, dehydration and the distance to medical care, and the packing guide lists the small kit: repellent, reef-safe sunscreen, a rash guard, light long sleeves, water shoes and tweezers.

Frequently asked questions

Are there sandflies in San Blas?

Yes. Panamanians call them chitras: tiny biting flies that are most active around dusk and dawn, especially when the wind drops and near vegetation. On an open, breezy cay at midday you will rarely notice them; at sunset on an overnight stay you probably will.

Are there jellyfish in San Blas?

Occasionally, as anywhere in the Caribbean, and fire coral on the reefs can sting too. Most days nobody is stung. A rash guard and keeping your hands off the reef prevent most problems; if you are stung, rinse with seawater, remove any tentacles without bare hands and soak in hot water.

What should I do if I step on a sea urchin?

Get out of the water, remove the spines you can reach with tweezers, clean the wound and soak it in hot water. See a doctor if spines are deeply embedded or near a joint, or if the area becomes red, hot or swollen over the following days.

Should I worry about chitra bites?

Usually not: they itch for a few days and fade. But Panama’s health authorities link some sand fly bites to cutaneous leishmaniasis, so if a bite becomes a sore that does not heal over several weeks, see a doctor and mention you were in Guna Yala.