Marine Stings & Bites in Keiki — Medicaid (QUEST) Accepted

Living in Hawaiʻi means our keiki grow up in the ocean — and that means the occasional sting or bite. Most are painful but not dangerous, and knowing the right first aid (which has changed in recent years) makes all the difference. This is the page mainland guides can’t give you, because these are our waters.

Box jellyfish — and the after-the-full-moon pattern

Box jellyfish arrive on many Oʻahu south- and leeward-facing shores — Waikīkī, Ala Moana, Hanauma Bay — on a remarkably predictable schedule: roughly 8 to 10 days after the full moon, as tracked by the Waikīkī Aquarium’s box jellyfish calendar. Checking that calendar before a beach day is one of the simplest ways to protect your family. Stings cause an immediate burning line-shaped welt.

First aid has changed — do this

Research from the University of Hawaiʻi has overturned some old advice. For a box jellyfish or Portuguese man-of-war (bluebottle) sting, the current best first aid is: rinse the area with vinegar, gently pluck off any visible tentacle pieces with tweezers, then apply heat — hot water around 113°F (45°C) or a hot pack — for about 45 minutes. The UH team found that some traditional steps — rinsing with seawater, scraping, and applying ice — actually made stings worse. Many lifeguard stations keep vinegar on hand.

Centipedes and other island bites

Hawaiʻi’s centipedes deliver a genuinely painful bite that frightens children. Most are treated at home with washing, a cool or warm compress for comfort, and pain relief; watch the site for spreading redness or signs of infection over the next days.

When a sting or bite is an emergency

Any sting or bite can rarely trigger a severe allergic reaction (anaphylaxis). Call 911 for trouble breathing, swelling of the face, lips, or tongue, widespread hives, vomiting, fainting, or a child who looks very unwell — these can follow a sting within minutes. A sting across a large area of a small child, or in the mouth or near the eyes, also deserves urgent evaluation.

How we approach it at Ohana Care Clinic

We help island families sort the routine ouch from the true emergency, and a telehealth photo often settles it fast. We hold this with aloha and mālama — practical, calm care for growing up in and around the sea.

Getting care by telehealth

Most of our care at Ohana Care Clinic happens by secure video across Hawaiʻi. A new primary-care or pediatric patient is seen in person for the first visit at our Hilo clinic; after that, many follow-ups and quick questions work well by video. When your keiki has a rash, sting, or other concern, a photo during a video visit often tells us whether they need to be seen in person.

When to get help now

Call 911 or go to the nearest emergency room for trouble breathing, swelling of the face or lips, widespread hives, fainting, or any reaction that looks life-threatening after a sting or new exposure. When in doubt, call us at (808) 867-8002 or use our symptom checker for after-hours guidance.

Medically reviewed by Donna Leonard, MSN, APRN, FNP-C, pediatric nurse practitioner, and George Mackel, MSN, APRN, NP-C, PMHNP-BC, CARN-AP, President & Owner of Ohana Care Clinic.
Date published: July 2, 2026 · Last reviewed: July 2026 · Citations verified: July 2026

This article is general health education from Ohana Care Clinic, reviewed by Donna Leonard, MSN, APRN, FNP-C, and George Mackel, MSN, APRN, NP-C, PMHNP-BC, CARN-AP. It is not a substitute for a personal evaluation by a qualified clinician who knows your child’s situation, and reading it does not create a provider–patient relationship. If you think your child may have a medical condition, reach out to us or another licensed provider. In an emergency, call 911.

References

University of Hawaiʻi at Mānoa, School of Ocean and Earth Science and Technology. (2017). SOEST scientists scrutinize first aid for man o’ war stings. https://www.soest.hawaii.edu/soestwp/announce/press-releases/soest-scientists-scrutinize-first-aid-for-man-o-war-stings/

Waikīkī Aquarium. (n.d.). Box jellyfish calendar. University of Hawaiʻi. https://www.waikikiaquarium.org/interact/box-jellyfish-calendar/