What is biting on the beach in Nha Trang and how to treat the bites?

For allergic reactions to plankton bites, Fenistil gel applied to the rash helps. The rash typically builds for a couple of days then subsides if you avoid swimming during that time.

One traveler noted steroid creams aren't a great idea for plankton bites, and another reported that an unnamed cream they used caused a skin burn instead of relief.

For strong reactions to plankton bites, Suprastin (an antihistamine) taken for two days is enough to relieve redness and itching.

The culprits are sand flies — tiny dark insects that are nearly invisible to the naked eye. Bites take a long time to heal. The most effective relief reported is applying the liquid from an ammonia smelling-salts pen directly onto the bite spots.

The biting insects on Nha Trang beaches are so small they're nearly impossible to spot. Many travelers initially blame plankton or sand fleas, but the actual cause is tiny midges or sand flies. Individual reactions vary — some people show almost no marks, while others develop clearly visible bite spots.

Some beach bites in Nha Trang may come from plankton in the water rather than insects on land. Skin reactions vary significantly between individuals — some people show almost no marks while others have clearly visible welts.