Ocean City’s beach patrol issued a report Thursday of stinging “sea lice.” (Town of Ocean City)

One of the apparently lesser-known of the pests, nuisances and annoyances that can spoil summer and ruin a day at the beach came to light this week in Ocean City. They are known as sea lice.

They are small, they are pesky, and they can be found in the sea. Scientists, however, say they are not really lice, but larvae, one of the developmental stages of another seaborne creature often regarded as undesirable: the jellyfish.

A woman from Potomac, Md., who was at Ocean City this week said two of her children suffered a sea-lice attack. At first the two found the water fine, she said, but after a couple of waves crashed, the sea lice began to sting.

“They were awful,” said Laura Gwyn. “My daughter had them all in her hair. They bite and itch.” The stinging larvae “got into their clothes and shoes,” she said.

On Thursday, Ocean City’s beach patrol reported the problem on its Facebook page.

“We have been getting a lot of calls about sea lice today,” the beach patrol said, adding that the offending organisms were also detected elsewhere along the Eastern Seaboard.

Their potential for annoyance appeared plain.

“They can get into bathing suits while swimming and cause discomfort,” the beach patrol said in its posting.

The advice given was “to rinse with fresh water.”

A scientific study published in the Journal of Emergency Nursing in 1993 indicated that “sea lice” was a name given to the condition known as “seabather’s eruption.”

It reported that from March to August, some of those entering the waters of Florida’s southern Atlantic coast broke out in rashes. The skin eruption was found principally in areas covered by swimsuits.

No larger than a pinhead, the offending organisms are apparently trapped by bathing suits. The fabric plays the role of a net.

According to the study’s authors, Mary T. Russell and Robert S. Tomchik, the problem had existed for at least the past 100 years but had been identified only relatively recently.

In Florida, the authors said, winds and currents may apparently bring the organisms closer to shore at times.

It was not clear if the infestation persisted Friday at Ocean City.