Diver’s Knee Injury from Coral Leads to Skin Discoloration

A diver who said he’d been “pushed into” fire coral off the coast of Indonesia posted pictures of the resultant rash on social media and asked readers for advice in treating it.

Reddit user buckbuckmow posted two images of his knee, shown below, that he said were taken five days apart, on March 21 and 26, respectively.

In the first image, his knee appeared scraped, with a red, irritating rash. The second image appeared more ominous, with what appeared to be coagulated blood collecting just under his skin.

“Nearly a week ago I scraped my knee on what I believe was fire coral in Indonesia,” he wrote in the post. “It burned like crazy for the whole dive and afterwards.

“The first pic is from the day I got home (last Thursday) and this morning. It has become more painful and the scraped areas are turning black,” he wrote.

Coral poisoning
byu/buckbuckmow inscuba

The understandably concerned diver asked for input from other divers in the r/scuba subreddit with the heading “Coral poisoning.”

“Has anyone had this experience?” he asked. “I’ve made an appt with my [general practioner], but was wondering if anyone has experienced this.”

The post received numerous comments — the majority of them about as helpful as most social media comments are (which is to say, not at all) — including one that suggested buckbuckmow should “learn to step up your bouyancy [sic].”

Buckbuckmow responded that his buoyancy wasn’t the issue, as he’d been pushed into contact with the coral by a fellow diver.

Several users, however, said that they’d experienced a similar rash from fire coral and described it as both painful and long-lasting.

The original posted added a comment the day after his post with the results of his visit to his doctor.

“I saw my GP. He prescribed Bactrim and told me to take antihistamine,” he wrote. “The black is coagulated blood. All is well.”

Maria Rosa, an associate professor of biology at Connecticut College, told Newsweek that the images in the post resembled what she would expect to see from brushing up against fire coral.

However, she took exception to the heading on the post, saying that this was not a case of “coral poisoning.”

“Corals and jellyfish are in the same family of animals that are defined by having ‘stinging cells’ known as cnidocytes. These cells are on a hair trigger and release a venom to subdue prey, such as fish, for eating.”

“Fire coral is known for creating a very uncomfortable burning sensation, hence the name,” Rosa said. “It can result in a welt or these types of lesions, similar to what you get if stung by a jellyfish.”

In severe cases, Rosa told the outlet, fire coral can even cause paralysis in humans, but typically it causes a rash that goes away on its own in a few weeks.