We all know that a blue-ringed octopus like this one can inflict serious injury, but what about other octopuses? PAYAL RAZDAN offers a thought-provoking case history…
The diver was a generally healthy, 32-year-old woman with 130 lifetime dives. Her medical history included no allergies or other health problems.
She had just completed her second dive on the second day of a series of dives.
During the dive, the diver’s buddy collected what he thought was an empty moon-snail shell. The divers didn’t realise that a juvenile giant Pacific octopus (Enteroctopus dofleini) had taken up residence in the shell.
Before she could put the octopus back in the water, it bit her on the back of her left hand three times in the same place. She described the bites as surprising, and feeling similar to bee-stings.
The wound bled moderately, and the diver rinsed it first with salt water and then, 40 minutes later, with soap and fresh water. Swelling appeared within 30 minutes and became severe within about an hour.
About four hours later, the diver did another dive. On surfacing she was nauseous and vomited, symptoms she had not previously experienced after diving. The nausea resolved quickly, and she conducted five more dives over the next two days, despite significant swelling and compromised mobility that lasted for about four days.
The diver wore a drysuit and neoprene wet-gloves on every dive. When not diving, she kept the wound dry and applied an over-the-counter antibiotic ointment to it.
She also took an over-the-counter antihistamine and applied crushed aspirin to the skin surrounding the puncture site (not directly on the wound), but none of these treatments provided any relief. Significant itching and pain reached their peak five to six days after the incident.
About three days after the bite had occurred, the wound became infected and developed into a dark, quarter-inch lesion surrounded by a raised red area. Black-green discoloration surrounding the lesion appeared about nine days after the incident. Moderate pain and significant itching and swelling lasted for more than a month.
The lesion took some seven weeks to heal, although pain, sensitivity to touch and itching lasted for three months, with minor flare-ups still occurring four to five months after the incident, usually after exercise or early in the morning.
Six months after the incident, a tissue nodule remained at the bite site.
Recently, however, scientists have come to understand that all octopuses may be venomous to some degree. Medical literature indicates that bites by octopuses of the same class as the giant Pacific have resulted in ulceration.
The small puncture wound developed into what appeared to be an ulcerous lesion, similar to one that developed following a common octopus bite documented in a 2011 case report.
The delay in proper wound care may have been a complicating factor. DAN recommends washing marine bites immediately with soap and clean water to minimise the risk of infection, which can impair healing and lead to significant tissue damage.
Divers should not dive with open wounds, because exposure to the aquatic environment can increase infection risk.
Monitoring the wound site is important, because signs of infection can appear from within hours to several weeks following an injury.
The immediate swelling the diver experienced may have been a consequence of the initial trauma, the exposure to myriad antigens that followed and/or toxins. The prolonged symptoms were most likely a result of infection.
The drysuit wrist-seals may have been a secondary complicating factor. The swelling was probably the result of an acute inflammatory reaction, but the tight-fitting seals may have compromised distal perfusion or blood flow, further exacerbating symptoms.
In addition to inflammation of the affected area, other symptoms of infection include pain, redness and immobilisation. These symptoms can be remembered using the acronym PRISH: pain, redness, immobilisation (impaired function), swelling and heat (elevated warmth of the infected area).
The cause of the diver’s nausea on completing the dive is unclear.
A third complicating factor in this case may have been the delay in medical care. DAN advises divers to treat wounds caused by marine life like any other animal bite, and seek prompt medical attention. In this case, the wound was evaluated 10 days after the incident, delaying treatment that might have limited progression of the symptoms.
Initially the doctor prescribed a 10-day course of the antibiotic levofloxacin, but evolving symptoms and progressing discoloration prompted the addition for 10 days of another antibiotic, amoxicillin and clavulanate, along with an antihistamine to manage the itching.
This incident underlines that timely treatment of wounds can reduce risk of serious infection. Whenever possible, divers should photograph wounds, because images can help medical staff provide more effective and efficient care.