Cake-Seeking Iguana Bites 3-Year-Old Girl, Leading To Mycobacterium Marinum Infection

When iguanas want cake, let them eat cake. That’s one of the take home messages from a case report entitled “Never get between an iguana and his cake: a cautionary tale of a subcutaneous mass following an iguana bite.” Jordan Mah, MD, from the Stanford University School of Medicine is scheduled to present this case report on April 18 at the European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) in Copenhagen, Denmark. Jordan Kit Mah, MD, from the Stanford University School of Medicine will be presenting this case of a reptile dysfunction that resulted in an infection.

It can be considered a “dysfunction” because iguanas don’t tend to bite humans. Instead, their diet typically consists of leaves, weeds, flowers, and fruits. But cake can make you (and apparently iguanas) do things that you normally won’t do. In this case, everything started when a 3-year-old girl was vacationing in Costa Rica, sitting on the beach eating cake. The girl presumably wasn’t vacationing by herself because 3-year-olds don’t tend to say, “I need a break from this stressful life of speaking in four-to-five word sentences and asking ‘why’ dozens of times a day and should book a vacation on Expedia.” While the girl was taking her sweet time on the beach, an iguana “suddenly ran up and bit her on the back of her left-hand before snatching the cake,” to quote a press release from the European Society of Clinical Microbiology and Infectious Diseases. Apparently, the girl had given the iguana her middle finger, so to speak, since the health professional at a local clinic found a not-too-deep wound on the back of her middle finger. She received a five-day supply of amoxicillin to cover possible exposure to Salmonella bacteria, which reptiles can carry. The would seemed to heal well over the next few days.

But this wasn’t a case of all’s well that ends swell. Five-months down the road, her parents noticed that she had developed some swelling, a small bump on the back side of her left hand that was progressively getting larger, more red, and somewhat tender over the ensuing three months. Eventually, the girl went to Stanford Children’s Health. An ultrasound of her hand showed that the lump appeared to be a cyst filled with fluid. However, when an orthopedic surgeon removed this lump, pus came out, suggesting this was instead the result of an infection.

A closer look at the tissue from this mass revealed necrotizing granulomatous inflammation. Now, necrotizing ain’t a good word to hear. You never want your date to say, “I found you rather necrotizing,” since necrotizing means causing death. So, necrotizing inflammation is when the inflammation is resulting in the death of tissue. Doctors also found Mycobacterium marinum in the mass, a microbe that tends to be resistant to common antibiotics such as amoxicillin. Therefore, the doctors started the girl on different antibiotics, rifampin and clarithromycin, that seemed to do the trick.

M. marinum is a very fishy pathogen as it’s more commonly known to cause an illness that resembles tuberculosis in fish. Infected fish can develop skin lesions or ulcers as well as bulging eyes and swelling of their abdomens. Getting cartoon-looking eyes is not a fun things. Neither are the other possible effects such as spinal deformities and sudden death.

Assuming that you are not a fish, you as a human can catch this bacteria too when you expose any open skin wounds to either fresh or salt water that’s been contaminated with M. marinum. You are not likely to get bulging eyes. Rather, skin lesions, such as nodules or ulcers, are more common. As seen in the case of the lizard’s tale mentioned earlier, without treatment, these skin lesions can possible last for months. When you have a strong immune system, these infections tend to stay localized to the skin and soft tissue. Occasionally, especially when your immune system is much weaker, this pathogen can spread to other parts of your body like your bones and joints. Death is possible, but is quite rare and usually occurs only in those with weakened immune systems.

Iguana bites are not common. You don’t hear of too many people complaining, “There I was minding my own business during the job interview, when an iguana bit me. Of course, since it was the iguana who was interviewing me, I didn’t say anything.” Iguana usually should be pretty harmless towards you as long as you are not a leaf. Therefore, you don’t have to spend your days worrying, “Is an iguana gonna bite me? Is an iguana going to bite me,” while hoarding rolls toilet tissue. That doesn’t mean that you should go around kissing iguanas. They can carry various bateria such as Salmonella enterica, Serratia marcescens, and Staphylococcus aureus. Although this was the first reported case of a M. marinum after an iguana bite, apparently iguanas can carry such a pathogen as well.

This cake and iguana story may have had many layers. But it does provide a reminder that you should be careful when carrying cake. You never know when some co-workers, friends, family, reptiles, or anyone who may be a combination of these may start eyeing your cake as if it were a hot person on Tinder. After all, cake has a way of saying, “Do you want a piece of me?” You can have your cake and eat it too, as long as there aren’t any iguanas around.