Rash After Diving

Question:

I recently introduced my wife to scuba diving. On a few of the dive trips we've taken she's developed rashes on her body, especially around her inner thighs, waist and chest. We observed this usually happens after she has a quick rinse with fresh water. But if she rinses off with seawater, the rashes don't occur as frequently. The rashes are painful but they fade after two or three days.

Answer:

As a general rule, decompression illness (DCI) should be considered a possible cause of any rash that appears within 24-48 hours after diving. This is why it's important a diving physician is consulted and informed of the details of the dives that preceded the appearance of the rash, and any other symptoms that may be present. If DCI can be excluded as a likely cause, then we must look at local causes such as personal allergies, equipment problems, and environmental causes.

A diving physician would ask about allergies and whether other people were affected similarly. Allergies are very specific, as is contact dermatitis. The doctor would also consider what she was wearing during the dives. If she was diving in the tropics, she may be wearing only swimming gear. Then the likelihood of "aquatic dermatoses" should be considered. The causes include coelenterates (jellyfish, corals, and hydroids); algae, cerceriae (parasitic lavae); and many degradation marine proteins that float in the sea at different times of the year.

If only the area under the bathing suit was affected this could indicate contact dermatitis from the suit or irritants under the clothing. If the area under the suit was relatively free of inflammation and the affected area was exposed to the ocean, many other aquatic organisms, irritants and allergies would need to be excluded. If the bathing suit was free of injury but she was wearing a protective suit over a swimsuit, and if it was this area that was involved, then irritants or allergies from the suit material would be incriminated.

A thorough history as described will indicate both the diagnosis and prevention. Without it, it's guesswork.

Answer provided by Dr Carl Edmonds who is a senior Medical Advisor for DAN Asia-Pacific.