Skin Bends - Decompression Sickness in Divers

The Causes and Cures for Skin Bends

sunburned scuba diver
A sunburn or a skin bend? Skin bends are sometimes overlooked because some forms appear similar to a sunburn. Image copyright istockphoto.com, jcarillet

Decompression sickness can strike in many forms. One frequently overlooked form of decompression sickness is cutaneous decompression sickness, also known as skin bends. Some forms of skin bends may require recompression treatment in a hyperbaric chamber, while others may eventually disappear on their own. No matter what the type, all skin bends should be reviewed by a hyperbaric doctor. Here is some basic information on skin bends, including the different forms; how to recognize a skin bend; and other problems that this kind of bend may indicate.

What is Decompression Sickness?

The term decompression sickness describes any one of a variety of ailments caused by absorbed nitrogen coming out of solution in a person's body. In scuba diving, this happens because high levels of nitrogen are absorbed when a person is exposed to increased pressure underwater. (Click here for more information on nitrogen absorption and scuba diving.) If this excess nitrogen is not metabolized naturally as a diver ascends, it forms bubbles that can lodge in various parts of a diver's body, such his joints or skin capillaries. Keep in mind that decompression sickness is rare and unlikely when proper dive procedures are followed.

What is Cutaneous Decompression Sickness?

Most diving physicians agree that cutaneous decompression sickness is caused by nitrogen bubbles becoming lodged in the skin's capillaries. Alternatively, skin bends may also be caused by the body's defensive reaction to these tiny nitrogen bubbles, during which it releases histamines and other chemicals that mimic an allergic reaction.

Whatever the cause, skin bends usually appear within a few minutes to a few hours of surfacing.

Types of Skins Bends:

There are several different manifestations of skin bends. Some are more severe than others.

  • The Itchy Rash: The mildest form of cutaneous decompression sickness is a rash, most commonly located on the upper torso, chest, back, or shoulders. The rash appears similar to a sunburn and is usually itchy. Divers have described the itchy sensation as the feeling of tiny insects crawling on the skin. While this form of decompression illness is mild and may not require recompression in a hyperbaric chamber, all mysterious rashes that appear after diving should be reviewed by a dive physician. Scuba divers frequently overlook a decompression rash, attributing it to other factors or assuming it is not serious. However, as stated on the London Diving Chamber website, " To have a bend means that a day's decompression was not appropriate. To have many bends, even if only skin bends indicates potentially dangerous risk factors in need of identification." In other words, just because a bend might not require recompression does not mean it is not a problem.
  • Marbling or Cutis Marmorata: Cutis marmorata describes a more severe form of skin bends. The characteristic "marbling" of the skin in this type of decompression sickness is hard to mistake. Photos of cutis marmorata show bright red, purplish, or even bluish skin with an uneven, marble-like pattern. Like the rash form, this kind of cutaneous decompression sickness is most common on the chest, torso, back and shoulders. It has also been reported to be extremely itchy. The coloration may appear in patches, or in severe cases may begin on the chest and spread downwards. Unlike the rash form, cutis marmorata is considered serious; recompression is required in most cases. Cutis marmorata has been found in association with other, more serious forms of decompression illness, such as neurological decompression illness.
  •  Lymphatic Decompression Sickness: Divers can recognize lymphatic decompression sickness by a swollen area (or areas) that holds an indentation for a few moments when depressed. Also characteristic of lymphatic decompression sickness is a peculiar pitting of the skin over the swelling, similar to the pitted skin of an orange. Lymphatic decompression sickness has been reported to go away on its own. However, it will disappear more quickly with treatment. Like the other forms of skin bends, lymphatic decompression sickness may occur along with, or before, other more serious forms of decompression sickness. Any suspicious swelling after a dive should be investigated by a diving physician.

    The Importance of Recognizing Skin Bends:

    Divers should be able to recognize cutaneous decompression sickness so that they can take any necessary precautions, such as immediately breathing oxygen, seeking medical evaluation, or undergoing recompression. As with any other type of decompression illness, if a skin bend is recognized, a diver should refrain from any further dives until he has consulted a dive physician.

    Skin Bends Can Precede More Serious Problems

    Cutaneous decompression sickness symptoms have been known to manifest before or along with the symptoms of more serious types of decompression sickness, such as neurological decompression sickness. A diver who notices a skin bend and goes immediately to a diving physician will have a head start at treating any other symptoms that may arise.

    Time is of the essence when treating decompression illness; the sooner a diver is in the recompression chamber, the higher his chances of a full recovery. Recognizing a skin bend may be the first step to a timely and effective treatment.

    Skin Bends May Indicate a PFO

    A patent foramen ovale (or PFO) is a heart condition that is thought to cause a higher risk of decompression illness. (For more information on patent foramen ovale click here.) Diving physicians have begun to notice a possible correlation between cases of skin bends from dives well within the recreational dive tables and the presence of a PFO. Divers who have a history of skin bends would be well advised to test for a PFO.

    Preparation Is Nine-Tenths of the Battle

    Decompression sickness is rare. Most recreational divers will never experience a form of decompression sickness. This said, divers should learn about the different types and symptoms of decompression sickness so that they can react properly and efficiently in the unlikely event that a case of decompression sickness should arise. Skin bends may be one of the most common manifestations of decompression sickness, but it is frequently misidentified as a sunburn or other non-diving ailment and goes unreported. Skin bends can be a sign of improper dive procedures or a medical predisposition to decompression sickness such as a PFO. Although it may only be skin deep, cutaneous decompression sickness must be taken seriously.