Pins and Needles After Surfacing

(Q) After a recent dive trip, a friend experienced "pins and needles" sensation on the back of her thighs which lasted for a long time after surfacing. She has experienced this before after diving in relatively cold water (24 C, yeah I know it's nothing to most of you but the water is usually 28-30 C here in Thailand). Her diving was conservative. In addition to deep stops and 1 minute spent for each 3m ascending, there were stops of 3 minutes at 6m and 3m during the last two days of diving. Is this perhaps something which she should be concerned about? Any advice would be greatly appreciated.

(A) The sensations described are known as paresthesias and could indicate several conditions. Paresthesia is the second most common complaint in DCS, coming just after musculoskeletal pain. It can and often is the only symptom. When these sensations occur on the skin, they can be the result of cutaneous DCS (aka "skin bends"), a condition that typically is benign and clears without treatment or residual, but may be an early warning signal with more serious features developing rapidly. It most commonly affects the torso and can range from a simple paresthesia to intensely itchy, mottled rashes.

The very transient pins-and-needles sensation variety is thought be the result of release of tiny gas bubbles from fast tissue compartments in or just beneath the skin. It is not unusual for those undergoing recompression treatment to experience such paresthesias upon "ascent." It is more common on the ears, hands and wrists, but can appear in the lower extremities.

Such sensations in the thigh also can be caused by spinal column problems such as a ruptured vertebral disc or sciatica. Where this is the case, the sensations often are accompanied by other signs or symptoms, such as pain or weakness in the affected limb. Here one would also look for a history of back injury or abnormality or of treatment for back or lower limb pain.

However, given: (1) dive profiles which are not at all suggestive of DCS; (2) paresthesia of the rear thighs as the only symptom; (3) occurrence only after diving in relatively cool water; and, (4) sensations that last for an extended period, high on the list of rule out diagnoses would be a wetsuit (or other topside or u/w garment), weight belt or other item that is excessively snug in the hip, groin or thigh area and is compressing a superficial cutaneous nerve.
Simple and fleeting paresthesias most commonly are the result of disruption of a nerve. For example, this, and not circulatory disruption as is commonly thought, is the cause of the pins-and-needles sensations and numbness that develop in an extremity from sleeping in an awkward position.

Eliminate this possibility first.

This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual and should not be construed as such.

Regards,
DocVikingo

Back to Doc Vikingo's Divers Resource Page
Contact Doc Vikingo

Back to Awoosh Main Directory