Dr. Paul Auerbach is the world's leading outdoor health expert. His blog offers tips on outdoor safety and advice on how to handle wilderness emergencies.See all posts »
Raynaud's Phenomenon and Altitude
RP is constriction of tiny blood vessels in the fingers and/or toes after exposure to cold or an emotionally stressful situation. The initial appearance is one of severely blanched (whitened) or bluish skin, often with a sharp “cut-off” margin in the midportion of the digit(s). This is caused by decreased circulation. The episode ends with vigorous reflow of blood into the digit, which causes it to become warm and reddened. This phenomenon is different and much more pronounced than the normal mottling or diffuse and persistent discoloration sometimes seen in hands and feet exposed to cold. RP is usually symmetrical, involving both hands or both feet, and is usually apparent in sufferers by the age of 40 years. Because RP can be associated with a number of underlying diseases or anatomic abnormalities, a first-time sufferer should seek medical evaluation. Prevention in the outdoors involves primarily protecting the hands and feet and keeping them warm, avoiding drugs that cause blood vessel constriction, and prohibiting tobacco use. Many drugs have been recommended at one time or another to treat RP, but at the currrent time the calcium-channel blockers (such as nifedipine) and drugs that block the sympathetic nervous system (which causes blood vessels to constrict) are most in favor as therapies for use outside of the hospital. Blood vessel dilators, such as nitroglycerin or niacin, have not been proven effective.
Volunteers with RP were recruited to complete an online anonymous survey, which addressed aspects of their RP and mountaineering activities. Eighty-nine percent of respondents engaged in winter sports, but only 22% reported changing their mountain activities because of Raynaud’s phenomenon. Only 12% used prophylactic medications to attempt to prevent or mitigate their RP. Fifteen percent of respondents reported an episode of frostbite following a RP attack at high altitude.
The conclusions were that motivated individuals with primary RP, employing various prevention and treatment strategies, can engage in different activities, including winter sports, at altitudes above 2440 meters. Frostbite may be common in this population at high altitude, and care must be taken to prevent its recurrence.
image courtesy of www.clevelandclinic.org
Recent Blog Posts
Jul 01, 2013
In Advance of a Wildfire
Feb 11, 2013
Topical Ivermectin Lotion for Treating Head Lice
Feb 04, 2013
Public Health Interventions and Snowmobile Fatality Rates