21,495views
00:00 / 00:00
of complete
of complete
2024
2023
2022
2021
Raynaud phenomenon p. 480
Raynaud phenomenon p. 480
Buerger disease p. 478
calcium channel blockers for p. 323
presentation p. 724
SLE p. 724
Raynaud phenomenon p. 479
Raynaud phenomenon is a phenomenon where there’s vasoconstriction of arteries near the skin that make a body part, often the fingers, turn white, then blue, and then red in response to a trigger like cold weather.
The phenomenon is named after Auguste Gabriel Maurice Raynaud, a French physician, who first described it.
To clear up some potentially confusing terminology, it’s called Raynaud disease or primary Raynaud phenomenon where the condition occurs alone and is not associated with any other disease, and it’s called Raynaud syndrome or secondary Raynaud phenomenon when it is associated with diseases like systemic lupus erythematosus or scleroderma.
Normally blood flows from large arteries into medium-sized or muscular arteries, and then into small arterioles which carry the blood to capillary beds.
All arterial vessels have three layers: from inside moving out, there’s the endothelium, then the media layer which contains smooth muscle, and finally the adventitia layer which has loose connective tissue and nerves.
Some nerve fibers in the skin function as thermoreceptors, which sense changes in temperature.
When stimulated, they cause the nerve to fire, sending signals up through the spinal cord to the hypothalamus, which is at the base of the brain.
The hypothalamus serves as the body’s thermostat because it coordinates the brain’s response to temperature changes.
The hypothalamus is what triggers the thought – “Hey, it’s pretty cold here. Maybe I should find a friendly llama to snuggle with for warmth.”
The hypothalamus also coordinates changes in the sympathetic and parasympathetic nervous system.
For example, normally, there’s a lot of heat energy in the blood, that gets lost to the environment.
When the sympathetic nervous system gets stimulated it causes contraction of smooth muscle that wraps around arterioles causing vasoconstriction and a reduction of blood flow to the skin.
Raynaud phenomenon is a condition in which due to cold temperatures or emotional stress, blood vessels in the fingers and toes constrict and restrict blood supply in affected areas. This can cause symptoms like numbness, tingling, brittle nails, and pain in the affected areas. In severe cases, fingers may turn white, reflecting ischemia, and then blue reflecting hypoxia, which is the low oxygen state that occurs after prolonged ischemia.
Raynaud phenomenon is common among pregnant women and people who work in jobs that cause lots of vibration, like using a jackhammer. It may also be a symptom of underlying conditions, such as systemic lupus erythematosus, scleroderma, vasculitides, or Takayasu's arteritis. Treatment includes avoiding triggers like cold temperatures, stress, smoking, and caffeine, and occasionally using a medication like a calcium channel blocker to help with vasodilation of the arteries. In severe cases, surgery may be necessary to cut the sympathetic nerve fibers supplying the affected areas and improve blood flow.
Copyright © 2024 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Cookies are used by this site.
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.