Raynaud's vs chilblains, acrocyanosis and other look-alikes
Raynaud's causes short episodes in which fingers or toes turn white, then blue, then red. Chilblains are itchy red or purple patches that appear hours after cold. Acrocyanosis is persistent, usually painless blue discoloration. Erythromelalgia is red, burning skin triggered by warmth. Cold urticaria causes itchy welts within minutes. Buerger's disease is a tobacco-linked artery disease that can mimic Raynaud's.
How do these conditions compare at a glance?
The timing and trigger are often the fastest way to tell these conditions apart. This table is a guide for conversations with your clinician, not a self-diagnosis tool.
| Condition | Main sign | Trigger and timing | Pain or itch |
|---|---|---|---|
| Raynaud's | White, blue, then red fingers or toes | Cold or stress; minutes to hours | Numbness, then tingling on rewarming |
| Chilblains | Red or purple patches, sometimes swollen | Appear a few hours after cold; clear in 2 to 3 weeks | Itching or burning |
| Acrocyanosis | Blue hands or feet that stay blue | Persistent, worse in cold | Usually painless |
| Erythromelalgia | Red, hot, swollen hands or feet | Warmth, exercise, tight shoes | Burning pain |
| Cold urticaria | Itchy welts on exposed skin | Within minutes of cold exposure | Itch, swelling |
| Buerger's disease | White then blue digits, sores | Linked to tobacco use | Pain in hands, feet or on walking |
What is the difference between Raynaud's and chilblains?
Raynaud's is a fast, reversible change in blood flow. The NHS describes skin turning white, possibly blue, then red as blood returns, over a few minutes to a few hours. Once warm, the skin looks normal again.
Chilblains are small areas of inflamed skin. The NHS says they are itchy patches that usually appear a few hours after cold exposure, turn red or purple, and go away on their own in 2 to 3 weeks. They form when deeper vessels stay narrow while surface vessels widen during rewarming, which is why the NHS advises against warming hands or feet on a radiator or under hot water. Both conditions can occur in the same person.
To lower the chance of chilblains, the NHS recommends warm, waterproof clothing, gloves and thick socks outdoors in cold weather, and advises avoiding smoking, caffeine and decongestants. It also says not to scratch or pick at affected skin. Anyone with diabetes should see a clinician about recurring chilblains, because slow-healing skin on the feet needs closer attention.
How is acrocyanosis different from Raynaud's?
Acrocyanosis causes bluish discoloration of the hands and feet. The Merck Manual notes that in acrocyanosis the blue color persists and is not easily reversed, it is typically painless, and skin changes such as thinning, shiny skin and ulcers do not occur. Pulses are normal and both sides are affected.
Raynaud's, by contrast, comes in episodes with a clear start and finish. Persistent blue color that appears on one side only, or comes with pain and sores, is not typical of simple acrocyanosis and needs medical review.
Is erythromelalgia the opposite of Raynaud's?
In many ways, yes. The NHS describes erythromelalgia as burning pain with redness and warm or hot skin, triggered by exercise, warm or tight clothing and shoes, hot weather, stress, alcohol or spicy food.
This matters for anyone looking at warming products. Heat makes erythromelalgia worse. The NHS suggests loose clothing and cooling with a fan or a cool, not cold, gel pack, and warns against ice or cold water because they can damage skin. A few people experience features of both conditions, so a clear diagnosis comes first.
What is cold urticaria?
Cold urticaria is an allergic-type skin reaction. Mayo Clinic describes itchy welts that appear within minutes of cold exposure and worsen as skin rewarms, along with swelling of the hands when holding cold objects or of the lips after cold drinks.
Unlike Raynaud's, it can be dangerous at whole-body scale. Mayo Clinic warns that swimming in cold water can trigger a severe reaction, including anaphylaxis. Anyone with welts after cold exposure should speak to a clinician before cold-water activities.
Could it be Buerger's disease or neuropathy?
Buerger's disease blocks blood vessels in the arms and legs. Mayo Clinic says nearly everyone who has it has smoked or used tobacco, and symptoms include fingers and toes that turn white then blue in the cold, tingling, pain and open sores. It is most common in men younger than 45. Stopping all tobacco use is essential.
Peripheral neuropathy can also make feet and hands feel cold, numb or tingly, but without the color episodes of Raynaud's. It often reflects nerve damage from diabetes and changes how you should use any heat source.
When should you see a clinician?
Talk to your clinician about any new or changing cold-related skin symptoms. Seek care promptly for these signs.
Sores, blisters or broken skin on fingers or toes, especially with diabetes.
Color that does not return to normal after warming, or darkening skin.
Symptoms on only one side of the body.
Chilblains that last longer than 2 to 3 weeks, keep returning, or show pus or fever.
Welts, lip swelling or faintness after cold exposure; call emergency services for trouble breathing.
How do chilblains differ from cold urticaria?
Both are skin reactions to cold, but they differ in timing and risk. DermNet describes chilblains as tender or itchy bumps on fingers, toes or other extremities that develop several hours after damp, non-freezing cold and last more than 24 hours. Cold urticaria, Mayo Clinic explains, causes itchy welts soon after a sudden drop in temperature or contact with cold water, and each bout may last about 2 hours.
The biggest difference is the whole-body risk. Cold urticaria can cause swelling of the tongue and throat or anaphylaxis, especially after swimming in cold water. Call emergency services for trouble breathing or a whole-body reaction, and talk to a clinician about any skin reaction to cold, even a mild one.
| Feature | Chilblains | Cold urticaria |
|---|---|---|
| Onset | Several hours after damp cold | Soon after cold exposure, worse as skin rewarms |
| Looks like | Red or purple swollen patches on fingers and toes | Itchy welts on exposed skin; swollen hands or lips |
| How long | More than 24 hours; often clears in 2 to 3 weeks | About 2 hours per bout |
| Serious risk | Skin breakdown, especially with diabetes | Throat swelling or anaphylaxis |
Key takeaways
Raynaud's is episodic: white, blue and red color changes that resolve after warming.
Chilblains are inflamed patches that appear hours after cold and clear over weeks.
Acrocyanosis is persistent, symmetric and usually painless blue discoloration.
Erythromelalgia is triggered by heat, so warming products can make it worse.
Cold urticaria and Buerger's disease need specific medical advice, not just warmer clothing.
Frequently asked questions
Can you have Raynaud's and chilblains at the same time?
Yes. Both involve how small blood vessels respond to cold, and they can occur in the same person. Gentle, gradual rewarming and avoiding direct high heat are sensible for both.
Why are my toes purple and itchy after being outside?
Purple, itchy patches that show up a few hours after cold are typical of chilblains. The NHS says they usually clear within 2 to 3 weeks. See a clinician if they persist, recur often, or you have diabetes.
Is acrocyanosis dangerous?
Primary acrocyanosis is usually harmless and painless. Blue color that is painful, one-sided or comes with sores may have another cause and should be checked.
Is it Raynaud's or poor circulation?
Raynaud's is a specific overreaction of healthy vessels, with episodes of color change. Blocked arteries, as in peripheral artery disease or Buerger's disease, cause more persistent problems such as leg pain on walking and slow-healing sores.
Should I use heat for erythromelalgia?
No. Warmth is a common trigger. The NHS suggests cooling with a fan or a cool gel pack, not ice or cold water.
What is the difference between acrocyanosis and Raynaud's?
Acrocyanosis is a persistent, painless blue discoloration of both hands or feet, while Raynaud's comes in episodes of white, blue and red color change that end once you warm up. DermNet notes that primary acrocyanosis is symmetrical and harmless and usually needs no treatment. Blue color on one side only, pain or sores is not typical of simple acrocyanosis and should be checked by a clinician.
What is the difference between Raynaud's and Buerger's disease?
Primary Raynaud's is an overreaction of otherwise healthy small vessels, while Buerger's disease inflames and blocks blood vessels in the arms and legs. Mayo Clinic says people with Buerger's almost always smoke or use tobacco, and it can cause painful open sores and gangrene; quitting all forms of tobacco is the only way to stop it. Sores on fingers or toes always need prompt medical care.
How can I tell chilblains from Raynaud's?
Timing is the clearest clue. Raynaud's color changes start during cold or stress and settle within minutes to hours once you warm up, while chilblains appear several hours after cold and stay for days to weeks as itchy, red or purple patches. The two can occur together, so describe the pattern to your clinician.
Is it chilblains or cold urticaria?
Chilblains appear hours after cold and last for days, while cold urticaria causes itchy welts within minutes that usually fade in about 2 hours. Cold urticaria can also cause lip or throat swelling, so seek emergency care for trouble breathing after cold exposure.
From HEATJAC
We design low-profile thermal garments: a heat-reflective vest and a thermal harness with pockets for warmers or cold packs. If you have reduced sensation or a health condition, check with your clinician before adding heat.
Choosing gear? Warmth that fits daily life with Raynaud's · Before you buy: a checklist for any warming garment
Related reading
Sources
Raynaud's, NHS
Chilblains, NHS
Acrocyanosis, Merck Manual Professional Edition
Erythromelalgia, NHS
Cold urticaria: Symptoms and causes, Mayo Clinic
Buerger disease: Symptoms and causes, Mayo Clinic
Chilblains, DermNet
Acrocyanosis, DermNet
About HEATJAC. HEATJAC is a thermal architecture company founded by an anesthesiologist. We design patented garment systems that capture, conduct and broaden warmth across the body, and we publish this knowledge hub because the science of staying warm should be public. HEATJAC products are not medical devices and are not intended to diagnose, treat, cure or prevent any disease.