The short version
- Chilblains are itchy or burning red to purple patches on fingers and toes that appear a few hours after damp cold, not freezing cold[1][2].
- They usually clear on their own in 2 to 3 weeks; warm the skin slowly and never on a radiator or under hot water[1].
- At Mayo Clinic, warming, drying and stopping smoking gave a complete response in 23 of 28 patients (82%) with follow-up[3].
- Nifedipine is often prescribed, but a 2016 randomized trial in 32 patients found it no better than placebo[4].
Chilblains, trench foot or frostbite?
All three are cold injuries, and a winter crew can see all three in one season. The trigger and the timing tell them apart.
| Injury | Trigger | What you see |
|---|---|---|
| Chilblains (pernio) | Damp cold above freezing[2] | Itchy, burning red or purple patches hours later, lasting more than 24 hours[2] |
| Trench foot | Wet cold above freezing[9] | Nerve and blood vessel injury of the feet; needs moisture[9] |
| Frostbite | Below 0 °C[10] | Frozen tissue that needs rapid rewarming[10] |
Symptoms, and who gets chilblains
| Source | Finding |
|---|---|
| Mayo Clinic, 104 patients[3] | 79% women, mean age 38.3; toes in 82%, fingers in 30%; 4% had connective tissue disease and 3% a blood cancer |
| Military hospital, Leh, India[6] | 108 cases in one winter season, only one in a local resident; 42.1% also had heavy sweating and 19.4% smoked |
| DermNet risk list[2] | Smoking, low body weight and outdoor work, naming fishermen and farmers; peak in late winter and early spring |
| Cold chamber study, 2026[7] | People with a history of chilblains had lower skin blood flow in the cold and signs of low tissue oxygen |
Severe chilblains can blister or ulcerate[2]. Chilblains are unusual in older adults, and DermNet advises looking for an underlying cause in them[2].
Chilblains treatment: what the evidence supports
| Treatment | Evidence |
|---|---|
| Warming, drying, no smoking | Complete response in 82% of followed Mayo patients[3] |
| Steroid cream (betamethasone valerate 0.1%) | May relieve itch, twice daily[2] |
| Nifedipine, by prescription | Faster healing in a 1989 trial at 20 to 60 mg a day[5]; no benefit over placebo in a 2016 trial, with more ankle swelling[4] |
| Topical nitroglycerin | Listed as an option; reviews note there are no high-quality trials for any chilblain drug[2][8] |
What to do on board
- Get dry first. Swap wet gloves and socks for dry ones[1].
- Rewarm slowly at room temperature; no radiator, engine-room pipe or hot water[1].
- Do not scratch; a soothing lotion or the chest’s steroid cream can ease the itch[1][2].
- Cover broken skin with a loose dry dressing and watch for pus.
- Cut the vasoconstrictors: smoking, caffeine and decongestant tablets all reduce blood flow to fingers and toes[1].
When chilblains need a doctor
Get medical advice if the skin is not better after 2 to 3 weeks, there is pus, a high temperature or shivering, chilblains keep coming back, or the crew member has diabetes[1]. Blisters or ulcers need a physician’s eye[2]; at sea that means radio medical advice, logged in the medical log.
Prevention for winter crews
DermNet’s prevention list fits a deck crew well: warm dry clothing for hands, feet and ears, vigorous exercise to keep warm, warm dry living spaces and no smoking[2]. Spare dry gloves at the wheelhouse door and a drying rack for socks do more than any cream. For the rest of the cold-weather plan, see cold water immersion survival and Alaska fishing vessel medical compliance.
Cold injuries are predictable on winter fleets, which makes them a planning problem before they are a medical one. Discovery Health MD covers both sides: maritime medical consulting for the cold-injury section of your medical plan, and ship medical chest management for the steroid creams, dressings and thermometers it relies on. Get a physician to review your winter cold-injury plan.
Common questions
What are chilblains?
Small itchy or burning patches on the skin, usually fingers and toes, that appear after cold exposure[1].
How long do chilblains last?
Usually 2 to 3 weeks; DermNet gives 1 to 3 weeks, with possible recurrences[1][2].
What is the best treatment for chilblains?
Warming, drying and stopping smoking worked fully in 82% of followed Mayo Clinic patients[3].
Should you put chilblains in hot water?
No. Warm the skin slowly and avoid radiators and hot water[1].
Does nifedipine work for chilblains?
The evidence is mixed: a 1989 trial found benefit, a 2016 randomized trial found none[5][4].
Are chilblains the same as frostbite?
No. Chilblains follow damp cold above freezing, while frostbite needs temperatures below 0 °C[2][10].
Who is at risk of chilblains?
Smokers, people with low body weight and outdoor workers such as fishermen and farmers[2].
