Dermatology & Internal Medicine & Family Medicine
Frostbite | Clinique Omicron Quebec
Chilblains—known as pernio (from the Latin *pernio*) in medical literature—are non-freezing inflammatory skin lesions resulting from an abnormal reaction of the skin’s microcirculation to repeated exposure to damp cold and sudden temperature changes, without the tissues actually freezing. They are thus distinct from frostbite, which involves actual tissue freezing with the formation of intracellular crystals. The pathophysiology is based on prolonged arteriolar vasospasm in response to cold, followed by excessive reactive vasodilation upon rewarming—leading to increased capillary permeability, localized edema, and a characteristic perivascular inflammatory reaction. Frostbite typically occurs during prolonged exposure to cool, damp temperatures (0 to 15 °C)—it is more common than is generally believed in regions with a temperate-cold climate such as Quebec, where humidity exacerbates the perception and biological effects of cold even at moderate temperatures. Young, slender women with an ectomorphic body type, people with Raynaud’s phenomenon or increased vasomotor sensitivity, children, and the elderly are the most vulnerable. Frostbite primarily affects the most exposed and least well-vascularized extremities: fingers, toes, ears, nose, cheeks, and thighs (particularly the back of the thighs in horseback riders and winter sports enthusiasts wearing jeans—which do not protect against damp cold). In the vast majority of cases, frostbite is idiopathic and benign, resolving spontaneously within a few weeks once exposure ceases. However, its seasonal recurrence, functional impact (pain, intense itching), and possible association with underlying systemic diseases (systemic lupus erythematosus, cryoglobulinemia, antiphospholipid syndrome) warrant medical evaluation, particularly in atypical, severe, or persistent cases that extend beyond the cold season.
Clinical presentation, forms, and risk factors
- Typical clinical presentation: lesions appearing 12 to 24 hours after exposure to damp cold - erythematous to purplish papules, plaques or nodules, 1 to 3 cm in diameter, edematous, with ill-defined edges, sometimes slightly raised; location: fingers and toes (dorsal surface - 1st and 5th rays often spared) + ears + nose + cheeks + heels + posterior surface of thighs; symptoms : intense pruritus + burning sensation + pain on palpation + characteristic aggravation on warming (return to a warm place → onset of disabling itching); spontaneous resolution in 1 to 3 weeks with the end of cold exposure; severe forms: bullae + ulcerations + scabs - slower healing (4 to 6 weeks) with risk of residual pigmented scars
- Specific clinical forms: perniosis of the thighs (pernio equestre): purplish patches on posterior and lateral thighs - women wearing non-insulating clothing in winter (damp jeans, leggings) - young women + horse riders + cross-country skiers; perniosis associated with anorexia nervosa: defective skin microcirculation + absence of insulating fat mass + malnutrition → severe, recurrent frostbite at mild temperatures; perniosis chilblain lupus : association with cutaneous lupus erythematosus - chronic, induced, purplish lesions of fingers + ears + nose + in a woman between 30 and 50 years of age - biopsy essential (deep perivascular lymphocytic infiltrate) + ANA, anti-dsDNA, complement workup; COVID-19 frostbite (COVID toes): cutaneous manifestation described in 2020 - erythematoviolent lesions of toes and fingers in young patients with asymptomatic or mild COVID picture - mechanism debated (micro-thrombosis + viral vasculitis) - spontaneous resolution in a few weeks
- Risk factors and associated diseases: constitutional factors: low BMI + ectomorphic constitution + young woman + primary or secondary Raynaud's phenomenon + constitutional acrocyanosis; systemic diseases to be excluded in severe or atypical forms: systemic lupus erythematosus (SLE - ANA + anti-dsDNA + complement) + cryoglobulinemia (chronic hepatitis C - serum cryoglobulins) + antiphospholipid syndrome (IgG/IgM anticardiolipin antibodies + anticoagulant lupus) + monoclonal gammopathy + chronic lymphocytic leukemia (CLL) + polycythemia vera + dysproteinemias; vasoconstrictive drugs that promote: beta-blockers (propranolol, atenolol) + triptans + ergotamine + amphetamines + cocaine
- Differential diagnosis : frostbite — frozen tissue, white, numb, blistered after warming — temperatures <0 °C — emergency; Raynaud's syndrome — paroxysmal episodes of pallor + cyanosis + reactive erythema (tricolor triad) in the extremities with cold exposure — no permanent skin lesions between attacks; lupus pernio (sarcoidosis) — purplish nodules on the nose + cheeks + ears — biopsy: epithelioid granulomas — not to be confused with idiopathic chilblains; leukocytoclastic vasculitis — vascular purpura + characteristic biopsy; erythema multiforme — bilateral targetoid lesions + often mucosal involvement — infectious (HSV) or medication trigger
Treatment and prevention
| Treatment | Mechanism, technique and procedures | Efficiency, duration, and precautions |
|---|---|---|
| General measures warming First-line treatment — essential and immediate |
Removal from cold exposure: Immediately stop all exposure to cold and wet — return to a heated environment, change wet clothing, and gently dry the affected area. Passive and gradual warming: Allow lesions to warm up at room temperature. Never rub affected areas vigorously (risk of trauma to fragile skin). Never apply a direct heat source (hot water bottle, hot water, open fire) to numb, insensitive, or frostbitten skin (risk of heat burn on skin with altered sensitivity). Mechanical protection: Non-compressive, non-adhesive dressings (Mepilex, Adaptic) on ulcerated or blistered lesions. Elevate lower limbs if there is associated edema. Maintain general body heat: Warm, sugary drinks and sufficient food intake (thermogenesis). Smoking cessation: Nicotine is a potent peripheral vasoconstrictor, worsening microcirculation and chilblains. Cessation is essential in recurrent cases. | Gradual warming to room temperature is the most important and safest measure—warming too quickly with direct heat can worsen pain and injury by causing sudden reactive vasodilation on insensitive skin; spontaneous resolution is the rule in simple chilblains within 1 to 3 weeks with cessation of exposure—inform the patient that itching temporarily worsens during warming (normal reaction) before subsiding; in patients with associated Raynaud's phenomenon: learning thermal protection techniques + gradual warming at the first signs of vasospasm (before lesions appear); for patients who must be exposed to cold professionally (outdoor workers): merino wool socks + silk liners + waterproof gloves + insulated footwear + layered clothing (layering) + avoid cotton, which retains moisture |
| Corticosteroids and topical treatments Reduction of local inflammation and itching |
Topical corticosteroids (dermal corticosteroids): Apply 1 to 2 times daily to active erythematous lesions (papules, plaques, pruritic nodules) during the inflammatory phase — moderate- to high-potency class: triamcinolone 0.1% 1–3 times daily (Kenalog cream) or mometasone 0.1% 1–3 times daily (Elocom cream) × 1 time daily × 7 to 14 days on the limbs + hydrocortisone 1% 1–3 times daily or desonide 0.05% 1–3 times daily on the face and sensitive areas (nose, ears); oral antihistamines (H1 blockers): hydroxyzine (Atarax) 25–50 mg at bedtime (sedative + antipruritic effect) or cetirizine (Reactine) 10 mg × 1/day during the pruritic phase — these do not treat the cause but improve comfort, particularly sleep quality; local care for ulcerated lesions: cleansing with saline solution + non-adhesive ointment dressing (Vaseline gauze, Adaptic) changed daily — no harsh antiseptics (alcohol, concentrated hydrogen peroxide) on ulcerations — ointment gauze or Mepitel if ulcerations are extensive; emollient moisturizing cream: apply after topical corticosteroids to maintain the skin barrier (Cerave, Glaxal Base, petroleum jelly) — improves tolerance and healing | Dermocorticoids reduce local inflammation and itching but do not affect the underlying vasomotor mechanism. They are useful for comfort but do not significantly shorten the healing time of chilblains. Do not use dermocorticoids on active ulcerations or secondarily infected lesions. Limit application to 10 to 14 consecutive days to avoid skin atrophy, especially on the face and thin areas (fingers, ears). Sedating antihistamines (e.g., hydroxyzine) are particularly useful if nocturnal itching disrupts sleep; use them sporadically for short courses, not long-term. |
| Nifedipine and vasodilators Recurrent or severe forms — calcium channel blocker |
Extended-release nifedipine (Adalat): L-type calcium channel blocker — potent peripheral arteriolar vasodilator — reduces cold-induced vasospasm responsible for chilblains; dosage: extended-release nifedipine 30 mg once daily (or 20 mg twice daily) orally — start at 10 mg/day and increase gradually if hemodynamically tolerated — continue throughout the cold season or until lesions resolve; indications: recurrent chilblains season after season + severe chilblains with ulcerations + debilitating chilblains resistant to local measures + associated secondary Raynaud's phenomenon; alternative: extended-release diltiazem 60–120 mg once daily (non-dihydropyridine calcium channel blocker) if nifedipine is poorly tolerated; amlodipine (Norvasc) 5 mg once daily: another option (better tolerated than immediate-release nifedipine — less abrupt hypotensive effect); pentoxifylline 400 mg three times daily: rheologic agent (improves red blood cell deformability + reduces blood viscosity) — complementary option in resistant forms; doxycycline 100 mg twice daily for 3 weeks: limited data but some series suggest a benefit (anti-inflammatory effect + possible effect on microcirculation) | Nifedipine is the most well-documented pharmacological agent for recurrent chilblains (Dowd 1986 Br J Dermatol - reduction in lesion severity and frequency with nifedipine vs. placebo); side effects of nifedipine: flushing + headaches + orthostatic hypotension (especially at the start of treatment) + ankle edema + reflex tachycardia - start with a low dose and increase gradually; contraindications to nifedipine: pre-existing arterial hypotension + severe heart failure + pregnancy (1st and 3rd trimesters - teratogenicity and effects on fetal circulation) + interaction with grapefruit juice (CYP3A4 inhibition → increased toxicity); nifedipine is not covered by RAMQ for chilblains (off-label indication) - covered for arterial hypertension and angina. |
| Systemic disease assessment Atypical, severe, or persistent forms |
Systemic assessment indication: Frostbite persisting beyond the cold season (> April–May in Quebec) + severe form with deep ulcerations + strict bilaterality + age >50 years without usual risk factors + indurated lesions + unusual involvement (trunk, thighs) + associated systemic signs (fatigue, arthralgia, alopecia, photosensitivity); recommended assessment: CBC + ESR + CRP + ANA (antinuclear antibodies) + anti-dsDNA (lupus-specific) + complement C3 and C4 + antiphospholipid antibodies (lupus anticoagulant + anticardiolipin IgG/IgM + anti-beta2-GP1) + serum cryoglobulins (tubes kept at 37°C until the lab — special collection) + serum protein electrophoresis (SPEP) + immunoelectrophoresis + anti-Ro (SSA) and anti-La (SSB) antibodies (Sjögren's + neonatal lupus) + TSH (hypothyroidism favoring vasomotor disorders) + HCV serology (mixed cryoglobulinemia); skin biopsy: if lupus chilblain or atypical form is suspected — histology: deep perivascular lymphocytic infiltrate + PAS deposits + DIF (direct immunofluorescence) | The vast majority of chilblains (80–90%) are idiopathic in young people with constitutional predisposing factors—systemic evaluation is reserved for atypical or severe cases; lupus chilblains (cutaneous lupus pernio) is a distinct entity—chilblains are often the first manifestation of lupus and may precede diagnosis by several years—skin biopsy is essential + comprehensive autoimmune workup; Type II mixed cryoglobulinemia (associated with HCV) may present with chilblains + palpable purpura + arthralgia + peripheral neuropathy → routine HCV screening in this clinical picture; Low-titer ANA positivity (<1/160) is relatively common in the general population and in idiopathic chilblains without pathological significance—only clear positivity (>1/320) plus a compatible clinical presentation warrants a comprehensive rheumatological evaluation |
| Prevention of seasonal relapses Thermal protection - lifestyle |
Optimal thermal protection of extremities: waterproof gloves + insulating gloves (merino wool or Gore-Tex gloves) — immediately change wet gloves + merino wool socks (avoid cotton which retains moisture) + well-fitting insulated waterproof shoes (do not overtighten — risk of vascular compression) + hat covering the ears + neck gaiter + thermal underwear covering the thighs (thermal leggings); layering strategy: base layer of merino wool or polypropylene (wicks away sweat) + insulating layer (wool, down, fleece) + waterproof, windproof outer layer; avoid constrictive clothing (too tight socks, rings) which compromise distal microcirculation; maintain good hydration and nutrition: central hypothermia promotes peripheral vasoconstriction — maintain sufficient food intake and adequate hydration in cold environments; nifedipine SR for seasonal prevention: start at the beginning of autumn (October) in patients with severe recurrent chilblains — continue until the end of the risk period (April); stop vasoconstrictor medications if possible (beta-blockers → replace with another antihypertensive if absolute non-cardiac indication) | Prevention is by far the most effective strategy—rigorous thermal protection of the extremities can prevent almost all recurrences in patients with a constitutional risk; informing patients that wet denim jeans are a major risk factor for thigh chilblains in Quebec in the fall and spring—education on appropriate clothing is an important primary prevention measure; nifedipine for seasonal prevention (started before cold exposure) is more effective than its purely curative use (when lesions have already formed)—it is preferable to start it in September-October in patients with documented annual recurrences; hand warmers (chemical pads) can be useful as a supplement but do not replace insulating gloves—be careful of the risk of burns if placed directly on the skin of a person with reduced sensitivity. |
ℹ️
Frostnip vs. Frostbite — An Essential Clinical Distinction: chilblains (perniosis) are often confused with frostbite, but these two conditions are fundamentally different. Chilblains occur in cool, non-freezing temperatures (0 to 15 °C) with humidity, without tissue crystallization — the tissues are not frozen — and resolve completely within weeks. Frostbite involves actual freezing of the tissue (temperatures (<0 °C) with the formation of intracellular crystals, cell necrosis, and a risk of amputation if severe — they constitute a medical and surgical emergency. Clinically, frostbite presents with cold, white, waxy, hard, anesthetized skin, followed by hemorrhagic blisters and black necrosis after rewarming. Management is radically different: for frostbite, rapid rewarming in hot water (37–42 °C), systemic ibuprofen, anticoagulation, and sometimes intravenous thrombolysis or iloprost in severe cases at specialized centers.
Signs requiring prompt medical attention
See your doctor promptly if: Lesions that do not heal after 3 to 4 weeks despite cessation of exposure and local treatment, or persistent lesions outside the cold season → assessment of systemic disease (lupus, cryoglobulinemia) essential.
Deep ulcerations + skin superinfection (pus, odor, perilesional cellulitis, fever) → oral antibiotic therapy and specialized local care as a matter of urgency.
Severe chilblains with signs of digital ischemia (fingers or toes completely white, cold, numb, painful) → urgent evaluation to exclude frostbite, arteriopathy or secondary severe Raynaud's syndrome.
Consult at Clinique Omicron
Clinique Omicron doctors evaluate and treat recurrent or severe chilblains—including clinical diagnosis, local care, nifedipine prescription if indicated, systemic disease workup for atypical forms, and referrals to dermatology or rheumatology if necessary. Consultations are available at our Quebec service points and via telemedicine for seasonal follow-up. To book an appointment, visit cliniqueomicron.ca.
The content of this page is for informational purposes only and does not substitute for the advice of a qualified healthcare professional. Persistent frostbite or frostbite associated with systemic signs should be medically evaluated to rule out an underlying condition.
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