1.3.2 Pernio

Grading & Level of Importance: A

Review:

2026

W. Burgdorf, Munich; D. Trokoudes, J. McGrath, A. Salam, London
Revised by H. Gollnick, Magdeburg

Overview:

ICD-11
Synonyms
Epidemiology
Definition
Aetiology & Pathogenesis
Signs & Symptoms
Localisation
Classification
Laboratory & other workups
Dermatopathology
Course
Complications
Diagnosis
Differential Diagnosis
Prevention & Therapy
Special

ICD-11

NF03.0

Synonyms

Dermatitis congelatio escharotica; Chilblains; perniosis

Epidemiology

Congelatio quite frequent in winter sport activities, mountain tracking; perniones mostly appear in spring and autumn around 0ºC degree. Often in adolescents with acrocyanosis (horse riding, long time cycling, inappropriate shoes, wet socks).

Pernio mostly appear in spring and autumn around 0°C, acold, damp conditions. In adolescents with acrocyanosis (horse riding, cycling for long periods, inappropriate shoes, wet socks) acral areas are affected.

The so called secondary pernio is associated with other conditions such as lupus erythematodes (SLE /-chilblain CHLE). Most pernio cases are idiopathic. Any cases of pernio should prompt the clinician to check for some secondary conditions known to trigger pernio.

Congelatio appears in the skin and deeper tissue mostly during winter sport activities, mountaineering, but also to be observed in those sleeping outdoors.

Definition

Congelatio: 1st to 3rd degree with maximum of irreversible necrosis or death. Perniones: Cold-induced blue-red indurated papules or nodules, usually on legs or feet. F > M.

Aetiology & Pathogenesis

Congelatio dependent on temperature grade and exposure time. Persistent exposure to cold, damp conditions predisposes to development of pernio over days to weeks.

Signs & Symptoms

In congelatio in grade 1 erythematous lesions, in grade 2 bullous lesions and grade 3 necrosis with irreversible sequelae. In perniones blue-red oedematous papules or nodules, sometimes quite tender or painful.

grade 1, erythematous lesions develop first, followed by,
grade 2, bullous lesions, and,
grade 3, necrosis with irreversible sequelae. Large body areas with long exposure time may lead to death. In perniones, blue-red oedematous papules or nodules develop, sometimes they are quite tender or even painful. Those appear at temperatures from 0°C to 4°C.

Localisation

Typically occur at acral sites and in areas which are easily cooled (especially the shins, fingers, toes and other thighs in equestrians). Dampness is also important and some professions are at increased risk, such as butchers and farmers. In congelatio depending if local or full body cold exposure.

Classification

Congelatio: Grade 1 – 3.

Grade I: dermatitis congelationis erythematosa: ischemia, narrowing of capillaries, pale skin. After rewarming, a burning erythema develops. Almost always, a restitutio ad integrum is the course of grade I.

Grade II: dermatitis congelation bullosa: after rewarming a subepidermal bullous eruption occurs, sometimes hemorrhagic.

Grade III: Dermatitis congelatio escharotica: the colour of the skin changes from pale to blue to black; by palpation it is tense or hard and lacking sensitivity. If localized, a demarcation later appears and rejection of necrotic tissue.

Laboratory & other workups

None.

Dermatopathology

Congelatio: depending of degree vessel narrowing, blistering, apoptosis and necrosis.

Perniones: severe courses show blistering, edema, hyperemic vessels and lymphocytic vasculitis.

Pernio: in severe cases, blistering, edema, hyperemic vessels with heavy inflammatory cell infiltrate lymphocytic vasculitis and frequent involvement of the eccrine glands.

Congelatio: depending on the different degrees one observes vessel narrowing, blistering, apoptosis and necrosis.

Course

Congelatio: depending on length of injury in part reversible or irreversible.

Perniones: Recurrent, more common in spring and autumn (cool, moist climatic conditions).

Pernio: they are recurrent, more common in spring and autumn (cool, moist climatic conditions).

Congelatio: depending on the length of injury, it may be in part reversible or irreversible. Long-term extensive body surface area involvement leads to death.

Complications

Congelatio: longterm downcooling death.

Perniones: Rarely ulceration.

Diagnosis

History, localization, clinical features.

Differential Diagnosis

Lupus pernio (sarcoidosis), chilblain lupus (lupus erythematosus).

Lupus pernio (sarcoidosis), chilblain lupus (lupus erythematosus). Diabetic and/or atherosclerotic necrosis or blue acral discolouration.

Prevention & Therapy

Congelatio: slow warming up of central temperature, no direct warming of involved lesions. Hyperbaric oxygenation to avoid amputation, prostaglandin infusions.
Perniones: warm, water-resistant protective clothing, topical or oral vasodilators (e.g. calcium channel blockers).

Perniones: warming up of body and local temperature at exposure site. Water-resistant protective clothing is recommended. Topical or systemic vasodilators (e.g. calcium channel blockers) can be used.

Congelatio: slow warming up of the central body temperature, no direct warming of involved lesions should be done. Hyperbaric oxygenation to avoid amputation in severe cases in special centers and immediate prostaglandin infusions should be given.