CB patients generally present in cold winter months. Immune-mediated vasculopathy and subsequent dermatological lesions are the most common symptoms of this disease. Acral tissues, i.e., toes, fingers, ears and nose, are most frequently affected. Rarely, lesions are observed on feet, heels or calves. Attention should be paid to the fact that patients presenting with equestrian perniosis show dermatological alterations on lateral thighs, buttocks and lumbar region.
Initially, patients may merely note a cyanotic or red discoloration of the skin. These lesions may be limited to very small areas of skin and correspond to macules or patches. In some cases, a slight elevation of the affected skin is palpable, rendering these lesions papules or plaques. Skin swelling may only occur upon rewarming of affected areas. If these parts of the skin are warmed again, lesions may become painful. Many patients also describe a burning sensation or claim pruritus.
Severe CB may be associated with formation of vesicles or bullae, either during cold exposure or warm up. Although ulceration may occur in any case, the latter are particularly sensitive to mechanical irritation and rupture easily if the patient scratches.
Chilblain lupus erythematosus may be the first symptom of cutaneous lupus erythematosus and thus, this condition is not restricted to patients formerly diagnosed with systemic lupus erythematosus. However, about 20% of those individuals presenting with chilblain lupus erythematosus will subsequently develop systemic lupus erythematosus . This type of CB is characterized by erythematous to violaceous plaques that appear upon exposure to cold.
The patient's medical history and additional anamnestic data should be considered when interpreting the results of clinical examination. An individual previously diagnosed with systemic lupus erythematosus may suffer from chilblain lupus erythematosus; a young woman who likes to ride horses wearing tight-fitting pants is a textbook example for a patient presenting with equestrian perniosis.
Further workup aims at confirming the tentative diagnosis of CB by ruling out differential diagnoses or identifying such a disorder as the underlying disease. In order to do so, laboratory analysis of blood samples and histopathological examination of tissue samples should be realized. By means of hemogram and blood biochemistry, hematological disorders and dysproteinemia may be identified. Detectable levels of auto-antibodies (e.g., antinuclear antibodies, antiphospholipid antibodies, rheumatoid factor) may reveal an underlying autoimmune disorder. Histopathological analysis of a skin biopsy obtained from a CB patient generally shows dermal edema/spongiosis, perieccrine and perivascular infiltration with inflammatory cells, mainly with lymphocytes, and necrotic cells in epidermal layers . Edematous changes of capillary walls may be observed, too. If vasculitis is diagnosed, it is of lymphocytic nature.
Warming up and avoidance of renewed exposure to cold temperatures are the mainstays of CB therapy. These measures increase peripheral circulation and usually, dermatological and vascular lesion spontaneously resolve after a few days, maximum a few weeks.
Recovery may be accelerated by administration of the calcium channel blocker nifedipine . A daily dose of 30 mg (per os, 10 mg tid) is often sufficient to induce adequate vasodilation, but may be increased if necessary. While mild side effects are to be expected, severe hypotension justifies cessation of nifedipine therapy. Therefore, blood pressure should be monitored if CB patients receive this drug. This also applies if amlodipine is used instead of nifedipine.
Alternatively, pentoxifylline may be used to improve peripheral circulation.
Prognosis is very good. Dermatological and vascular lesions generally remit as soon as temperatures rise. However, recurrence is frequent if feet, hands and face are again exposed to cold, damp weather.
CB results from prolonged exposure to humid cold. However, such weather conditions cause perniosis only in a small share of the general population, presumably in predisposed individuals. In this context, various pathologies have been proposed to contribute to CB, but the possibility that these diseases and CB are triggered by the same factors rather than being mutually dependent should be considered.
Raynaud phenomenon is frequently associated with CB. A causative relation could not yet be shown.
In general, patients with a low body mass index are more susceptible to cold and are thus at higher risks of developing CB. Any pathological reduction of body fat may thus be considered a risk factor for this disease.
Of note, genetic predisposition has been shown for certain subtypes of CB, mainly for chilblain lupus erythematosus, and is likely to play a role in other forms of the disease.
CB is presumed to be highly underdiagnosed. Thus, overall incidence and prevalence rates cannot be provided.
Racial predilection has not been reported. Women are affected more than twice as often as men .
With regards to geographical regions, CB may probably be diagnosed in any country whose climate is marked by periods of cold, damp weather. Perniosis usually resolves as soon as temperatures rise again and very few cases will be seen in summer.
In order to maintain an adequate body temperature, peripheral vessels constrict when the skin is exposed to cold (thereby, an excessive loss of body heat is avoided) and dilate in warm conditions (to facilitate heat release). In CB patients, cold-induced vasoconstriction either persists for prolonged periods of time or reduces blood flow to such an extent that the surrounding tissues suffer from hypoxia . This phenomenon corresponds to a disturbed thermoregulatory reflex. As has been described above, the etiology behind it is not well understood.
According to current knowledge, the inflammatory reaction observed in histopathological samples is secondary to vasoconstriction and hypoxia. ATP-dependent ion pumps fail under such conditions and cytotoxic edema develops rapidly. Furthermore, hypoxia may induce apoptosis as well as necrosis in affected skin layers and the latter may cause local inflammation and exacerbate skin edema. In fact, necrotic cells are frequently observed in samples obtained from CB patients and dermal edema, histologically referred to as spongiosis, may be of importance to distinguish CB from systemic lupus erythematosus . Additionally, lymphocytic infiltrates are typical for CB and are mainly observed in close proximity to skin glands.
In general, acral tissues should be protected against cold and humidity by wearing of adequate clothing. Warm socks and shoes help to prevent CB as much as gloves, scarf or buff. Lose-fitting clothes provide an isolating layer of air and are thus better suited to keep warm than tight outfits.
If exposure to cold can't be avoided completely, time intervals should be kept as short as possible. Gradual rewarming is preferred over exposure to heat.
Smoking may aggravate CB and should thus be avoided.
In order to avoid equestrian perniosis, horses should preferentially be ridden in somewhat warmer conditions. Because the animals need to be moved in winter, too, more frequent but shorter horse rides are recommended. Also, tight-fitting riding clothes are inappropriate for people susceptible for equestrian perniosis.
Chilblain (CB) is an uncommon inflammatory disease frequently also referred to as perniosis or pernio. Patients suffering from CB develop localized capillary vasculitis upon prolonged exposure to cold, damp weather conditions. Toes, fingers, ears and nose are most susceptible to cold-induced tissue damage and consequently CB manifests in dermatological lesions generally restricted to these parts of the body .
While a considerable part of CB cases is deemed idiopathic, underlying diseases like cyroglobulinemia, autoimmune or connective tissue disorders may predispose a patient to CB. Several other diseases have been associated with CB, but their causative relation is not always clear. For instance, about one out of five CB patients also shows Raynaud phenomenon, but it is not known whether both pathologies are triggered by the same etiological factors and which conditions determine if an individual develops CB, Raynaud phenomenon or both.
Deep red or purple lesions of acral tissues are characteristic symptoms of CB. A tingling sensation or pain may be noted as the affected parts of the body warm up. In severe cases, blisters may form and rupture upon mechanical irritation.
Histopathologic analysis of tissue samples reveals that CB is indeed an inflammatory disorder: Dermal edema and infiltration with lymphocytes is a characteristic, yet non-specific finding . Necrotic keratinocytes may be observed in epidermal layers. Histopathologic examination may be required to rule out differential diagnoses like vasculitis due to other causes (e.g., immune-mediated Henoch-Schönlein purpura or Churg-Strauss syndrome; leukocytoclastic, urticarial vasculitis; granulomatous vasculitis), embolism or systemic lupus erythematosus .
In most cases, CB resolves spontaneously if the patient warms up accordingly. Prevention is mainly based on avoidance of prolonged exposure to cold, damp weather without wearing proper clothes.
Chilblains (CB) is an inflammatory disorder characterized by vascular and dermatological lesions of toes, fingers, ears and nose upon prolonged exposure to cold, damp weather.
If the human skin is exposed to warmth, blood vessels dilate to facilitate heat release. On the other hand, exposure to cold causes vasoconstriction and assures that body heat is maintained. In CB, vasoconstriction persists for prolonged periods of time and consequently, surrounding tissues are not adequately supplied with oxygen. This interferes with cellular metabolism, causes necrotic cell death and dermal edema.
Presumably, part of the population is predisposed for this exaggerated response of the body to cold. Although knowledge gaps remain, there seems to be an association between hematological diseases, autoimmune disorders and CB.
As has been indicated above, dermatological lesions are generally restricted to toes, fingers, ears and nose. A particular subtype of CB is mainly observed in young women who ride horses in cold weather and here, skin alterations are observed on outer thighs, buttocks and in the lumbar region.
Patients may initially not a reddish-blue discoloration of the affected skin. As soon as these areas of the body are warmed up, sensations like burning, itching and pain may be perceived. The skin may swell. In rare cases, blisters may form.
Only the dermatological consequences of the underlying vasculopathy may be assessed during physical examination.
Thus, it is necessary to obtain a tissue sample and analyze it histopathologically if symptoms persist for more than a few weeks. Such an analysis will reveal inflammatory infiltrates within the dermis, dermal edema and necrosis of epidermal cells. These findings are important to rule out differential diagnoses.
Also, blood samples may need to be analyzed. Hemogram and blood biochemistry may indicate hematological diseases like cold agglutinin disease, dysproteinemia and leukemia as well as autoimmune disorders such as systemic lupus erythematosus or rheumatoid arthritis.
In most cases, the condition is self-limiting. After a few weeks or as soon as temperatures rise, symptoms subside. However, recurrence during the next cold season is likely.
Recovery may be accelerated by administration of nifedipine, a drug causing vasodilation by inhibiting calcium channels. Also, topical application of corticosteroids has been shown to effectively reduce symptoms, mainly pruritus. Scratching predisposes for secondary bacterial infection and thus, reduction of itching also serves as a preventive measure against wound infection.