CHILBLAINS

 

Chilblains, also called pernio or perniosis , are localized inflammatory lesions caused by continued exposure to cold above the freezing point. Dampness and wind that increase thermal conductivity and convection play a part. Absolute temperature is less important than the cooling of nonadapted tissue. The condition shows a genetic predisposition. It has been described most often in temperate regions, where winters are occasionally cold and damp. Chilblains are seen less often in very cold climates, where well-heated houses and warm clothing are available. Both acrocyanosis and chilblains appear to be more common in children, women, and persons with low body mass index. Spontaneous remission is common when spring arrives, and relapse is frequent during the following winters. However, chilblains do not always occur at the time of maximum cold.

Chilblains develop acutely as single or multiple, burning, erythematous, or purplish swellings. Patients may complain of itching, burning, or pain. In severe cases, blisters , pustules, and ulceration may occur. Characteristic locations include the proximal fingers and toes, plantar surfaces of the toes, heels, nose, and ears, but other sites like the calves and thighs can be affected . Lesions usually resolve in 1 to 3 weeks but may become chronic in elderly people with venous stasis. Tight garments such as gloves, stockings, and shoes are especially to be avoided in cases in which there is also peripheral vascular disease. A papular form of chilblains resembles erythema multiforme and occurs at all times of the year, usually in crops on the sides of the fingers, often superimposed on a background of acrocyanosis.

A peculiar clinical presentation may occur in young women riding horses for several hours daily during winter. Indurated red to violet tender plaques develop on the lateral calves and thighs . The condition is quite similar to the nodular perniotic lesions described in adolescent girls with erythrocyanosis. For prophylaxis, experienced riders usually wear baggy breeches that provide insulation and are not tight enough to compromise the circulation.

Perniotic lesions have been described in association with myeloproliferative disorders, probably as a consequence of blood flow changes, presence of cold agglutinins, and altered inflammatory response on cooling.

Idiopathic perniosis is characterized histologically by edema of the papillary dermis and by the presence of superficial and deep perivascular lymphocytic infiltrates. Necrotic keratinocytes and lymphocytic

vasculitis also have been reported. Thickening of blood vessel walls with intimal proliferation may lead to obliteration of the vascular lumen.

Chilblain lupus is a distinct disease and is similar to discoid lupus erythematosus. Lupus pernio is a variant of sarcoidosis  and is unrelated to cold injuries.

The unfamiliarity of physicians with chilblains sometimes gives rise to unnecessary hospital admissions with expensive laboratory and radiologic evaluations and, at times, hazardous therapy. The most important point in management is prophylaxis through the use of adequate, loose, insulating clothing and appropriate warm housing and workplace. Maintaining the blood circulation by avoiding immobility is also helpful. A short course of ultraviolet light therapy at the beginning of winter was a recommendation but has been challenged. Once chilblains occur, treatment is symptomatic with rest, warmth, and topical antipruritics. Calcium channel-inhibiting drugs may be effective in the treatment of severe recurrent perniosis, although they may cause headache and flushing that are troubling to some patients. In cases of crippling severity, thyrocalcitonin and hemodilution may be helpful