Pernio in pediatrics.

Pernio, or chilblains, is a localized inflammatory lesion of the skin resulting from an abnormal response to cold. Five cases were seen among adolescent female patients who presented to our rheumatology service in a pediatric tertiary care center in the winter of 2003 to 2004. All 5 patients were thin (BMI of <25th percentile) and had either toes or fingers that were affected. For each, laboratory evaluation results were unremarkable, including negative antinuclear antibody profile results. Symptomatic treatment, with or without medication, was recommended. Pernio most commonly occurs among young women but may occur among older individuals or among children. Because pernio develops among susceptible individuals who are exposed to nonfreezing cold, the lesions usually begin in the fall or winter and disappear in the spring or early summer. Acute pernio may develop 12 to 24 hours after exposure to the cold. Single or multiple erythematous, purplish, edematous lesions appear, accompanied by intense pain, itching, or burning. Chronic pernio occurs with repeated exposure to the cold and the persistence of lesions. In an acute exacerbation, the major differential diagnosis alternative would be Raynaud's phenomenon, which consists of sharply demarcated cutaneous pallor and cyanosis, followed by erythema, of far shorter duration (hours rather than days). Frostbite is freezing of tissue, with resultant tissue necrosis. Several conditions have been described as predisposing subjects to pernio, including the presence of cryoproteins, excessive cold exposure, and anorexia nervosa among children and systemic lupus erythematosus and antiphospholipid antibodies among adults. It is important, therefore, when evaluating a patient with pernio, both to exclude an underlying diagnosis and to determine whether additional testing is necessary. The lesions of acute pernio are usually self-limited but may lead to recurrent disease. The involved limb should be cleaned and dried, and rewarming should occur. Prevention is the best form of therapy, and cold exposure should be minimized after an initial insult. The prognosis for properly treated pernio is excellent. Nifedipine, which produces vasodilation, has been demonstrated to be effective in reducing pain, facilitating healing, and preventing new lesions of pernio. We think that the 5 cases seen in our rheumatology clinic represent an increase, compared with prior years; the dermatology clinic at the University of Colorado reported a series of 8 children treated during a 10-year period. The reasons for the possible increase are likely multifactorial, with cold climate, a vulnerable population with thin body habitus, and cold exposure all being contributing causes. Of note, the quality of cold in Colorado is quite dry; however, the winter of 2003 to 2004 was not particularly colder or drier than prior years. All patients were very thin, and thin body habitus may be associated with increased cutaneous vasoreactivity. It is also unclear how these cases of pernio may reflect that winter's fashion trends (2 patients reported wearing sandals in winter). General pediatricians, particularly those who practice in colder climates, should be aware of the presentation and treatment of pernio in childhood.