A skin biopsy of one of the lesions on the right toe showed dermal edema with an associated lymphohistiocytic infiltrate. There are scattered areas of perieccrine involvement and areas of vasculitis. Laboratory work up showed a normal complete blood count, a negative antinuclear antibodies (ANA) titer, a negative double-stranded DNA, normal levels of inflammatory markers, and negative cryoglobulins and cold agglutinins. The patient was diagnosed with pernio. The lesions improved within several weeks. She now wears thicker socks when she is ice skating.
Children, women, and the elderly are at a higher risk.1 This condition is frequently described in Northwestern Europe and the United Kingdom, especially in those living in houses without central heating.2
Clinically, the lesions appear a few hours or days after cold exposure on the toes, fingers, and in some unusual cases on the nose and the ears. The lesions present as erythematous to violaceous macules, papules, or nodules that in severe cases may blister and ulcerate. The lesions may be asymptomatic, pruritic, or tender. In children, pernio can be associated with the presence of cryoglobulins, cold agglutinins, anorexia nervosa, and genetic interferonopathy; it may precede the diagnosis of chronic myelomonocytic leukemia and may occur as a presenting sign of a blast crisis in acute lymphoblastic leukemia.3,4 The skin lesions usually resolve within days to a few weeks. Histopathologic analysis shows dermal edema with associated superficial and deep lymphohistiocytic infiltrate and perieccrine involvement.
The differential diagnosis of pernio includes other cold-induced syndromes such as Raynaud’s syndrome, cold panniculitis, cold urticaria, livedo reticularis, acrocyanosis, and chilblain lupus. In chilblain lupus (a form of chronic cutaneous lupus), the lesions may be very similar to pernio but the histopathology is consistent with changes of discoid lupus. Lesions of idiopathic palmoplantar hidradenitis present as erythematous tender nodules on the palms and the soles.5 The lesions can be triggered by vigorous physical activity, exposure to moisture, and excessive sweating. White, blue, and red discoloration of the fingers is seen in Raynaud’s phenomenon rather than the fixed erythematous to violaceous macules, papules, or nodules seen in pernio. Patients with erythromelalgia present with red painful palms and soles triggered by heat and, in contrast to pernio, relieved by cooling. Sweet syndrome, a febrile neutrophilic dermatoses, is characterized by tender erythematous papules and plaques with associated systemic symptoms. These patients may have an associated internal malignancy or infection, or the disorder may be triggered by medications or pregnancy.
Our patient had no systemic symptoms, and the pathology didn’t show any neutrophils. When the diagnosis is in doubt, a skin biopsy may help elucidate the diagnosis.
Once the diagnosis of pernio is made, it is recommended to order a complete blood count to rule out blood malignancies and cryoproteins.
Treatment of this condition consists of rewarming the extremity. If rewarming does not improve the patient’s symptoms, systemic treatment with nifedipine may be warranted.
Dr. Matiz is a pediatric dermatologist at Southern California Permanente Medical Group, San Diego. Dr. Matiz said she had no relevant financial disclosures. Email her at.