A 68-year-old woman from Idaho presented in February with complaints of burning, painful reddish-blue skin changes in four of her right and three of her left toes. These changes have recurred for the past 3 years appearing in the fall and resolving in the spring; specifically, skin changes are absent during the warmer seasons. Blistering and superficial ulcerations were described in the first year yet they were subsequently preventable by wearing well-insulated shoes and warm socks. She has no peripheral arterial disease (PAD) and underwent extensive workup, which was unrevealing. Her serologies were negative for rheumatic diseases, and the nail fold capillaries pattern was normal. She had marked improvement after a week of nifedipine treatment. A diagnosis of pernio was ultimately made.

• 
  

  More common in geographic areas with moist cold conditions.¹

  
  
• 
  

  Occurs more frequently among women than men.^{1,2, and 3}

  
  
• 
  

  More common in young and middle age, although patients of any age and race may be affected.

  
  
• 
  

  Low body mass is common.

• 
  

  Intermittent or prolonged cold exposure with local hypoxemia and localized inflammation.⁴

  
  
• 
  

  Typically an essential process affecting susceptible individuals, but some cases are seen in association with connective tissue disorders where pernio may be their early or the only sign.^3,5,6

  
  
• 
  

  PAD and/or vasospastic disease is a risk factor.

The diagnosis is clinical, and laboratory studies and biopsies are not helpful (unless alternative diagnoses have to be ruled out). The key historic factor to establishing the diagnosis is cold exposure. It precedes skin changes by less than 1 day to several decades. The skin lesions are persistent and recur during the cold season or with repeat cold exposure; they disappear in warm climate or with stable warm weather.^1,7

Clinical Features

• 
  

  Acute or repeat cold exposure history is identifiable.¹ The cold is typically nonfreezing and moist, rather than dry.^7,8

  
  
• 
  

  The onset and spontaneous disappearance of the lesions are noted in relation to prevailing ambient temperature. Many patients go through multiple cycles.¹

  
  
• 
  

  The lesions are typically macules, less frequently nodules, papules, or plaques, with color changes ranging from blue to erythematous with doughy subcutaneous swelling. Occasionally they may ulcerate, form vesicles, or hemorrhage with variable stages of resolution present at the same time^1,2,7 (Figures 87-1,87-2, and 87-3).

  
  
• 
  

  Symptoms often include local itching, burning, or pain.⁷

  
  
• 
  

  Digital paresthesia may be present.¹

  
  
• 
  

  Capillary refill time ranges from normal to prolonged.⁸

  
  
• 
  

  Multiple clinical variants and synonymous terms are known.⁹

  
  
• 
  

  More commonly an isolated benign condition but may be observed with connective tissue diseases and then is marked by greater persistence beyond the cold season.³