| • | AKA perniosis or chilblains |  
 | • | common;  symptomatic skin lesions, which are precipitated by exposure to a moderate degree of cold in a humid climate |  
 | • | itchy or painful;  papules or plaques;  may have overlying blisters or ulcers |  
 | • | often superimposed on a background of acrocyanosis or erythrocyanosis |  
 | • | ddx:  secondary pernio of chilblain LE |  
 | • | superficial perniosis – bilaterally symmetrical and acral (digits, heels, nose, and ears) |  
 | • | deep perniosis – thighs and buttocks (histologically extends to the subcutis)  |  
 | • | treatment:  keeping feet dry;  nifedipine  |  
  
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