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clinical: 
| • | slightly raised or level with the surface of the skin (later depressed) |  
 | • | typically the surface shows prominent dilated pilosebaceous or sweat duct orifices which often contain yellow or brown, horny plugs |  
 | • | petechiae = clue to diagnosis |  
 | • | ddx:  morphea, atrophic LP |  
 | • | ¾ of female patients have one or more organ specific auto-antibody (e.g. thyroid or gastric parietal cells) |  
 | • | LS&A of the penis (aka balanitis xerotica obliterans) - occurs on the glans penis (follicular plugging absent because there are no follicles on the glans) |  
 | • | may degenerate into SCC (especially in the vulva)  |  
   
LS and A of the vulva: 
| • | spares the vagina (vulva only) |  
 | • | telangiectasia makes the diagnosis |  
 | • | ddx: intertrigo with atrophy secondary to strong topical glucocorticoids |  
   
mnemonic (to remember affect age group for these diseases): 
| • | vulva LS et A in women:  most common before puberty often will spontaneously improve upon puberty and after menopause |  
 | • | an exact opposite to Fox-Fordyce disease: which begins after puberty and may remain until menopause |  
   
histology: 
| • | thinning of the epidermis but hyperkeratosis  |  
 | • | vacuolar alteration of the basal layer |  
 | • | lymphedema of the papillary dermis;  bleeding into skin due to capillary fragility (like the pinch purpura of amyloid) |  
 | • | beneath the edema there is a diffuse, perivascular infiltrate of lymphocytes in the mid dermis |  
  
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