| • | rare genodermatosis, autosomal dominant |
| • | skin, nails, and oral mucosa oral leukokeratosis (NOT premalignant) |
| • | classified into four types with increasing clinical symptoms |
| • | nail changes with palmoplantar keratoderma |
| • | all 20 nails affected: yellow-brown pincer nails show subungual hyperkeratosis and become progressively thicker |
skin:
| • | follicular keratosis on elbows and knees |
| • | palms and soles - keratoderma +/- frictional blisters |
type I - keratins 6 and 16
type II - keratin 17; clinically resembles type I with the addition of natal teeth and steatocystoma multiplex)
ddx:
| • | other palmoplantar keratodermas |
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