Section 20: Thickened Nails
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Pachyonychia congenita
PC type 2 with thickening and discoloration of child’s toenails.
PC type 2 with painful keratoses on child’s soles.
CLINICAL FEATURES
Normal newborns have thin short nails. Those born with thick nails should bring to mind pachyonychia congenita. There are two types. Both types have thickened nails within the newborn period with the nails raised distally and discolored by subungual keratoses. Both types also have palmoplantar keratoses and oral mucosa whitening. Additional findings more common in type 2 include the presence of teeth at birth, blisters and excessive sweating on the palms and soles and benign growths of sebaceous glands called steatocystoma multiplex. PC type 1 is due to mutations in either keratin 6a or 16 and type 2 due to mutations in keratin 6b or 17.
TREATMENT
Local keratolytics such as 40% salicylic acid or 40% urea cream applied to the nails will help. Oral retinoids have aided in extreme involvement.