<unk>  is the absence of nails, a rare anomaly, which may be the result of a congenital ectodermal defect, ichthyosis, severe infection, severe allergic contact dermatitis, self-inflicted trauma, Raynaud phenomenon, lichen planus, epidermolysis bullosa, or severe exfoliative diseases.:784
Anonychia
Paronychia
Leukonychia
Melanonychia
Platonychia
Aspermia
Xerophthalmia
Onychia