<unk>  is the absence of finger- and/or toenails, an 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.
Anonychia
Paronychia
Leukonychia
Chromonychia
Melanonychia
Platonychia
Macrodontia 
Aspermia