anonychia

https://doi.org/10.1351/goldbook.10403
Absence of nails.
Note: This rare disorder may be the result of a congenital defect of ectoderm, ichthyosis, severe infection, severe allergic contact dermatitis, self-inflicted trauma, Raynaud phenomenon, lichen planus, epidermolysis bullosa, or severe exfoliative diseases.
Source:
PAC, 2016, 88, 713. (Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)) on page 724 [Terms] [Paper]