The abnormal upward curve to the fingernails was consistent with a diagnosis of koilonychia—otherwise known as spoon nails.
Koilonychia is an abnormal nail growth pattern where the distal nail matrix is depressed below its normal level, resulting in the spoon shape. The reverse, where the distal nail matrix is elevated in contrast to the proximal nail matrix, results in clubbing.1
There are multiple factors and diseases that result in koilonychia, including lichen planus, psoriasis, nutritional deficiencies (including iron deficiency anemia), and endocrinopathies.1 Lichen planus, which can cause koilonychia, often affects multiple nails and can also cause an associated central ridge pattern. Psoriasis may display a range of nail abnormalities; these include koilonychia, pitting onycholysis, and oil staining.
This patient did not have any signs or symptoms of psoriasis or lichen planus of her nails or skin. A review of her laboratory tests on file made no mention of anemia. Her chemistry profile—including liver tests, renal function tests, and protein levels—were all normal except for glucose levels, which was consistent with her prediabetes. Her thyroid function was also normal. No additional testing was performed since she had no symptoms, physical exam findings, or laboratory clues that pointed to other diseases or systemic processes.
The patient was advised to pick up over-the-counter nail strengtheners and to keep her fingernails trimmed short to minimize the likelihood of painful distal splitting that often occurs with brittle nails. Her physician advised her to follow up with the primary care team if she developed any new signs or symptoms.
Photo and text courtesy of Daniel Stulberg, MD, FAAFP, Professor and Chair, Department of Family and Community Medicine, Western Michigan University Homer Stryker, MD School of Medicine, Kalamazoo.