Nails in Common Diseases
The nail unit reflects more than local problems or heart and lung disease. It also mirrors the body's metabolic and hormonal state and the health of internal organs such as the kidneys, liver, thyroid and blood-forming system.
Because the tissue beneath the nail bed is packed with capillaries and has no layer of fat, any change in plasma albumin, buildup of uremic toxins, bilirubin, thyroid hormone imbalance or micronutrient deficiency (iron/ferritin) can leave characteristic separation, discoloration or changes in shape in the nail plate and nail bed.
Nail signs of internal disease are usually painless, so patients rarely seek care for them. At Haute-Derma, accurately identifying Lindsay's, Terry's and Plummer's nails or spoon nails with onychoscopy works as a quick screening test, helping to detect silent kidney failure, early cirrhosis, thyroid disease or chronic anemia before obvious symptoms appear.
Our Multi-Organ Screening Approach at Haute-Derma
When we find systemic changes in nail color or shape, our doctors follow a multi-organ onychoscopy and capillaroscopy screening protocol (Haute-Derma Systemic Nail Screening Protocol):
High-Resolution Onychoscopy and the Blanching Test
- Digital magnification: Assesses color boundaries, the width of the distal band and the state of the lunula.
- Nail bed blanching test: Gentle pressure on the nail plate with the dermatoscope distinguishes fixed tissue pigmentation (Lindsay's nails) from temporary vascular edema (Muehrcke's lines, Terry's nails).
- Drop test: A drop of saline placed on the nail plate confirms spoon nails (koilonychia).
Referral for Laboratory Testing
- Suspected Lindsay's nails: Prompt testing of creatinine, blood urea, eGFR and urinalysis to screen for chronic kidney disease.
- Suspected Terry's nails / Muehrcke's lines: Albumin/globulin, AST, ALT, total bilirubin and abdominal ultrasound to screen for liver or heart disease.
- Suspected Plummer's nails / spoon nails: TSH and FT4 (thyroid screening), or complete blood count (CBC), ferritin and serum iron (anemia screening).
