Koilonychia

When it comes to nail conditions that may point to an underlying health concern, nail techs can be a crucial help to clients by pointing them to a medical professional for further observation or testing. The phenomenon called koilonychia, which presents as “spoon-shaped” nails, is one of those conditions—caused by a range of potential culprits, some potentially serious and requiring further medical attention. By learning a bit about koilonychia, including its appearance and causes, you will be well-equipped to lend a helping hand and safely proceed with your nail services.

What To Look For

When describing koilonychia, Jeffrey M. Weinberg, M.D., clinical professor of dermatology at Icahn School of Medicine at Mount Sinai in New York City, points to the comprehensive article “Nail Abnormalities: Clues To Systemic Disease” by Robert S. Fawcett, M.D., M.S.; Sean Linford, M.D.; and Daniel L. Stulberg, M.D., published in a 2004 volume of American Family Physician. “Koilonychia is represented by transverse and longitudinal concavity of the nail, resulting in a ‘spoon-shaped’ nail,” the article states. “This abnormality is sometimes a normal nail variant in infants, but it usually corrects itself within the first few years of life.” However, Weinberg adds that koilonychia is not very common in adults.

According to Shari Lipner M.D., Ph.D., associate professor of clinical dermatology and director of the nail division at Weill Cornell Medicine in New York City, if you are looking at a concave (curved inward) nail shape, you may be seeing koilonychia. “An easy way to test for koilonychia is to put a drop of water on the nail—for a person with koilonychia, the water will stay on the nail and not fall off,” Lipner explains. “People with koilonychia usually have no other symptoms, and the nails are not painful.”

Koilonychia Facts*

• The term “koilonychia” is derived from the Greek word “koilos,” which means hollow, and “onikh,” which means nail.
• 5.4% of patients with koilonychia have iron-deficiency anemia, inflammatory skin disease and onychomycosis.
• In newborns, koilonychia presents as a normal variant in 33% of cases, especially affecting the big toe, which regresses spontaneously after the age of nine once the nail plate thickens and hardens.
• Koilonychia is considerably more prevalent in developing countries: 36%, or 1.4 billion out of a 3.8-billion estimated population in developing countries, versus 8%, or just under 100 million out of a 1.2- billion estimated population in developed countries.
• When koilonychia is related to anemia, the nails return to normal within four to six months of increasing iron intake. 

*“Spoon Nails” by Dipali G. Rathod and Sidharth Sonthalia

A Multitude of Causes

Chris G. Adigun, M.D., FAAD, a board-certified dermatologist at Dermatology & Laser Center of Chapel Hill in Chapel Hill, North Carolina, notes that koilonychia can be an important clinical clue to a variety of dermatological diseases. These include psoriasis, lichen planus, alopecia areata, onychomycosis (a fungal infection of the nails) and genodermatoses (a hereditary skin disease). But, it may also result from nondermatological causes, such as iron-deficiency anemia, hypothyroidism, hyperthyroidism and diabetes mellitus.

Repeated occupational trauma is another possible culprit, so you might even see koilonychia among your co-workers in the salon. “Repeated skin-irritant exposure—most often occupational, such as chemical exposures for hairdressers, or repeated water exposure among foodservice and healthcare workers, may also be a cause of koilonychia,” Adigun says. “Atopic dermatitis, or chronic hand dermatitis, may also eventually cause koilonychia if it has been a longstanding issue.”

However, Weinberg adds that, most commonly, koilonychia is a manifestation of chronic iron deficiency, which may result from a variety of causes. “These include malnutrition, gastrointestinal blood loss, gastrointestinal malignancy and celiac disease,” he says. “Additional causes of koilonychia are high altitude, trauma and exposure to petroleum products. It can even be hereditary.”

Lipner adds a few more possible causes: heart disease, systemic lupus erythematosus and Raynaud’s phenomenon. Fawcett’s report also notes nail-patella syndrome as a potential cause; this is an inherited condition that can also include “hypoplastic, easily dislocated patellas; renal and skeletal abnormalities; and glaucoma.” Interestingly, the report states that koilonychia also “occasionally occurs in patients with hemochromatosis,” which is a disorder in which extra iron builds up in the body—in other words, the opposite issue of iron deficiency or anemia. Hence, when spoon nails are present without an obvious associated illness, the report notes that physicians should order a complete blood count and ferritin test, to determine if iron deficiency or hemochromatosis is causing the issue.

How You Can Help

Although not required or trained, nail techs are in a prime position to notice nail abnormalities—and potentially help the client by recommending a physician’s checkup. “If this presentation is observed, then referral to a dermatologist would be helpful,” Weinberg says. “Nail professionals [can] go online and Google images of this condition to familiarize themselves with the clinical presentation. Koilonychia is diagnosed by clinical evaluation, and after a laboratory workup, if iron deficiency is present, supplements may be helpful to improve the nails’ appearance.”

Luckily, in the case of koilonychia, your client should not have to submit to arduous tests, at least initially. “Koilonychia is diagnosed with a careful physical examination, and no nail biopsies are generally needed,” Lipner explains. “If your dermatologist suspects psoriasis or onychomycosis, a noninvasive nail clipping is taken. For many of the other conditions that might cause koilonychia, blood testing can help determine the cause of the koilonychia.”

Though Lipner notes that there are no direct treatments for koilonychia, the condition will improve if the underlying problem is treated—for example, if the patient has onychomycosis, an antifungal medication will be prescribed to treat the problem and therefore improve or eradicate the koilonychia symptoms.

But, in the meantime, how should you work with clients if koilonychia is an issue? Are there any things you can do to help, or are there nail care steps you should avoid? Though nail techs should not diagnose or treat nail disesases or disorders, Lipner advises “Nail technicians [can get] familiar with the presentation of koilonychia so the client [may] be referred to a board-certified dermatologist for diagnosis and treatment. In addition, people with koilonychia may benefit from gel manicures. With that treatment, the indentation or concavity in the nail is filled in, with the result that the nail looks better esthetically and is more functional.”

Sources: “Nail Abnormalities: Clues to Systemic Disease,” by Robert S. Fawcett, M.D., M.S., Sean Linford, M.D., and Daniel L. Stulberg, M.D.

About the Author 

Tracy Morin is a freelance writer and editor based in Oxford, Massachusetts.