White spots on fingernails or toenails are common. These marks, often appearing as small dots or lines, are usually harmless and do not indicate a serious health concern, frequently resulting from everyday occurrences.
Understanding Leukonychia
The medical term for white discoloration of the nails is leukonychia, derived from the Greek words “leuko” meaning white and “onychia” meaning nails. Leukonychia can manifest in several forms. True leukonychia involves the nail plate itself, often due to issues in the nail matrix where the nail grows. Apparent leukonychia refers to discoloration originating from the nail bed beneath the nail plate, which may disappear with pressure. Pseudoleukonychia describes whiteness on the nail’s surface, typically caused by external factors.
Leukonychia can also be classified by its distribution. Punctate leukonychia appears as small white spots, while striate or transverse leukonychia presents as horizontal bands or lines. Longitudinal leukonychia, a less common form, shows as white lines running down the length of the nail. When the entire nail plate becomes white, it is termed total leukonychia, and partial leukonychia affects only a portion of the nail.
Common Causes of White Spots
Minor trauma to the nail matrix is the most frequent cause of white spots. This can result from daily activities such as bumping a finger, typing, or aggressive manicuring. The disruption to the nail’s keratin formation during an injury can lead to air being trapped between the nail layers, which appears as white spots. These spots typically grow out with the nail over several months.
Allergic reactions can also cause white spots on nails. Certain nail products, including polishes, hardeners, or removers, contain ingredients some individuals may react to. Such reactions can manifest as white discoloration. Identifying and avoiding the specific product helps resolve these marks.
Fungal infections are another common cause of white spots, particularly superficial white onychomycosis. This infection often appears as white, powdery patches on the nail’s surface. While many nail fungi cause yellow or brown discoloration and thickening, this specific type results in a distinct white appearance.
Nutritional deficiencies are sometimes linked to white spots, though the popular belief that calcium deficiency is the primary cause is largely a myth. Calcium deficiency typically affects nail strength and shape rather than causing white spots. However, deficiencies in certain other minerals, such as zinc, have been associated with white marks on the nails, particularly in cases of severe deficiency.
Less Common and Serious Causes
In some instances, white spots on nails can signal underlying systemic diseases. Conditions affecting organs such as the liver, kidneys, or heart can sometimes manifest with changes in nail appearance, including white discoloration. Examples include Terry’s nails, where most of the nail appears white with a narrow pink band at the tip, often associated with liver disease or heart failure. Lindsay’s nails, or “half-and-half nails,” show a white proximal portion and a darker distal band, which can be seen in kidney disease.
Certain medications can also induce leukonychia. Chemotherapy drugs can disrupt nail growth and lead to white bands across the nails, known as Mees’ lines. Other medications, such as some sulfonamide antibiotics, have also been reported to cause similar nail changes.
Exposure to heavy metals, particularly arsenic and lead, can cause white lines or spots on the nails. These toxic substances interfere with the normal growth process of the nail. While rare, this cause is serious and often accompanied by other symptoms of poisoning.
Very rarely, white spots on nails can be a manifestation of genetic conditions. These inherited forms of leukonychia are often part of broader syndromes that affect multiple body systems. Such genetic causes are typically observed from birth or early childhood and may involve all nails, sometimes with characteristic patterns.
When to Seek Medical Advice and Prevention
Consult a healthcare provider if white spots on your nails are widespread, persistent, or accompanied by other concerning symptoms. Seek medical evaluation if the white spots change in appearance, become discolored, or if you notice other nail abnormalities like cracking, brittleness, or ridges. It is also important if the white spots appear alongside systemic symptoms such as unexplained weakness, fatigue, blurred vision, or confusion.
Preventing white spots involves protecting your nails from trauma. Wearing gloves during activities that could cause injury, such as household chores or sports, helps. Ensuring appropriately sized footwear prevents toenail trauma. Maintaining good nail hygiene, including regular trimming and moisturizing, promotes nail health.
Choosing hypoallergenic nail products and avoiding those that cause irritation or allergic reactions also prevents white spots. If a fungal infection is suspected, prompt treatment limits its spread and impact on nail appearance. While most white spots are harmless and resolve on their own, recognizing when to seek professional medical advice ensures any underlying issues are addressed.