White discoloration on toenails can be a common observation, often referred to medically as leukonychia. This change in nail appearance can range from small spots or streaks to a complete whitening of the nail plate. While frequently harmless, white toenails can sometimes indicate an underlying condition, making it helpful to understand the various potential causes.
Primary Causes of White Toenails
Fungal infections, or onychomycosis, are a frequent cause of white toenails. They often begin as a white or yellow-brown spot under the nail tip and can spread, causing the nail to discolor, thicken, and become crumbly. These infections can result from exposure in moist environments or prolonged wear of sweaty shoes and socks. Superficial white onychomycosis, a specific type, invades the top layers, leading to flaky, white patches and a powdery texture.
Physical trauma to the toenail is another common reason for white marks. This can occur from a single impact, such as stubbing a toe, or from repetitive pressure, like wearing shoes that are too tight during activities or exercise. When trauma occurs without causing bleeding, a white spot or line may appear and will gradually grow out with the nail. This type of discoloration is often seen on the big toe.
Psoriasis, an autoimmune condition, can also affect the nails, leading to white discoloration. Nail psoriasis can cause the nail to turn white, yellow, or brown, and may also result in tiny dents or pits on the nail surface. This condition can lead to a chalky substance accumulating under the nail, which can be painful if pressure is applied.
Keratin granulation, also known as superficial whitening, is a common cause of white patches on toenails. This condition appears as chalky white, rough, or uneven patches on the nail surface. It often results from prolonged nail polish use, particularly with acetone-based removers, which dehydrate superficial nail cells. While not a fungal infection, dehydrated nails from keratin granulation can become more susceptible to fungal growth.
Distinguishing Characteristics and Other Symptoms
White spots or streaks caused by trauma appear where the injury occurred and grow out with the nail over several months. If the trauma is repetitive, such as from ill-fitting footwear, white lines may appear across the nail. These marks do not involve changes in nail texture or surrounding skin.
In contrast, fungal infections like onychomycosis present with a chalky white, powdery, or crumbly texture on the nail surface. The infection can cause the nail to thicken, become brittle, or even separate from the nail bed. Sometimes, a fungal infection can also lead to yellowing or browning of the nail, and the skin around the nail could become inflamed.
Nail psoriasis can manifest with white discoloration, often accompanied by other specific signs. These include pitting, small indentations on the nail surface, and onycholysis, where the nail separates from the nail bed. Psoriasis may also cause the nail to thicken or crumble, and a chalky buildup can occur under the nail.
Keratin granulation appears as superficial white, chalky, or smudged marks on the nail plate, often noticed after removing nail polish. These patches are due to dehydrated nail cells and do not involve the underlying nail bed or cause structural changes to the nail’s thickness or shape. They feel rough to the touch and indicate surface damage.
When Professional Medical Advice Is Needed
Professional medical advice for white toenails is important in several situations. If the white discoloration spreads, worsens, or is accompanied by pain, swelling, or redness around the nail, a doctor’s evaluation is recommended. This is particularly true if home remedies have not been effective.
Individuals with underlying health conditions, such as diabetes or a compromised immune system, should consult a healthcare provider if they notice changes in their toenails, as these conditions can increase the risk of complications. A medical professional can diagnose the cause through examination and sometimes by testing a nail sample for fungal presence. If multiple nails are affected symmetrically, or if the white appearance disappears when pressure is applied, it could indicate a systemic health issue.
Maintaining Toenail Health and Prevention
Practicing good foot and toenail hygiene is important for preventing white toenail issues. Regularly washing feet with soap and water, paying attention to the areas between the toes, and thoroughly drying them afterward helps prevent moisture buildup that can lead to fungal growth. Keeping toenails trimmed straight across and not too short also helps maintain their health.
Wearing appropriate footwear plays an important role in prevention. Opt for shoes that fit well, allowing toes to move freely and preventing repetitive trauma to the nails. Breathable materials for shoes and socks, such as wool or bamboo, can help keep feet dry and reduce the risk of fungal infections. Giving nails breaks from nail polish and using non-acetone removers can help prevent keratin granulation and nail dehydration.