Living with Psoriasis/Hair, Nail, & Body Care

Keratin Buildup Under Toenails: What It Looks Like With Psoriasis

Medically reviewed by Paul A. Regan, M.D., FAAD

Written by Destiny Nkechi, M.D.

Posted on November 10, 2026

Feel better informed on psoriasis and get real support from your community.

Join

Key Takeaways

People with psoriasis may notice a buildup of thick, white or yellowish material under their toenails, which can be a sign of a condition called subungual hyperkeratosis, where excess keratin-containing skin cells collect beneath the nail.
Nail psoriasis can cause a range of changes to the toenails, including thickening, lifting, discoloration, and tiny dents on the nail surface, and while psoriasis is a common cause of these changes, fungal infections, repeated pressure from shoes, and other conditions can look very similar. A dermatologist can examine the nails and may take a small nail clipping to find out what is causing the changes.
If you notice persistent buildup under your toenails, talking with a dermatologist is a helpful first step, and before your appointment it can be useful to make note of when the buildup started, which nails are affected, and any history of psoriasis, joint pain, or treatments you have already tried.

View all takeaways

“How do I get rid of this buildup under my toenails? Wearing my work boots has become a nightmare,” one MyPsoriasisTeam member shared.

If you’ve noticed something similar and have psoriasis, subungual hyperkeratosis may be the cause. This happens when excess keratin-containing skin cells collect beneath the nail, causing it to thicken or lift. It’s a common sign of nail psoriasis, but fungal infections and repeated pressure or injury can also cause it.

Here’s what keratin buildup under toenails looks like, other signs to watch for, and when to see a dermatologist.

🗳️ Have you ever noticed buildup forming under your toenails?

Yes

What Is Keratin Buildup Under a Toenail?

Keratin is a protein that helps form your nails, keeping them strong and resilient. Normally, skin cells beneath your nails grow and shed in an orderly way.

With nail psoriasis, inflammation disrupts this process, causing excess keratin-containing cells to accumulate beneath the nail plate — the hard, visible part of your nail. This is called subungual hyperkeratosis.

Keratin buildup usually affects the nail bed (the skin beneath the nail plate) and is particularly common in toenails. As the material collects, it can make your nail appear thicker, raised, or separated from the skin underneath.

What Does Keratin Buildup Look Like With Nail Psoriasis?

In pictures of nail psoriasis, keratin buildup may appear as a thin layer of pale debris or thick, chalky material packed beneath the toenail. It can also occur alongside other nail changes, including lifting, discoloration, and pitting. Here are key features of subungual hyperkeratosis.

Thick, White or Yellow Buildup

Keratin buildup often looks like white or yellowish, flaky material beneath the toenail. It may collect near the tip or extend farther underneath, making the nail appear thicker or raised.

As the material accumulates, the nail may become harder to trim or press uncomfortably against your shoes.

One MyPsoriasisTeam member described how difficult nail care had become: “I can’t even get the toenail clippers around my nails.”

Nail Lifting

Sometimes, the toenail separates from the skin underneath. This is called onycholysis.

The lifted portion may appear white or yellowish, sometimes with a reddish border where the nail remains attached. The gap can also trap debris, making the toenail look even thicker.

“I have splinter hemorrhages, ridges, and nail lifting on my toenails,” one MyPsoriasisTeam member shared. “I am seeing my rheumatologist tomorrow to see if there’s anything they can do.”

Yellow or Orange Patches

Nail psoriasis can also cause yellow, orange, or reddish-brown patches beneath the nail. These are called oil spots or salmon patches because they resemble drops of oil trapped beneath the nail.

As one MyPsoriasisTeam member puts it: “At first, I thought my nail was just stained. Then I noticed these yellow patches underneath that wouldn’t go away, no matter how much I cleaned it.”

Unlike keratin buildup, these patches are areas of discoloration rather than accumulated debris.

Pitting and Crumbling

You may also notice tiny dents on the nail surface, called nail pits, or areas where the nail becomes rough or starts to crumble.

“My nails are ridged, and they splinter and crack along the ridges, so I keep them as short as possible,” one MyPsoriasisTeam member shared.

These changes may not be caused by keratin buildup. While buildup, nail lifting, and oil spots involve the nail bed, pitting and certain types of crumbling result from inflammation in the nail matrix — that is, the area where the nail plate grows. However, both types of changes can occur together.

How Is Subungual Hyperkeratosis Diagnosed?

If you notice persistent buildup under your toenails, book an appointment with a dermatologist. They’ll examine your nails, look for signs of psoriasis, and check whether another condition could be causing the changes.

Some conditions that can cause keratin buildup under the toes include:

Fungal nail infections — These can also cause thick, yellowish, crumbly toenails with debris underneath.
Repeated nail injuries — Pressure from tight shoes, running, or accidentally injuring a toe can cause the nail to thicken or lift.
Nail separation (onycholysis) — When the nail pulls away from the skin underneath, debris can collect in the gap. Nail separation can result from psoriasis, injury, or other conditions.
Eczema or contact dermatitis — Irritation or allergic reactions to nail products and other substances may cause nail changes that resemble psoriasis.
Rare nail disorders — Conditions such as pachyonychia congenita and yellow nail syndrome can cause significant nail thickening or discoloration. Your dermatologist may consider these if your symptoms or medical history suggest them.

Age-related nail thickening can also occur, but that doesn’t mean you have subungual hyperkeratosis.

What To Tell Your Dermatologist

Before your appointment, make a note of when the buildup started, which nails are affected, and whether you’ve noticed pain, discoloration, or lifting. Mention any history of psoriasis, joint pain or stiffness, nail injuries, and treatments you’ve already tried.

Your dermatologist may take a small nail clipping or gently scrape some material from beneath the nail to test for fungus. The sample is sent to a laboratory, where it may be examined under a microscope or tested using other methods.

One MyPsoriasisTeam member shared why testing can be helpful: “If you haven’t already, get a nail clipping test, as psoriasis can look very similar. Mine came back as a fungal infection.”

Most people won’t need a nail biopsy. Your dermatologist may recommend further testing if the diagnosis remains unclear.

Treatment and Nail Care

If psoriasis is causing keratin buildup under your toenails, treatment can help reduce inflammation and prevent further buildup. Your dermatologist will recommend an approach based on how many nails are affected and how severe your symptoms are.

For mild nail psoriasis, treatment may include prescription steroid creams or vitamin D-based medications, such as calcipotriol. Steroid injections around the nail may help if other treatments aren’t working. For more severe cases, especially if you also have skin psoriasis or psoriatic arthritis, your doctor may recommend medications that work throughout the body, including biologics or certain oral medications.

How To Care for Your Toenails at Home

Alongside treatment, these nail care habits can help protect your toenails:

Keep nails short — Trim them gently to reduce pressure and prevent further lifting.
Avoid digging underneath your nails — Scraping out buildup can damage the nail bed and increase the risk of infection.
Choose comfortable shoes — Wear shoes with enough room for your toes to avoid repeated pressure.
Keep nails clean and dry — Gently wash and dry your feet, and avoid picking at loose nails.
Ask about professional trimming — If a toenail is too thick or painful to cut, a dermatologist or podiatrist may be able to thin it safely.

Be patient with treatment. Toenails grow slowly, so visible improvement may take several months, even after inflammation begins to improve. Contact your dermatologist if you develop increasing pain, redness or discoloration, swelling, or drainage.

References