Nail pitting refers to small, pin-sized dents or depressions in the surface of your fingernails or toenails. These tiny holes make the nail plate look rough or bumpy instead of smooth, almost as if someone poked the surface with a needle. While a single pit here or there can be meaningless, a pattern of recurring pits often signals an underlying condition, most commonly psoriasis.
What Nail Pitting Looks Like
The pits themselves are small, shallow indentations scattered across the nail surface. They can appear on one nail or many, and they vary in size, depth, and arrangement depending on the cause. In psoriasis, pits tend to be deep and irregularly spaced. In alopecia areata (an autoimmune condition that causes hair loss), the pitting is typically finer and more uniform, sometimes forming a grid-like pattern across the nail. Eczema and dermatitis produce coarser, more irregular pits.
One key feature separates nail pitting from other nail dents: it’s not caused by injury, and it doesn’t go away on its own. If you bang your finger and the nail looks rough for a while, that damage grows out as the nail replaces itself. Nail pitting is different. The dents keep appearing in new nail growth because the problem is in the tissue that produces the nail, not in the nail itself.
Nail pitting is also distinct from Beau’s lines, which are horizontal ridges or grooves that run across the nail. Beau’s lines are often triggered by illness, nutritional deficiency, or trauma and typically affect all nails at once. Vitamin deficiencies in iron or zinc can cause Beau’s lines or spoon-shaped nails, but they don’t cause pitting.
How Pits Form
Your nails grow from a structure called the nail matrix, a pocket of tissue tucked under the skin at the base of each nail. When this tissue is healthy, it produces a smooth, even nail plate. When it’s inflamed, the cells it produces are defective. Small clusters of abnormal cells create weak spots in the nail plate, and as the nail grows out, those weak spots crumble away, leaving behind the characteristic pits.
In psoriasis, researchers have found elevated levels of inflammatory signaling molecules (including TNF-alpha, IL-6, and IL-8) in affected nails, the same inflammatory markers found in psoriatic skin lesions. The inflammation disrupts the orderly production of nail cells in the matrix, and the visible pitting is the downstream result.
Conditions That Cause Nail Pitting
Psoriasis is the most common culprit. In a study of 621 psoriasis patients, 37% had fingernail pitting. But psoriasis is far from the only cause. Several other conditions can inflame the nail matrix enough to produce pits:
- Alopecia areata: produces fine, uniform pitting, sometimes called “sandpaper nails”
- Eczema or dermatitis: tends to cause coarser, irregularly shaped pits
- Lichen planus: a condition that causes inflammation in the skin and mucous membranes
- Chronic paronychia: long-term infection or inflammation around the nail fold
- Fungal nail infections: can occasionally produce pitting alongside other nail changes
In rare cases, uniform pitting across the entire nail plate appears as a developmental anomaly with no underlying disease. It’s also worth noting that mild pitting isn’t exclusive to people with diagnosed conditions. In one study, about 10% of people without any skin disease had some degree of nail pitting, so a few scattered dents don’t automatically mean something is wrong.
The Connection to Psoriatic Arthritis
For people with psoriasis, nail pitting carries a specific warning. Pitting has been identified as the only nail change that significantly predicts the development of psoriatic arthritis, a form of inflammatory arthritis that affects joints. A pooled analysis of studies found that psoriasis patients with nail pitting had roughly twice the risk of developing psoriatic arthritis compared to those without pitting (a hazard ratio of 2.14).
This doesn’t mean nail pitting guarantees joint problems. It means the inflammation affecting the nail matrix may reflect a broader inflammatory process that can eventually involve the joints. If you have psoriasis and notice pitting, it’s useful information to share with your dermatologist or rheumatologist, especially if you’re also experiencing joint stiffness or pain.
How Nail Pitting Is Treated
Treatment targets the underlying condition, not the pits themselves. You can’t fill in or smooth out existing pits. The goal is to reduce inflammation in the nail matrix so that new nail growth comes in healthy. That means you won’t see results quickly. Fingernails take about four to six months to fully grow out, and toenails can take up to 18 months, so even with effective treatment, visible improvement is a slow process.
For psoriasis-related pitting, dermatologists often start with topical treatments applied directly to the nail. A vitamin A derivative called tazarotene can improve pitting, nail discoloration, and nail separation, though it may irritate surrounding skin. A vitamin D derivative called calcipotriol helps with the buildup of thickened skin beneath the nail. Topical corticosteroids are another common option.
If topical treatments don’t produce results, stronger systemic approaches are available. For people with moderate to severe psoriasis, medications that calm the immune system (including biologics) can improve nail symptoms along with skin symptoms. These take longer to show effects on nails than on skin, sometimes six months or more, simply because of how slowly nails grow.
When the underlying cause is something other than psoriasis, treatment follows that condition’s management plan. Controlling eczema flares, treating fungal infections, or managing alopecia areata can all lead to healthier nail growth over time.
What You Can Do at Home
While treatment addresses the root cause, a few habits help protect pitted nails from further damage. Keep your nails trimmed short to reduce the chance of catching and tearing. Avoid picking at or peeling away rough nail surfaces, which can worsen the damage. Moisturizing the nail and cuticle area helps maintain flexibility in the nail plate, making it less prone to cracking. If the appearance bothers you, gentle buffing can smooth mild pitting, and nail polish can camouflage the uneven texture.
Pitted nails are more fragile than healthy nails, so they’re more susceptible to breakage during everyday tasks. Wearing gloves for wet work or heavy cleaning protects both the nail plate and the surrounding skin from irritation that could worsen the underlying inflammation.