Nail pitting is when you have tiny dents in your fingernails or toenails. It can be a sign of psoriasis, eczema, or joint inflammation. You might also get them if they run in your family. Let’s look at some of these causes.
Psoriasis
Psoriasis is a common and ongoing skin condition that causes your skin cells to build up very quickly. It tends to come and go. It can happen anywhere on your body, often in several areas at the same time. Some people see it in their nails, too.
It’s possible for your nails to be the only affected body part, but it’s rare. That’s why pitting can be an important clue there’s something going on elsewhere in your body.
Psoriatic Arthritis
Psoriatic arthritis is also ongoing and causes stiffness, swelling, and pain in your joints and where your ligaments and tendons attach to your bones. Nail pitting is the most common symptom. Inflammation in your nail matrix (what causes your nails to grow) triggers pitting.
Your nails can give a clear picture of how psoriatic arthritis progresses. Compare the length of the pits with stretches of healthy nail growth to track how the condition comes and goes.
Reactive Arthritis
You might see nail pitting if you have reactive arthritis, which used to be called Reiter’s syndrome. It happens after a bacterial infection in your intestines, genitals, or urinary tract.
Reactive arthritis isn’t common. Scientists think it’s genetic -- about half the people who get it have the same gene.
Eczema
Pitting can happen if you have eczema on your hands and feet. It might be uneven and rough compared to more uniform patterns that show up with other conditions.
You might see pitting if eczema runs in your family. Most people who report it have a long history with eczema. Your nails usually return to normal as your eczema gets better.
Alopecia Areata
This autoimmune condition causes hair loss on your head and body. Your nails may break easily, and dents can form. The pitting tends to be finer than the rough dents caused by other conditions.
Lichen Planus
This causes swelling and irritation in your hair, skin, nails, and mucous membranes. Researchers aren’t sure why it happens, but hepatitis C, certain drugs, flu shots, and some metals and chemicals seem to trigger it. It’s most common in middle-aged people.
Incontinentia Pigmenti
Also known as Bloch-Sulzberger syndrome, this rare genetic condition causes different symptoms. People who have it tend to be short, have smaller and fewer teeth, and eyes that are smaller than normal. There are many more symptoms, but nail pitting is a common one. Incontinentia pigmenti affects more women than men. Males with it usually die before birth.
Sarcoidosis
This disease causes small clusters of inflammatory cells to form in the lymph nodes and lungs. But it can affect the skin and other organs, too. Changes in your nails are rare. Nail pitting is even rarer, but it happens.