Nail psoriasis or nail fungus can cause discoloration, cracking, or separation from your nail bed. While the conditions share some similar symptoms, key points of differentiation exist.

Psoriasis is an autoimmune disease that typically causes skin scaling and discoloration due to skin cell overproduction. However, psoriasis can also affect your nails and nail beds.

Nail fungus is a localized infection caused by fungi that affects the tissues in and around your nails.

Although these conditions may look the same, differences between them are present.

Nail psoriasis and nail fungus symptoms are similar, and it may be difficult to tell them apart. It’s important to know which you have so you can treat it properly.

Both conditions can cause nail pitting, thickening, or structural changes but differ in other ways.

Symptoms of nail psoriasis

Nail psoriasis almost always occurs in people who have general psoriasis. It tends to affect fingernails more often than toenails.

Unique symptoms include:

  • nail yellowing or browning
  • detached nails from your nail bed, creating gaps that bacteria can infect
  • chalky buildup under your nail that causes your nail to lift
  • tenderness or pain if there’s buildup under your nails

Symptoms of nail fungus

Nail fungus is fairly common. It usually starts with a white or yellow spot under the tip of your fingernail or toenail.

Unique symptoms include:

  • nail color darkening
  • progressive nail shape changes
  • brittle or dull nails
  • a foul odor

The fungal infection can sometimes spread between your toes and onto the skin on your feet. That’s when you have a case of athlete’s foot.

You can have nail psoriasis and a fungal infection. However, the exact rate of this co-occurrence isn’t clear. A small 2021 study found that of 25 people in Bangkok with nail psoriasis, the co-occurrence rate of fungal infections in nail psoriasis was close to 35%.

Below are pictures highlighting the similarities and differences between nail psoriasis and nail fungus.

In addition to different causes and symptoms, nail psoriasis and fungus have different risk factors.

Risk factors for nail psoriasis

A 2021 research review of 66 international articles on nail psoriasis treatment estimated that 40–50% of people with psoriasis have nail psoriasis. While it’s common for psoriasis to affect the nails, it’s still unclear why some people with psoriasis have nail health effects while others don’t.

Risk factors for fungal infections

Fungi are tiny organisms that flourish in warm, moist environments. Showers and swimming pools are among their favorite hiding places. Any separation between your nail and nail bed is an open invitation for fungi to migrate. Even a microscopic cut in your skin can let them in.

You may be more likely to get nail fungus as you age. You can also have a higher risk of nail fungus if you:

  • sweat a lot
  • work in a moist environment, or your hands or feet are often wet
  • walk barefoot around public swimming pools, gyms, and showers
  • wear socks and shoes with little ventilation
  • have a condition that can weaken your immune system, such as HIV
  • live with someone who has nail fungus

People with circulatory conditions or diabetes may also have an increased risk of nail fungus. Any injury to your nail bed can also make you more likely to get nail fungus.

You won’t know how to treat it effectively unless you’re certain which condition you’re dealing with. If your symptoms are very mild, you may not need treatment.

When you have discoloration, pitting, or nail cracking, get help from a healthcare professional. This is especially important if you have psoriasis or diabetes.

In the meantime, try these tips:

  • Clean your feet and make sure to dry them thoroughly.
  • Trim your nails.
  • Disinfect and clean any manicure and pedicure tools you use.
  • Change your socks twice per day.
  • Wear shoes that fit properly and allow your feet to breathe.
  • Use shower shoes when visiting a public pool or locker room.

The treatment for nail conditions can depend on the cause.

Treatments for nail psoriasis

Nail psoriasis can be hard to treat. You can try topical medications, but they don’t always work. Other treatments may include:

In severe cases, doctors can surgically remove nails so new nails can grow in.

Treatments for nail fungus

Over-the-counter antifungal agents may treat some nail fungus cases. If those don’t work, a doctor may do a culture to determine the cause of the fungus. Prescription-strength topical or oral antifungals may be necessary. Doctors can remove parts of the nail that have nail fungus, too.

Be patient as nails grow slowly. It may take a long time to see the treatment results.

Nail psoriasis and fungal nail infections share similar symptoms, such as discoloration, cracking, or nail separation from your nail bed. However, the two conditions differ in crucial other ways.

For example, fungal infections can cause nail darkening and a foul odor, while nail psoriasis more commonly causes nail yellowing and chalky buildup around your nail.

The two conditions also have distinct causes, risk factors, and treatments.