Nail Psoriasis vs. Fungus: What’s the Difference?

Medically Reviewed By Joan Paul, MD, MPH, DTMH

It may be hard to tell the difference between nail psoriasis and nail fungus. Both conditions can result in thickening, pitting, or deformation of the nails. However, people with nail psoriasis may notice blood under their nails, while people with nail fungus may experience itching or notice a nail odor. These conditions also have different causes. Nail psoriasis is thought to result from an overactive immune system, whereby the body mistakenly attacks healthy skin cells. Nail fungus results from fungal growth or infection.

This article looks at the differences between nail psoriasis and fungus, including symptoms, causes, diagnosis, and possible treatments.

What are the signs and symptoms of nail psoriasis and fungus?

A woman with long nails twirling her hair in her fingers
Léa Jones/Stocksy United

The signs and symptoms of nail psoriasis and fungus can be similar. However, there are some notable differences between them.

Nail psoriasis signs and symptoms may include Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source :

  • pitting of the nails
  • thickening of the nails 
  • subungual hyperkeratosis, or thickening and hardening of the skin underneath the nail
  • deformation of the nails 
  • blood under the nail
  • crumbling or splitting of the nails 
  • tenderness or pain in the affected nail
  • onycholysis, or separation of the nail from the nail bed 
  • salmon patches, or yellow or orange patches under the nail 
  • white lines on the nail

Learn more about what different types of psoriasis look like.

Signs and symptoms of nail fungus may include:

  • thickening, pitting, or deformation of the nails
  • discoloration of the nail, which may appear Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source white, yellow, or brown
  • cracking of the nail
  • itching 
  • subungual hyperkeratosis
  • brittle and dull nails
  • distorted nail shape
  • an odor from the affected nail 
  • separation of the nail from the nail bed

Some people may also experience Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source a fungal skin infection alongside nail fungus.

Learn 7 things to know about toenail fungus.

What causes nail psoriasis and fungus?

The exact cause of nail psoriasis is not fully understood. However researchers believe Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source it develops from a combination of genetic, immunologic, and environmental factors.

An overactive immune system may be a contributing factor in the development of nail psoriasis. This is when the body mistakenly attacks healthy skin cells, causing an inflammatory response. As a result, skin cells may accumulate on the surface of the nails. This can cause signs such as thickening of the nails.

Nail fungus, also known as onychomycosis, is caused by Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source fungi such as dermatophytes, yeasts, and molds. Fungi can infect the nail bed and plate, causing the nails to thicken, change color, and crumble.

Nail fungus is highly contagious. It can spread from person to person through contact with infected nail clippings, skin, or surfaces.

Learn more about what your nails can tell you about your health.

What do nail psoriasis and fungus look like? 

View the slideshow below for photos of nail psoriasis and fungus.

1-nail-psoriasis-body4-300x169.jpg

Nail psoriasis can cause nail pitting or splitting.

sweetheart studio/Shutterstock

2-psoriatic-arthritis2010-300x300.jpeg

People with nail psoriasis may also notice blood under their nails.

James Heilman, MD, CC BY-SA 3.0, via Wikimedia Commons

3-shutterstock-1652589460-300x206.jpg

Nail fungus can cause nail discoloration and may result in the nail separating from the nail bed.

Shutterstock

4-toenail-fungus-1296x728-galley-slide1-300x169.jpg

Nail fungal infections can also distort the shape of the nail.

Photo: Randen Pederson

What are the treatments for nail psoriasis and fungus?

Nail psoriasis and fungus have different treatments.

Treatment for nail psoriasis may include:

  • Topical corticosteroids: These are creams, gels, or ointments that contain corticosteroids. You apply them directly to the affected nails to help reduce inflammation and itchiness.
  • Vitamin D analogs: These are synthetic forms of vitamin D, such as calcipotriol (Calcitrene), which can help treat buildup under the nails.
  • Retinoids: Derived from vitamin A, these medications can help treat buildup under the nails. Examples include tazarotene (Tazorac).
  • Phototherapy: This involves exposing the affected nails to ultraviolet (UV) light. It can help slow the growth of skin cells and reduce inflammation.
  • Biologics: These medications target specific proteins in the immune system involved in the development of psoriasis. Doctors typically administer them by injection or infusion.
  • Corticosteroid injections: Injecting corticosteroids directly into the affected nail bed can help reduce inflammation and promote healing.
  • Systemic immunosuppressants: These medications are taken orally to suppress the immune system, reduce inflammation, and slow down the growth of skin cells. Examples include methotrexate (Jylamvo).

Learn 8 ways to manage your psoriasis in style.

Treatment for nail fungus may include Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source :

  • Topical antifungal medications: These medications can be applied directly to the nails to kill the fungus. They are available in various forms, such as creams, lotions, and nail lacquers.
  • Oral antifungal medications: These medications are taken orally and are typically prescribed for more severe cases of nail fungus. However, oral antifungals can also cause severe side effects, such as liver toxicity Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source . Ask your doctor whether oral antifungal medications may work for you.
  • Nail removal: In some cases, the infected nail may need to be surgically removed. This  allows for proper treatment of the underlying fungal infection.

Learn more about top treatments for toenail fungus.

When should I see a doctor?

Contact your doctor if you notice new or worsening signs and symptoms, such as:

  • change in nail appearance, such as pitting, discoloration, or deformity
  • brittle or cracking nails
  • foul odor from the nail
  • pain or discomfort around the nail area
  • difficulty with daily activities, such as gripping or typing

How do doctors diagnose nail psoriasis and fungus?

To diagnose nail psoriasis and fungus, your doctor may:

  • perform a physical examination
  • assess your medical history
  • order laboratory tests

During a physical examination, your doctor will examine your nails for signs of psoriasis or fungus. These can include pitting, discoloration, and thickening. They will then take your medical history and ask questions about your symptoms.

To confirm a nail fungus diagnosis, your doctor may take Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source a sample of the affected nail. They will then use this to perform a fungal culture or potassium hydroxide test.

In some cases, a doctor may also perform Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source a biopsy. This involves taking a small sample of the affected nail or the underlying tissue for examination under a microscope.

What are the risk factors for nail psoriasis and fungus?

Some of the risk factors for nail psoriasis include Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source :

  • a family history of psoriasis or other autoimmune conditions
  • a personal history of other forms of psoriasis, such as psoriatic arthritis
  • stress
  • smoking 
  • seasonal changes
  • certain medications, such as beta-blockers
  • excessive sun exposure

Risk factors for nail fungus include:

  • being an older adult
  • having diabetes 
  • having poor blood flow Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source
  • wearing tight or poorly ventilated shoes
  • walking barefoot in public areas, such as swimming pools or showers
  • having a history of athlete’s foot or other fungal infections 
  • experiencing injury to the nails 
  • having a weakened immune system 
  • living or working in warm and moist environments 
  • sweating a lot

Can I prevent nail psoriasis and fungus?

It may not always be possible to prevent nail psoriasis. However, steps you can take to reduce your risk or manage flare-ups include:

  • Managing stress: Stress can trigger psoriasis symptoms. Finding ways to manage stress may help prevent it from developing or worsening. Techniques can include exercise, meditation, and therapy.
  • Avoiding injury: Injury to the nails can trigger psoriasis symptoms. Because of this, it’s important to take care during activities that could cause nail injuries. These can include while handling sharp objects or participating in sports.
  • Moisturizing: Keeping the nails and surrounding skin moisturized may help Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source prevent dryness and cracking, which can exacerbate psoriasis symptoms.

You may be able to prevent a fungal nail infection by:

  • Keeping your nails clean and dry: Fungi thrive in warm, moist environments. As a result, be sure to dry your feet and hands Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source thoroughly after showering or swimming.
  • Wearing breathable shoes: Tight-fitting shoes and socks made of non-breathable materials can create a warm, moist environment. This may be ideal for fungal growth.
  • Avoiding sharing personal items: Fungal infections can be spread through sharing personal items such as nail clippers, towels, or shoes.

Summary

Nail psoriasis and fungus are two common conditions that can affect the nails. While they may have similar features, they are different conditions that require different management approaches.

Contact your doctor if you have symptoms of nail psoriasis or fungus. They can provide an accurate diagnosis and help you determine the most appropriate treatment.

Was this helpful?
0
Medical Reviewer: Joan Paul, MD, MPH, DTMH
Last Review Date: 2023 May 22
View All Psoriasis Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.