Nail Psoriasis vs. Fungus: What Are the Differences?

About 10% to 15% of dermatology visits are made to address nail problems. The appearance of your nails can change because of infections, medical problems, and body changes, but fungus and psoriasis are two of the more common causes.

It may be difficult for you to tell these two conditions apart, but there are several features that distinguish nail psoriasis from nail fungus. In this article, you will learn the differences between the two, the causes of each, and how each condition can be treated.

A dermatologist examines a toenail affected by a fungus.

Alona Siniehina / Getty Images

Is It a Nail Fungus or Nail Psoriasis?

Nail fungus and psoriasis can be difficult to tell apart, with both causing changes in the texture and color of your nails. Telling the two apart might be a little easier once you understand how different these conditions are.

What Is Nail Psoriasis?

Psoriasis is a chronic inflammatory condition that can affect your nails, skin, hair, and joints. The dry, red plaques that often appear on the skin with psoriasis are the most notorious symptom of this immune-mediated disease, but about 80% to 90% of people with psoriasis will experience nail changes at least once during their lifetime.

Known as ungual psoriasis, nail psoriasis can develop with traditional psoriasis as well as with psoriatic arthritis, an autoimmune disease affecting your joints and oftentimes your skin and nails. This problem has also been known to develop in people with a type of inflammation in the tendons or ligaments called enthesitis, and with skin or nail changes that occur after an injury, known as Köebner's phenomenon.

What Is Nail Fungus?

"Nail fungus" is a generic term that can be used to describe any type of fungal growth or infection of the nails. It's the most common diagnosis made for nail problems and accounts for about half of all cases. Anyone can develop a nail fungus, but there are certain situations or conditions that can increase your risk.

Symptoms 

The clinical signs of nail fungus and nail psoriasis are very similar. They both can appear with changes in nail texture and color, as well as structural problems of the nail bed. Your healthcare provider or dermatologist is usually best at detecting the subtle differences that set these two conditions apart.

It's also possible to have both of these conditions at the same time. In fact, some types of nail fungus are particularly common in people with nail psoriasis and appear in about 10% of people with nail psoriasis. The weakening or splitting of the nails with psoriasis makes it easier for organisms to enter and colonize the nail bed.

What's the Same? What's Different?

Nail psoriasis and nail fungus share some symptoms. The most common shared symptoms and what they look like are described below:

  • Pitting: Nail pitting is a classic sign of psoriasis. This is a change in the surface texture of the nail, with small indentations or pits forming across the surface of your nail. The number of pits on a nail can range from one to dozens.
  • Subungual hyperkeratosis: This develops when a chalky white substance—an abundance of keratin—builds up under your nail beds. This buildup eventually raises the nail bed, causing tenderness or pain when pressed on or while you wear shoes. It can make your nails look white, yellow, and thickened, or give the appearance of white patches on your nails. This symptom is most common on the toenails.
  • Onycholysis: Onycholysis is when your nail starts to separate from the nail bed, creating a gap under the nail. When this gap forms, bacteria like pseudomonas can start to grow, creating a dark green color that is often mistaken for melanoma.

There are also some hallmark symptoms of each condition that they don't share.

For nail psoriasis, this includes:

  • Redness around areas of onycholysis
  • A rough nail surface
  • Crumbling of the nail
  • White lines that appear in your nail (leukonychia)
  • Red or brown streaks in your nail (splinter hemorrhage)
  • Patches of yellow or orange coloring under the nail (salmon patches)
  • Thinning of the nail
  • Grooves on the surface of your nail

For nail fungus, symptoms to expect include:

Causes 

While symptoms and clinical signs of both of these nail conditions share several similarities, their causes are very different.

Nail Psoriasis

The exact cause of nail psoriasis, or psoriasis at all for that matter, isn't clear. This chronic, autoimmune condition is believed to develop from one or more of the following factors:

  • Genetics
  • Environment
  • Immunological problems

Many people who have plaque psoriasis will have nail psoriasis at some point during the course of their disease, and it's most common in people with psoriatic arthritis. For some people, it can even appear as a standalone symptom, without any signs of psoriasis on other parts of the body.

Nail Fungus

Nail fungus is not a chronic condition, but severe fungal infections can be difficult to clear completely. Fungal infections of the nail are caused by microscopic organisms that can include molds or yeasts.

Some of the most common fungi identified in nail infections include:

  • Trichophyton rubrum
  • Trichophyton mentagrophytes
  • Trichophyton verrucosum
  • Candida albicans
  • Candida non-albicans
  • Scopulariopsis brevicaulis
  • Aspergilus niger 
  • Rhodotorula mucilaginosa

Risk Factors for Nail Problems

Anyone can develop a fungal nail infection, but nail fungus is most common in people with weakened immune systems or who have:

Psoriasis can be inherited, so you may be at risk if this condition runs in your family. Other possible risk factors for psoriasis, as well as triggers for flare-ups, include:

Diagnosis

Your dermatologist or other healthcare provider may make a diagnosis on a visual inspection of your skin alone, but there are additional tests that might be used to confirm the cause of your nail problem.

Nail Psoriasis 

Testing of your nail through biopsy (removing a sample to be analyzed in a lab) or by analyzing nail clippings can help confirm a psoriasis diagnosis. Your healthcare provider will also examine other areas of your body for additional plaques or lesions, too. In some cases, dermoscopy, a close-up examination with a lighted tool called a dermatoscope, may also be used.

Nail Fungus

In order to confirm nail fungus or the specific organism causing a fungal infection, your provider may take a scraping or nail sample for testing. Lab tests of the skin or nail particles can be used to pinpoint the exact fungi causing the problem and help guide treatment.

Treatment

Because nail psoriasis is a chronic condition and nail fungus is an infection, treatment strategies are very different for these two conditions.

Nail Psoriasis

How your nail psoriasis is treated will depend on the severity of the problem, and where else you may have psoriasis.

For mild or limited cases of nail psoriasis, topical treatments are usually used, including:

In more severe or widespread cases, treatment may include injected or oral medications and other treatments like:

Nail Fungus

Both skin and nail fungal infections are usually treated with the same medications. An antifungal medicine is used to kill the fungi causing the problem, or in some cases slow the growth. The antifungal used to treat your nail fungus may be used for a variety of organism types, or it may be tailored to a specific organism if the exact cause of the growth is identified.

Since nail fungus can be difficult to treat, your doctor may even prescribe an oral antifungal medication. Even with treatment, these fungal infections can take several months or more to resolve completely.

When to See A Healthcare Provider

Managing psoriasis requires ongoing treatment, so working with a dermatologist to control your condition is helpful.

When it comes to nail fungus, you may try to treat it on your own, but prescription-strength formulas and treatments can help keep fungi from growing out of control.

With either condition, it helps to seek treatment early, before pain and tenderness or nail damage occurs.

Prevention 

The prevention strategies for nail psoriasis and nail fungus are different because their causes are different.

Nail Psoriasis 

Since nail psoriasis can be inherited, there may not be anything you can do to prevent it. However, avoiding certain chemicals or environmental pollutants may help. It's also helpful to have good control over your psoriasis in general. Systemic medications like biologics or methotrexate can help you keep psoriasis in check throughout your body, including on your nails.

Nail Fungus

When it comes to fungal infections, keeping the affected area dry and clean is an essential prevention strategy. Specifically, the Centers for Disease Control and Prevention (CDC) suggests taking the following measures to prevent nail fungus:

  • Keep your hands and feet clean and dry.
  • Keep your fingernails and toenails clipped short.
  • Avoid walking barefoot in areas like locker rooms and public showers.
  • Don't share nail clippers with anyone else.
  • If you have manicures or pedicures, be sure the facility is clean and licensed by your state cosmetology board.

Summary

Both nail psoriasis and nail fungus can make your nails thicken, detach from the nail bed, or change color. Psoriasis can develop from a number of causes, but yeasts and molds lead to fungal nail infections. Keeping your nails clean and short, and managing your overall health can help prevent both of these conditions.

A Word From Verywell

If you have psoriasis, there's a chance you will develop symptoms of the condition on your nails at some point in your life. It can also make you more prone to fungal infections of the nail. Nail fungus also will develop on its own, especially in people with weak immune systems or whose hands and feet are often wet or uncared for.

If you have discoloration, cracking, or tenderness on your finger or toenails, your healthcare provider can help you identify the exact cause in order to identify the most effective treatment.

Frequently Asked Questions

  • Are nail psoriasis and fungus contagious?

    Psoriasis is not contagious, but some types of fungal infections can be shared with others. It's important to not share nail clippers or other hygiene products with others. You should also avoid walking barefoot in locker rooms and other wet, public places.

  • Is there a cure for nail psoriasis?

    Psoriasis cannot be cured, but there are a number of treatments that can help control the condition to reduce symptoms.

  • How can you get rid of nail psoriasis?

    There are topical (applied directly to the nail) and systemic (work throughout the body) treatments that can help reduce your symptoms of nail psoriasis, but you may not be able to get rid of the condition completely.

  • Why do you get nail fungus?

    Nail fungus often develops when you've picked up a type of fungi in a contaminated area, or molds and yeasts colonize on moist areas. Keeping your hands and feet clean and dry and your nails short can help prevent nail fungus.

  • Can you get gel nails with psoriasis or fungus?

    It's generally not a good idea to get gel manicures over damaged nails. While gel nails can cover the appearance of nail fungus or nail psoriasis, gel manicures can be damaging to your nails on their own. Placing gels over a damaged nail can increase the problems you are already experiencing on your nails.


11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Haneke E. Differential diagnosis of nail psoriasis and nail onychomycoses: A report based on 40 years of specialised nail consultations. EMJ Dermatol. August 2020. doi:10.33590/emjdermatol/20-00008.

  2. Muneer H, Masood S. Psoriasis of the nails. May 2022. StatPearls.

  3. Kyriakou A, et al. Fungal infections and nail psoriasis: An update. J Fungi. February 2022;8(2):154. doi:10.3390/jof8020154.

  4. Chaowattanapanit S, Pattanaprichakul P, Leeyaphan C, Chaiwanon O, Sitthinamsuwan P, Kobwanthanakun W, Hanamornroongruang S, Bunyaratavej S. Coexistence of fungal infections in psoriatic nails and their correlation with severity of nail psoriasis. Indian Dermatol Online J. September-October 2018;9(5):314-317. doi: 10.4103/idoj.IDOJ_192_17.

  5. The Psoriasis and Psoriatic Arthritis Alliance. Psoriasis in the nails.

  6. Piraccini BM, Starace M. Optimal management of nail disease in patients with psoriasis. Psoriasis. 2015;5:25-33. doi:10.2147/PTT.S55338.

  7. American Academy of Dermatology Association. What is nail psoriasis and how can I treat it?.

  8. American Academy of Dermatology Association. Nail fungus: Signs and symptoms.

  9. Centers for Disease Control and Prevention. Fungal nail infections.

  10. Kamiya K, Kishimoto M, Sugai J, Komine M, Ohtsuki M. Risk factors for the development of psoriasis. Int J Mol Sci. September 2019;20(18):4347. doi:10.3390/ijms20184347.

  11. American Academy of Dermatology Association. Gel manicures: Tips for healthy nails.

By Rachael Zimlich, BSN, RN
 Rachael is a freelance healthcare writer and critical care nurse based near Cleveland, Ohio.