What Conditions Can Be Misdiagnosed as Psoriasis?

Medically reviewed by Debra Sullivan, PhD, MSN, CNE, COI on November 16, 2016Written by Ashley Marcin on January 13, 2016

Understanding the basics

When you have ongoing skin irritation, getting the correct diagnosis as soon as possible is key. Psoriasis is a lifelong condition, but it can be managed with the right treatment plan. Because psoriasis shares characteristics with other skin conditions, a doctor might not always identify it when they first perform an examination.

Here’s more about psoriasis, its symptoms, and what to do if you think you’ve been misdiagnosed.

What is psoriasis?

Psoriasis is the most common autoimmune disease in the United States. Ten percent of the population inherits at least one gene that creates a predisposition for having psoriasis. Approximately 6.7 million people in the United States have the disease. And it affects 2 to 3 percent of the world’s population.

Psoriasis typically begins to appear between ages 15 and 35, but it can start at any age. Many people may carry the gene for psoriasis, but it doesn’t always express itself. Instead, different triggers can bring about the symptoms quite unexpectedly. The triggers can include:

  • stress
  • injuries
  • medications
  • infections
  • diet

What are the symptoms of psoriasis?

If you have a rash that just won’t go away, don’t simply ignore it. Psoriasis can manifest itself in different ways and in varying severities. It can also affect different parts of your body.

The primary symptoms can include:

  • patches of red skin
  • silvery scales on the skin
  • dry skin
  • cracked skin
  • bleeding skin
  • itching
  • soreness
  • pitted nails
  • thick nails
  • stiff joints
  • inflamed joints

You could find a small spot or two of irritation or a very large area on your body might be affected. Beyond basic symptoms, it’s important to note that there are many types of psoriasis:

Plaque psoriasis

Plaque psoriasis is the most common of all types. You’ll experience the general symptoms on different parts of your body. You may even notice patches inside your mouth and nose.

Nail psoriasis

Nail psoriasis affects the fingernails and toenails. They may get loose or even fall off with time.

Scalp psoriasis

Scalp psoriasis is also localized. The scales reach beyond your hairline. You may notice dead, flaky skin after itching your scalp.

Guttate psoriasis

Guttate psoriasis can happen after bacterial illnesses, such as strep throat, and it usually affects children and young adults. The sores you’ll find with this type are shaped like water drops and are concentrated on the:

  • arms
  • legs
  • scalp
  • trunk

Inverse psoriasis

Inverse psoriasis can be caused by fungal infections. It creates areas of smooth, red rash, especially:

  • under the armpits
  • around the breasts
  • around the groin
  • on the genitals

Pustular psoriasis

Pustular psoriasis is uncommon, but it may give you more than just skin symptoms. You’ll typically get a fever, chills, and diarrhea with the red rash. Blisters filled with pus accompany the patches or irritation.

Erythrodermic psoriasis

Erythrodermic psoriasis is the least common type of psoriasis. It causes large areas of your skin to peel, itch, and burn.

How is psoriasis diagnosed?

Your primary care doctor may refer you to a dermatologist for a diagnosis of psoriasis. They’ll likely ask if you have a family history of the disease and ask about different triggers that may have set off your symptoms.

From there, they’ll perform a physical examination that includes a complete skin exam. They’ll look at your skin for signs of psoriasis. In some cases, you may need to undergo a procedure called a skin biopsy. Your doctor will use general anesthetic and obtain a small sample of your skin to study under a microscope. If the sample tests positive, this is enough information to diagnosis you with psoriasis.

What else could this skin condition be?

There are a number of skin conditions that share characteristics with psoriasis. Knowing their symptoms, causes, and other characteristics may help you identify your own skin issues.

Seborrheic dermatitis

If your rash is concentrated on oily parts of your skin, it might be seborrheic dermatitis. With this condition, you’ll experience itchy and scaly skin on your back, upper chest, and face. You can also develop a condition on your scalp that looks like dandruff.

Lichen planus

The immune system is also the main culprit with lichen planus. The lesions you’ll see are flat. These can often form rows on your arms and legs. You may also experience itching or burning. White lines may appear over the irritated areas.

Ringworm

Rashes that have a ring shape might be caused by ringworm or dermatophytosis. This fungal infection affects the top layer of your skin. You can contract the infection through contaminated soil or by close contact with affected people.

Pityriasis rosea

If you have pityriasis rosea, you’ll likely get a single spot in the first stage. This skin condition is common and may eventually take on the appearance of pine branches. You’ll typically notice the rash on your stomach, chest, or back before it spreads.

Psoriasis can also be confused with:

  • atopic dermatitis
  • pityriasis rubra pilaris
  • secondary syphilis
  • tinea corporis
  • tinea capitis
  • cutaneous T-cell lymphoma
  • certain drug reactions

Do you think you’ve been misdiagnosed?

If you’re concerned about being misdiagnosed, make an appointment with your doctor. You may even want to request a skin biopsy so you can get a more definitive diagnosis. While you’re at it, try to think of information that might help with identification.

Ask yourself:

  • Do I have a family history of psoriasis?
  • How long have I noticed symptoms?
  • Where is the affected area located?
  • Are there any triggers that might have produced my symptoms? If so, what are they?
  • Do I have signs that align with any of the look-alike conditions?
  • Are there any other symptoms, like swollen joints, that are bothering me?

If you still aren’t satisfied after your appointment, seek a second opinion. You can ask your primary care doctor for a referral for a dermatologist. A dermatologist is usually your best bet for getting the most accurate diagnosis of a skin condition.

Treatment and complications

Treating psoriasis involves healing the areas of discomfort and slowing skin growth. Depending on your symptoms and the type of psoriasis you have, your doctor may try different topical therapies, like vitamin D or corticosteroids. Phototherapy, also known as ultraviolet light therapy, can also be effective in certain cases. More advanced flare-ups may be treated with medicines like methotrexate, cyclosporine, biologics, or acitretin.

Before prescribing anything, your doctor will consider the severity of your condition, your medical history, and potential drug interactions.

There isn't a cure for psoriasis, but knowing you have it may help you diagnose other health issues. People with psoriasis are at a higher risk of developing other conditions like psoriasis arthritis, metabolic syndrome, and cardiovascular disease.

Learn more: Severe psoriasis: Managing a flare-up »

The bottom line

There are many possible reasons for your skin irritation. If you’re concerned about psoriasis or think you may have been misdiagnosed, be proactive. Your doctor will use all the information you provide to help target your diagnosis and treatment plan. No detail is too silly or insignificant.

Keep reading: 9 psoriasis myths you probably think are true »

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