Sometimes, it can be hard to tell psoriasis apart from other skin conditions like eczema, ringworm, or seborrheic dermatitis. Noticing key differences can help you determine what condition you have.

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If a red, itchy, or scaly rash emerges on your skin, you may naturally wonder whether it’s psoriasis, eczema, or something else.

While a visit to a medical professional for a formal diagnosis is always recommended, you can also narrow down the possibilities by paying attention to different signs and symptoms.

Read on to learn about how to tell psoriasis apart from other common skin conditions.

Psoriasis is an autoimmune condition that often appears on the outer elbows, outer knees, lower back, hands, and scalp.

  • Plaque psoriasis: This is the most common type (about 80% of cases), characterized by thick, silver-scaled plaques.
  • Guttate psoriasis: This form causes large rashes consisting of small scaling pink to salmon-colored bumps.
  • Inverse psoriasis: This causes smooth, red patches of skin that may look raw.
  • Pustular psoriasis: This causes pus-filled bumps.
  • Erythrodermic psoriasis: A severe form of psoriasis with widespread redness, peeling, inflammation, and burning, this can also cause a fever.

Both eczema and psoriasis cause skin discoloration and itching. However, key differences include:

  • Appearance: Psoriasis typically forms thick, silvery scales, while eczema is often characterized by dry, leathery patches.
  • Location: Psoriasis typically appears on the outer elbows and knees, while atopic eczema typically occurs on the inner elbows and knees.
  • Onset: Psoriasis typically emerges later in life. Eczema often starts in childhood.

Both seborrheic dermatitis and eczema can affect the scalp and cause itching and irritation. Differences include:

  • Appearance: Psoriasis forms thick, dry, silvery scales. Seborrheic dermatitis typically produces flaky white or yellowish greasy scales.
  • Location: Psoriasis may appear anywhere on the body, while seborrheic dermatitis pops up in areas with lots of oil, like the scalp.

Both ringworm and psoriasis include discolored scaly patches, but differ in:

  • Appearance: Ringworm typically has a distinct circular shape with unaffected skin in the center (a ring). Psoriasis patches tend to be much more irregular, although somewhat symmetrical.
  • Cause: Ringworm stems from a fungal infection and is contagious. Psoriasis is not contagious and autoimmune factors cause it.

Both pityriasis rosea and psoriasis involve scaly rashes. They differ in:

  • Appearance: Pityriasis rosea lesions are usually scattered in a diffused “Christmas tree” pattern. Psoriasis typically lacks a distinctive pattern, aside from some symmetry.
  • Location: Pityriasis rosea typically emerges on the trunk, upper legs, hips, upper arms, and shoulders. Psoriasis can appear anywhere.
  • Duration: Pityriasis rosea typically clears up in a few weeks to months. Psoriasis is a chronic condition which means it lasts for a long period of time.
  • Causes: While the cause of pityriasis rosea in’t fully understood, it’s thought to be viral in nature, while psoriasis is an autoimmune condition.

Both lichen planus and psoriasis are inflammatory conditions. They have key differences including:

  • Appearance: Most commonly, lichen planus causes bumps that are shiny, firm, and reddish purple. Sometimes the bumps have tiny white lines running through them. Psoriasis forms thicker plaques.
  • Location: Lichen planus can cause swelling and irritation in the mucous membranes, such as the mouth and genitals. However, psoriasis typically doesn’t.
  • Duration: Lichen planus tends to clear on its own over the course of months or years, while psoriasis is a chronic condition.

Less commonly, people may mistake psoriasis for conditions including:

Whether you think you may have psoriasis or another skin condition, it’s a good idea to visit a doctor if you experience:

  • skin changes that last more than a couple of weeks
  • severe itching, pain, or discomfort that interferes with your daily life
  • rapid spreading or worsening of symptoms
  • signs of infection such as intense redness, inflammation, or pus
  • joint pain or swelling in addition to skin changes
  • fever

Although psoriasis has overlapping symptoms with several other skin conditions, understanding a few key differences can help you arrive at the correct diagnosis.

Of course, it’s always best to visit a dermatologist who can formally diagnose your condition and help guide you to the appropriate treatment.

If your skin condition interferes with your daily life, seeking support can help you live more fully and well again.