Why Psoriasis Is Not Contagious

Understanding the causes of the autoimmune skin condition

Psoriasis is not contagious. It is an autoimmune disorder that cannot be spread from person to person. You cannot get it by touching a skin patch (called a plaque) of someone with psoriasis. It is not an infection you can "catch."

With that said, there are skin conditions that mimic those of psoriasis which may be contagious. If you have symptoms of psoriasis but have not been diagnosed, it is in your best interest to see a dermatologist.

This article explains the cause and symptoms of psoriasis, including how autoimmune diseases work. It also compares psoriasis with other skin conditions with similar symptoms.


6 Myths About Psoriasis

Cause of Psoriasis

The cause of psoriasis is not well understood, although it is thought that genetics, environment, and prior skin infections all contribute to the onset of the disease.

Psoriasis is a chronic (long-lasting) inflammatory autoimmune disease. Autoimmune diseases are those in which the immune system attacks the body's own cells and tissues in the same way it might attack a harmful virus or bacteria. Inflammation, the body's natural response to harmful agents, is characteristic of all autoimmune diseases.

With psoriasis, the immune system targets cells of the epidermis (the outermost layer of skin cells) called keratinocytes. The inflammatory response causes keratinocytes to grow rapidly—from the usual 28 to 30 days to a mere 3 to 5 days. This causes keratinocytes to "pile up" on the surface of the skin, leading to itchy, scaly patches known as plaques.

People sometimes assume that psoriasis is contagious because it can run in families. And, while a family history of psoriasis is a risk factor for the disease, family members do not "catch" it from each other. Family genetics is ultimately the culprit.

Autoimmune disorders are not contagious. They are caused by a malfunctioning immune system rather than an infectious disease you can catch.

Some contagious infections, like strep throat, can cause psoriasis to flare up. These infections don't "cause" psoriasis but simply trigger symptoms if you have the disease.

Other triggers include:

  • Stress
  • Smoking
  • Hormonal changes (such as during menopause or menstruation)
  • Medications (like lithium and ACE inhibitors)
  • Excessive alcohol use

By reducing stress and avoiding triggers like cigarettes and alcohol, you may be able to reduce your risk of flare-ups. Even if symptoms do return, it's important to remember that there is no "fault" to having psoriasis or "blame" to shoulder.

Two women talking at cafe

Symptoms of Psoriasis

The most common type of psoriasis, called plaque psoriasis, accounts for 90% of cases and is recognized by the classic symptoms of the disease. But, there are other types that cause different symptoms and/or affect specific parts of the body. They all involve lesions, but not necessarily the scaly, raised patches we recognize as plaques.

These variations can lead people to assume that some other disease is involved.

Here is a breakdown of symptoms of the most common psoriasis types:

Type Symptoms Location
Plaque psoriasis Raised areas of inflamed skin covered with silvery-white, scaly skin, often with itchiness and bleeding from scratching Most commonly on the elbows, knees, scalp, and back
Pustular psoriasis Raised bumps filled with non-infectious pus Either widespread or localized to the palms of the hands or soles of the feet
Inverse psoriasis Smooth, inflamed patches of skin Mostly in skin folds such as around the groin, armpits, and genital under the breasts, or between the buttocks
Guttate psoriasis Clusters of small scaly, pinkish, droplet-like lesions Primarily the trunk but also the limbs and scalp
Napkin psoriasis A subtype affecting infants The diaper region
Psoriatic onychodystrophy A complication of all psoriasis types that causes the pitting and whitening of the nails Fingernails and toenails

Conditions That Mimic Psoriasis

Because of its wide variation in appearance, psoriasis is often mistaken for other skin conditions, some of which may be contagious.

These include:

Condition Symptoms Can Look Like Contagious?
Contact dermatitis A localized skin reaction that causes redness, itching, swelling, and rash as well as cracking and scaling Plaque psoriasis No
Eczema (atopic dermatitis) Dry, cracked patches of skin with itchiness, rash, and bleeding from scratching Plaque psoriasis No
Folliculitis Clusters of small bumps or pus-filled pimples around hair follicles, often on the face, arms, back, and legs Pustular psoriasis, guttate psoriasis No
Genital herpes An outbreak of painful blisters on the genitals, groin, or anus Pustular psoriasis, guttate psoriasis (in the early stages) Yes
Herpes zoster (shingles) Clusters of painful blisters limited to one side of the body Pustular psoriasis, guttate psoriasis (in the early stages) No
Impetigo A red, itchy sore that crusts over into a honey-colored scab, especially around the nose and mouth Plaque psoriasis, guttate psoriasis (in the early stages) Yes
Molluscum Raised, round, skin-colored bumps, often on the face, neck, arms, legs, abdomen, and groin Guttate psoriasis Yes
Napkin dermatitis (diaper rash) Inflamed skin in the diaper area, sometimes with peeling flaking Napkin psoriasis No
Onychomycosis (nail fungus) Nail pitting, discoloration, flaking, and nail loss Psoriatic onychodystrophy Yes
Scabies A mite infestation that causes an intensely speckled rash, mostly in skin folds and around the waist Plaque psoriasis, inverse psoriasis Yes
Squamous cell carcinoma A type of skin cancer mostly found on sun-exposed skin that causes a rough, reddish scaly patch Plaque psoriasis No
Staphylococcus aureus A bacterial infection that can cause swelling and pain, and an open sore and, in some cases, rash on your palms and soles Plaque psoriasis, pustular psoriasis Yes
Tinea cruris (jock itch) A fungal infection that causes a reddened area of skin in the crease of the groin, sometimes with little blisters Inverse psoriasis Yes
Tinea pedis (athlete's foot) A fungal infection that causes scaly, peeling, or cracked skin between the toes, as well as toenail damage Plaque psoriasis, pustular psoriasis, psoriatic onychodystrophy Yes
Tinea versicolor A fungal infection that patches of skin discoloration with scaling, usually on the back, chest, neck, and upper arms Plaque psoriasis, guttate psoriasis No

Diagnosing Psoriasis

If you have any of the above symptoms, contact your healthcare provider. They can evaluate your condition to determine if it is psoriasis or if it's another condition that may or may not be contagious.

Although the signs and symptoms of psoriasis are often "classic," a dermatologist will still want to conduct tests to ensure some other disease is not involved. The tests will typically involve:

  • A physical examination
  • A review of your medical history and family history
  • A skin biopsy
  • A nail scraping or biopsy

Other tests would be ordered if other conditions are suspected.

5 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. American Academy of Dermatology. Psoriasis: causes.

  2. Boehncke WH, Schon MP. Psoriasis. Lancet Dermatol. 2015 Sep;386(9997):983-94. doi:10.1016/S0140-6736(14)61909-7

  3. Huang YH, Kuo CK, Huang LH, Hsieh MY. Familial aggregation of psoriasis and co-aggregation of autoimmune diseases in affected families. J Clin Med. 2019 Jan;8(1):115. doi:10.3390/jcm8010115

  4. National Health Service (UK). Causes - psoriasis.

  5. Raychaudhuri SK, Maverakis E, Raychaudhuri SP. Diagnosis and classification of psoriasis. Autoimmunity Rev. 2014 Jan:13(4–5):490–5. doi:10.1016/j.autrev.2014.01.008

By Ruth Jessen Hickman, MD
Ruth Jessen Hickman, MD, is a freelance medical and health writer and published book author.