How to identify psoriasis and ringworm
Psoriasis and ringworm are very different conditions. Ringworm is a fungal infection that will go away with treatment. Psoriasis is a chronic autoimmune condition that comes and goes throughout a person's life.
When someone develops a rash, they may find it difficult to work out what caused it. A doctor can examine or order tests to determine which condition they have.
In this article, we look at the differences between ringworm and psoriasis and compare them with other conditions that can cause similar rashes.
Psoriasis vs. ringworm
Ringworm, pictured here, is often circular. The shape of psoriasis may be less regular.
Both psoriasis and ringworm can cause red, scaly patches to appear anywhere on the body. Both can also lead to intense itching.
A person who has never had ringworm before or is having their first psoriasis flare may not know which condition they have.
Psoriasis is an autoimmune condition. It causes red, scaly plaques that may have a gray hue or peel. During a psoriasis flare, a person develops scaly, red, irritated patches of skin because of the skin's rapid shedding.
Ringworm causes a red, circular, and often scaly rash. Ringworm is highly contagious, spreading quickly through contact with another person who has the condition.
A fungal infection causes ringworm. Despite its name, it has nothing to do with worms.
Both psoriasis and ringworm can develop in similar places. One type of psoriasis called inverse psoriasis can affect the area around the groin. When ringworm affects the groin area, it is called jock itch.
Psoriasis often affects the scalp. When ringworm affects the scalp, it is called tinea capitis.
Some important distinctions between psoriasis and ringworm include:
The shape of the rash
Ringworm is often circular. It typically begins as a rash with a clearly defined border that looks like there is a worm under the skin. The center of the rash appears sunken and may be gray or scaly.
While psoriasis rashes can also be round, the shape is less regular and does not resemble a worm.
Rash risk factors
People develop ringworm after coming into contact with someone else who has the infection. Children, anyone in close contact with children, and people who come into contact with others, such as at the gym, are more likely to get the infection.
Psoriasis is not contagious and can affect anyone.
Psoriasis plaques may spread, appearing on one area of the body and then another.
Ringworm grows larger over several days and can spread to other areas of the body.
Changes in the rash
Unlike ringworm, psoriasis plaques can change in color and texture. They are often red at first and then may become grey and scaly, or crack and bleed.
How the rash feels
Both ringworm and psoriasis rashes are itchy, but the ringworm itch is often more intense. Psoriasis can be painful and may tingle or burn. Some people develop other symptoms with psoriasis, such as a fever or muscle aches.
Psoriasis vs. other skin conditions
Acne begins under the skin but psoriasis is immediately visible on the skin.
Psoriasis can resemble some other skin conditions.
A skin injury can trigger a psoriasis flare. This means that a rash that begins as something else can become psoriasis. For instance, a person who has eczema and psoriasis may find that eczema leads to psoriasis flares.
Some other conditions that may look like psoriasis include:
Acne usually causes well-defined round sores. The bumps can be very small or quite large and may be painful. Acne lesions usually come to a head and then shrink over several days. Psoriasis does not come to a head. While acne begins under the skin, psoriasis is immediately visible on top of the skin.
Eczema is a chronic skin condition that causes dry, scaly patches to form on the skin. The patches sometimes appear after a change in the weather or exposure to something that irritates the skin. Eczema can be itchy and scaly but is not typically gray or silvery like psoriasis.
Sometimes, an infected skin injury can look like psoriasis.
Signs of an infection include:
- intense pain
- yellow pus
- red streaks coming from the injury
- a fever
Sweating or being exposed to high temperatures can lead to a heat rash. For example, a person might develop a heat rash on their legs after sitting in front of a space heater.
The rash is not usually painful and goes away on its own in a few days. In some cases, a person might need to use corticosteroid cream to speed healing.
An allergic reaction can trigger an outbreak of hives. Allergic reactions typically appear suddenly, either because of something that came into contact with the skin or a food allergen.
Allergic reactions can cause other symptoms, too, such as difficulty breathing or feeling sick.
Although psoriasis plaques can look very dry and scaly, dry skin does not cause them. Dry skin can crack open and bleed, and may peel. Unlike psoriasis, dry skin does not change color or shape.
Some types of psoriasis, including guttate psoriasis, look like tiny blisters. A blister due to skin irritation, such as from a shoe rubbing the foot, typically develops over several days, then bursts and goes away. If the blisters do not go away or are spreading, it could be psoriasis or another skin disorder.
When to see a doctor
A person should consult a doctor if their rash is getting worse.
Both psoriasis and ringworm need medical treatment. People should see a doctor if they suspect they have either condition.
People should also see their doctor if:
- The rash is getting worse, and treatment for psoriasis or ringworm does not help.
- Signs of a skin rash or infection develop in someone with a chronic illness or weakened immune system.
- A fever, chills, or muscle aches develop along with a skin rash.
- A skin rash covers much of the body.
- There are signs of an allergic reaction, such as a worsening rash, vomiting, difficulty breathing, or feeling sick.
- A rash, skin irritation, or fever develops following a skin injury.
Treating psoriasis and ringworm
Doctors can treat ringworm using antifungal creams or oral antifungal medication. With the correct treatment, ringworm usually goes away within 2 to 4 weeks.
People with low immunity or debilitating conditions may develop severe infections due to ringworm. To prevent the infection from getting worse, they may need more aggressive treatment.
Psoriasis is a chronic condition. Flares come and go over time. There is no cure, though people can manage their symptoms using creams, medications, or light therapy. They can also reduce the risk of flares by avoiding triggers, such as stress or drinking alcohol.
Psoriasis and ringworm are two possible causes of a red, scaly rash. If someone cannot tell the difference at home, they should speak to a doctor for an accurate diagnosis and effective treatment plan.
Prompt treatment can help, even when the rash is due to a chronic condition, such as psoriasis. It is essential that people seek help as many skin rashes look alike and it is vital to receive the correct treatment.
Doctors can prescribe antifungal medications to treat ringworm. Some rashes, especially those due to psoriasis, may need several types of treatment.
Finding the right combination of treatments can be difficult at first. A skilled and compassionate dermatologist can help people find treatment options that suit their lifestyle and improve their skin.