Psoriasis vs. Ringworm: Similarities and Differences

Although psoriasis and ringworm change how your skin looks, they develop for different reasons and need unique treatments. 

Condition Types

Psoriasis: Psoriasis happens when your immune system mistakenly attacks your body, making your skin cells grow too quickly. Extra cells build up on your skin to form thick patches or plaques. Psoriasis isn’t contagious and often runs in families.

Ringworm: This is a fungal infection, not a real worm. It happens when dermatophytes, a type of fungus, infect your skin. The fungus grows best in warm, damp places and feeds on keratin, a protein that makes up your skin, hair, and nails. Ringworm is contagious, and you can catch it from:

• People (skin-to-skin contact)
• Pets
• Shared towels or linens
• Soil
• Surfaces like gym equipment

Durations

Psoriasis: It is chronic (long-lasting). It often comes back, requiring long-term care.

Ringworm: It is usually temporary and goes away in 2-4 weeks with antifungal medicine. It doesn’t usually come back unless you get the fungus again.

Treatment

Psoriasis: At home, you can try Epsom salt, oatmeal, and bleach baths, as well as over-the-counter (OTC) Cortizone-10 (hydrocortisone 1%) to soothe psoriasis symptoms. Providers may also recommend:

• Immune-suppressing medications 
• Phototherapy (light therapy)
• Steroid creams
• Vitamin D ointment

Ringworm: For mild cases, treatment usually starts with an OTC antifungal cream, spray, or powder. Options include:

• Lotrimin AF (clotrimazole)
• Nizoral (ketoconazole) 
• Micatin (miconazole)
• Tinactin (tolnaftate)
• Lamisil AT (terbinafine) 

If ringworm is widespread or doesn’t improve, your provider may prescribe stronger antifungal creams or pills, such as Diflucan (fluconazole), Gris-PEG (griseofulvin), Lamisil (terbinafine), or Sporanox (itraconazole).

Prevention

Psoriasis: You can’t prevent it, but you can reduce flare-ups if you:

• Manage your stress
• Avoid skin injuries
• Follow your treatment plan
• Use gentle skincare products

Ringworm: Unlike psoriasis, you can prevent ringworm if you:

• Avoid skin contact with people or pets who have ringworm
• Don’t share towels, clothing, or combs
• Finish all antifungal treatments, even if the rash looks better
• Keep your skin clean and dry
• Wash clothes and bedding in hot water to kill the fungus
• Wear loose, breathable clothes

Psoriasis and ringworm are different conditions. However, they share some features that can make them easy to confuse. 

Diagnostic Tests

If the diagnosis isn’t clear with a visual exam, your provider may take a skin scraping or biopsy. A lab can check for ringworm by looking at the skin scraping under a microscope and using a special solution to highlight fungal elements. A biopsy can reveal signs of psoriasis.

These tests also help rule out other causes and guide the proper treatment.

Misdiagnosis

Psoriasis and ringworm can look like each other or other skin problems, such as eczema or impetigo. They can also appear on similar body parts, such as your arms, legs, trunk, or scalp, and cause nail changes. This can lead to misdiagnosis, especially early on.

Ringworm can be even harder to recognize if you’ve used steroid creams, since they can change how the rash looks.

You can have both psoriasis and ringworm at the same time. This is more likely if you take immune-suppressing medications for psoriasis, which make it harder for your body to fight infections. If you have both, your provider will usually treat the ringworm first, as steroid creams for psoriasis can hide or worsen a fungal infection.

If your rash isn’t getting better, reach out to a healthcare provider. This is especially true if you notice the rash:

• Doesn’t improve with OTC treatments
• Starts to spread
• Feels painful or tender
• Causes hair loss in the area
• Affects your nails or joints

A primary care provider can diagnose and treat ringworm. If the rash doesn’t go away or worsens, you may need to see a dermatologist, a doctor specializing in skin, hair, and nail conditions. If you have joint pain, your provider may refer you to a rheumatologist. These specialists focus on conditions that affect your joints, immune system, and inflammation.

Psoriasis and ringworm are skin conditions that can look alike and often affect the same areas of the body, making them easy to confuse. However, they have different causes and treatments.

Psoriasis is a chronic autoimmune condition, while ringworm is a contagious fungal infection. If you’re unsure what’s causing your symptoms, a healthcare provider can help you get the correct diagnosis and treatment plan.