Psoriasis vs. tinea versicolor

If you notice small red spots on your skin, you might be wondering what’s going on. Maybe the spots just appeared and they itch, or they may seem to be spreading.

A rash with small, red spots could signal two pretty common conditions, but only a doctor can make a diagnosis. These conditions are psoriasis and tinea versicolor (TV). The symptoms of these conditions can be similar, but the causes, risk factors, and treatments are different.

Causes and risk factors

Psoriasis is a chronic autoimmune disorder. It is not contagious. While the exact cause is unknown, you are more likely to develop it if someone in your family has it. People with HIV, and children who have recurring infections like strep throat, are also at a higher risk. Other risk factors include long-term smoking, obesity, and stress.

TV is a fungal condition caused by an overgrowth of yeast. Everyone has some amount of yeast living on their skin. But you won’t notice it unless the yeast grows out of control and gives you a rash.

Anyone can get this common condition. But symptoms may look different depending on your skin tone. Exposure to high heat and humidity puts you at higher risk for TV. People who live in tropical areas are more likely to develop it than those in cooler or drier climates, according to the American Academy of Dermatology. Excessive sweating, oily skin, and recent topical steroid use also increase risk.

TV is not contagious, which makes it different from other fungal infections, such as ringworm, which spreads through direct contact and is associated with poor hygiene habits.

Symptoms

There are different types of psoriasis. Plaque psoriasis is the most common type. It can be identified by its raised, reddish skin patches. These patches are called plaques. Plaques can appear all over the body or in certain places like elbows or knees.

Guttate psoriasis is another type of psoriasis. This type is most likely to be mistaken for TV. Guttate psoriasis is characterized by small, red spots that can show up on places including:

  • arms
  • legs
  • trunk
  • face

People with TV also develop small, red spots on their body. According to Dr. Fil Kabigting, an assistant professor of dermatology at Columbia University Medical Center, a TV rash usually appears on the chest, back, and arms. It’s more likely to show up in warmer months, and it may look different depending on your skin tone.

If you have fair skin, the rash may appear pink or tan, and slightly raised and scaly. If your skin is darker, the rash may be tan or pale, said Kabigting. The TV rash is also itchy and can cause skin discoloration. TV can leave behind dark or light spots even after successful treatment. These spots can take months to clear.

What’s the best way to determine whether you’ve got psoriasis or TV? According to Kabigting, there are some key differences:

  • TV will likely itch more than psoriasis.
  • If your rash is on your scalp, elbows, or knees, it could be psoriasis.
  • Psoriasis scales will become thicker over time. A TV rash will not.

Treatment

If you have psoriasis, your doctor will help to determine the best treatment. You may have to try different treatments, or combine multiple treatments.

Possible treatments include:

  • corticosteroids
  • oral medications
  • biologic injections
  • UV-light therapy

There is currently no cure for psoriasis. The goal of most treatments is to control your symptoms and reduce outbreaks.

With TV, antifungal medications clear up most infections. According to Kabigting, most mild cases respond to antifungal shampoos and creams. An oral antifungal medication might be considered in severe cases. To help prevent the yeast infection from coming back, avoid excessive heat and sweating and practice good hygiene.

When to see a doctor

If your symptoms bother you or they get worse, call your doctor. A dermatologist can diagnose your skin problems and get you the right treatment.

If you have TV, it’s important to seek help right away. “Patients typically delay coming into the office, and present only after the rash has spread or become severely discolored,” said Kabigting. “At that point, the rash and the associated discoloration are much more difficult to treat.”