When I was in high school, I was taking a lifeguarding class so was often in the swimming pool. I started breaking out on my chest with dry, patchy, itchy spots. The nurse panicked, assumed I had something super contagious and wouldn't let me return to school until I was seen by a physician. A few days later I was diagnosed with #Pityriasis Rosea. These rashes last a while so I was quite familiar with it into my clinical practice, but pityriasis versicolor was a bit less familiar.
Let me discuss each of them individually and then compare them, but dermatology in general is tough. This isn't unlike saying, foraging for mushrooms is fun but be sure you have someone knowledgeable with identifying which ones are safe before consuming, because they can be confused. If you aren't super confident and have concerns, please connect with our office or your local dermatologist for confirmation.
The rather easy aspect of diagnosing pityriasis rosea is that it initiates as one, oval spot. Generally this is on the face, sometimes on the chest, and other times it may be on the back, less often on the extremities. This initial patch is called the herald patch and can be quite large, up to about 10 centimeters (big as a newborn's head). More often, and all the ones I have identified, are smaller like half your thumb's length. From there smaller dots will start to appear, sweeping out from the middle of the body, sort of like drooping pine-tree branches. These are dry lesions, so are often itchy.
Pityriasis (pit-ih-RIE-uh-sis) rosea can happen at any age, but it is most common between ten years and thirty-five years. It is self-resolving so time does the trick, but that's to the tune of a couple months or about ten weeks. Treatment can help. Keep in mind these don't scar, so medicated lotions are more for the itching and to speed up healing. Most often though, no medical intervention is necessary. This is not contagious and seldom recurs.
The literature shares that sometimes before that herald patch appears, there may be headache, fatigue, fever or sore throat but I can't say I've seen this in clinical practice. We really don't know why this happens, but because of the aforementioned, it is thought this may be triggered by an infection, particularly a virus - the herpes virus. It isn't related to herpes though, and again, is not contagious.
Another rash that is common, with a similar name, but is not the same is pityriasis versicolor. This one is easily diagnosed in the summer, when getting a tan changes your complexion. Maybe you notice visible white patches on your skin during these times of the year? This one is yeast and is most common on the back, chest, and shoulders.
Aesthetically, this looks similar to other rashes which relate to loss of pigment and it can be somewhat itchy, but not always. Human weather can cause this outbreak, sweating, and sun but that's more because it goes undetected in the winter. Pityriasis versicolor may be white, or pink, or even tan in some clients, but the yeast is what causes the color change as it inhibits normal skin pigmentation.
This yeast is actually found on those with very healthy skin, but it grows a little more abundant in some people, which the literature really doesn't explain. It isn't necessarily contagious because again, you sort of need to be prone to this particular type of yeast, Malassezia. If you have taken steroids, you are a bit more prone, as well as if you suffer with an autoimmune disease.
Diagnosis is made through having a fungal culture, or a scraping of the lesion for confirmation of diagnosis. This can be similar to vitiligo which is why diagnosis through scraping is helpful, but an experienced clinician can often differentiate this through clinical exam only. Many times the powdery scale on the surface is evident.
This condition really is more of a nuisance than anything. Once the yeast is identified, Lamisil is often recommended for smaller lesions. When larger spots are identified, or more stubborn spots, then anti-yeast tablets are often recommended, such as itraconazole for a week. Nizoral or Selsun may be helpful when in the scalp. More natural recommendations can be tried too, and there are a plethora of options here for addressing fungus. Our clients are offered many of these suggestions in our educational forums, particularly our Earth Medicine program, but your clinician should be able to guide you here as well.
A few points of note, this can be a fairly chronic condition for individuals. Even with treatment, this may return and the white spots may not regain their pigmentation again for months, even after all evidence otherwise that the rash has healed. Using an anti-yeast shampoo or body wash can help prevent recurrences (think Tea Tree oil), although Nizoral or Selsun are also commonly recommended. Interestingly, there is theory that Malassezia is more common in people who frequently moisturize their skin.
Discerning the Difference
Often in healthcare when we think pityriasis, we think the rosea type. The latter is often referred to as Tinea Versicolor. One is more patchy and feels dry (rosea) while the other can readily go unnoticed until sun darkens the surrounding skin. One is a yeast (versicolor) and one is not. Neither are contagious. If you need help identifying these or want additional suggestions, don't hesitate to connect with our office.