John is a 16-year-old water polo player who has been working out this summer for the fall season. He plays club water polo and lifts weights three days a week at the local gym. He was brought into the office because of a “bad case of ringworm”. When I entered the examining room, John was sitting in the chair with his T-shirt on his lap. A polite young man, he stood up and gave me a firm handshake. “Well, Doc, I wasn’t able to stay away very long,” he mused. I had completed his sports physical one month earlier. As we exchanged pleasantries, I inspected his torso and made my diagnosis.
John’s mom was sitting next to him with a plastic bag on her lap containing tubes of creams and ointments. “Johnny’s got this really bad case of ringworm, and it won’t go away,” she said with a frustrating voice. “I used some over-the-counter creams with no success. Then I remembered that someone in the family had ringworm last year and it cleared up with a prescription cream. Some of that cream was left over and I even tried that, but it didn’t do a thing”, she went on. “In fact,” she added, “he now has this awful rash on the back and I think it’s an allergic reaction to the cream!”
Before I could ask a question, she looked at John and declared, “I told you that I didn’t like that gym. I’m sure that you picked up the ringworm there.” John looked at me and shrugged his shoulders.
I examined the young man and found a three-inch round, red, and scaly lesion on his right side, just below the armpit. It was lighter in color in the center that gave the appearance of a raised border. On his back, he had a number of salmon-colored, oval lesions that were slightly raised and similar in appearance. There were about 20 of these, each one measuring from 1/4 - 1/2 inch in length. From across the room, one could detect a pattern to these spots on his back. They lined up in an oblique or sweeping distribution away from his spine. Upon close inspection, each lesion had a scaly or flaky center to it. Other than the rash, John’s exam was completely normal.
Looking at his mom I announced, “Don’t cancel John’s membership to the gym just yet.” The boy clenched his fist and let out a big “Yesssss!!!” I could tell that his mom was perplexed and a bit disappointed. “John has a common skin condition known as Pityriasis Rosea.”
Pityriasis Rosea (P.R.) is a benign, common skin condition that occurs in children and young adults. The exact cause of P.R. is not yet known, although a virus has been suggested. John’s case is a classic presentation of P.R. A solitary, round or oval lesion that resembles ringworm usually precedes the generalized eruption of P.R. This is known as a “herald patch”, and it can occur anywhere on the body. Herald patches vary in size from 1 – 10 centimeters, and may have raised borders with fine adherent scales. This is what is often mistaken and mistreated for ringworm. Approximately 5 – 10 days after the herald patch appears, a generalized rash, or eruption, develops on the trunk and proximal extremities. These lesions are usually less than one centimeter in length, and are oval or round. They are slightly raised, and may be salmon colored-to-brown in appearance. Individual lesions may have a fine scaly center, giving it a “crinkly” appearance. The lesions on the back tend to align themselves along the cutaneous cleavage lines that lie obliquely, or diagonally, toward the spine. From afar, there is a so-called “Christmas tree” appearance to the lesions that is unique to P.R.
Pityriasis Rosea is a self-limiting and self-resolving skin condition that will clear up on its own without any treatment. The generalized eruptions last anywhere from 2 – 12 weeks, but are not contagious. Although unsightly, a person with P.R. does not need to be isolated or kept from others, and there is absolutely no reason for them to refrain from their normal activities.
John put on his T-shirt and gave his mom a gentle bear hug. “When we leave the doctor’s office, can you drop me off at the gym?” he quipped jokingly. She just looked up at the ceiling, rolled her eyes and shook her head.