The ringworm imitator — Pityriasis Rosea
The medical term for this condition is Pityriasis Rosea (PR). This condition is often mistaken for ringworm due to its initial appearance i.e a single oval or circular patch that appears 2-3 weeks before the general rash. This patch is scaly with flakes trailing just inside the edge. The initial patch is often mistaken as ringworm. An individual with this condition will usually apply an anti-fungal cream to the rash with no relief. Within a week or two, more patches, sometimes hundreds of them appear on the body — typically on the neck, arms and thighs but they are uncommon on the face. These patches are usually smaller than the first patch but have a similar appearance. These lesions follow the relaxed skin tension lines ("Langers" lines) on both sides of the back so that the rash has been described as looking like the outline of a Christmas tree. Not all patients experience itching but this is usually the reason why they seek help. The itch is especially intense when the patient becomes overheated (e.g exercising, working or playing in the sun). The intense itching is a sign of inflammation and results in dark patches on the skin that are unsightly and hard to treat. At this end stage, onlookers often mistake the rash for chicken pox.
The cause is unknown. The latest clinical research showed that a virus may cause this condition but this has not been proven. In my clinical experience, PR can occur more than once in an individual. Although in most textbooks or websites, it is written that it can occur only once. PR does not spread from person to person via contact. This condition, however, does occur in a cluster and is seasonal where several persons are usually affected the same time. Currently there is an outbreak as I have seen several cases in my office over the past two weeks. Any age can be affected but it is more common between the ages of 10-35 and there is no sexual preference. Occasionally there may be other flu-like symptoms, including tiredness and aching. The rash usually fades and disappears within 6-8 weeks but can sometimes last longer. Physical activity like jogging, running or even bathing in hot water may cause the rash to worsen or re-appear. In some cases, the patches may re-appear up to several months after the first episode and can continue for many months! This is often frustrating for both the doctors and the patients.
In the early phase, this condition is easily misdiagnosed by patients and even health providers (pharmacists, nurses, doctors). The typical pattern, i.e the Christmas tree appearance of PR during the course of this condition is often all that is required for a correct diagnosis. However, in the more difficult cases and/or when relapse is frequent, then a skin biopsy is usually performed to confirm the diagnosis.
• Cold showers should be encouraged to avoid worsening or a relapse of PR.
• Strenuous activity and heat should be avoided.
• Treatment is symptomatic, a topical steroid is normally given along with an oral antihistamine (Hiatal, Claritin,Cetrine, Allegra).
• In severe cases, anti-inflammatory medication such as oral corticosteroid may be given to stop the intense itching or to prevent spreading. In dark-skinned individuals, the aftermath of dark spots is harder to deal with than the condition itself.
• An exfoliating cleanser (ariSulfur facial cleansing bar or Aveeno bar) can be used to remove the dark spots left behind. If severe, a special compound fade cream can be prescribed by your dermatologist to speed up the process.
• Although it is unsightly and uncomfortable, PR is not a dangerous skin condition, even if it occurs during pregnancy.
• PR is a common skin disorder and is usually mild. Most cases usually do not require treatment and, fortunately, even the most severe cases eventually go away.
Dr Patricia Yap is a dermatologist at Apex Skin Care and Laser Center.