Pityriasis Rosea

WHAT IS PITYRIASIS ROSEA?

Pityriasis rosea is a common, self – limiting skin disorder that mostly affects the chest, the back and the proximal extermities. Its etiology, although associated with herpesviruses HHV-6 and HHV-7, still remains partially unknown.

EPIDEMIOLOGY

The condition is more common in women than in men and usually appears in young adults being 15 – 35 years old, with a peak age of ±23 years old. The lesions often show shortly after an episode of symptoms characteristic for a viral upper respiratory tract infection (dry cough, cold, sore throat, runny nose). No specific predisposing factors have been noted.

...a singular so - called “herald patch” or “plaque mère” appears, often on one’s torso. It is the biggest lesion in the course of the disease, of an oval shape, pinkish color on the outside and skin color in its center, with peripheral scaling and peeling. It heralds a more extensive, secondary rash on the chest, the back and the proximal extermities which usually shows 1-20 days afterwards and often follow the pattern of a "christmas tree".

WHAT CAUSES PITYRIASIS ROSEA?

The etiology of pityriasis rosea is not completely known. It is linked to a reactivation of herpesviruses 6 and 7, the same pathogens which are responsible for roseola or the sixth disease in infants. Similar rashes have been observed as an adverse reaction to certain medicine e.g. angiotensin – converting enzyme inhibitors, nonsteroidal anti – inflammatory drugs, hydrochlorothiazide, atypical antipsychotics, isotretinoin, or metronidazole.

SIGNS AND SYMPTOMS

The disorder has a typical clinical course with characteristic stages. Firstly, after an upper respiratory tract infection, a singular so – called “herald patch” or “plaque mère” appears, often on one’s torso. It is the biggest lesion in the course of the disease, of an oval shape, pinkish color on the outside and skin color in its center, with peripheral scaling and peeling. It heralds a more extensive, secondary rash on the chest, the back and the proximal extermities which usually shows 1-20 days afterwards and often follow the pattern of a “christmas tree”. The subsequent lesions are abundant yet smaller, in the form of scaly, well – demarcated, pinkish patches or plaques. Similarly to the plaque mère, the scaling or peeling tends to take place at the periphery of the lesion. The rash can itch or not at all. It is self – limiting and lasts for about 4-6 weeks, however around 2% of the patients are prone to relapses that go on from months to years. Systemic symptoms like fever or chills are not present.

"Look out for changes in the appearances of moles on your skin and call your dermatologist's attention to any changes (growth, bleeding, asymmetry, itching, pain)"

GENERAL DAILY MEASURES

PHOTOTHERAPY

Phototherapy is one of the commonly chosen options in pityriasis rosea, especially if the lesions seem to be persistent, extensive or especially burdensome to the patient. The beneficial effect of UVB in this particular condition has been well-documented. Pennsylvania Dermatology Specialists will assess if phototherapy would be advantageous to you and if so, will individually optimize its parameters.

PHARMACOLOGICAL THERAPY

Since pityriasis rosea is a self – limiting condition, in most cases no pharmacological treatment is necessary. Nevertheless, if the symptoms happen to be particularly cumbersome, a doctor might prescribe some medication. Amongst topical therapies steroids from group V (hydrocortisone, fluticasone propionate) as well as menthol solutions are applied. When it comes to possible oral treatments, a 2 – week erythromycin (Erythrocin®) course seems to be helpful because of the drug’s anti – inflammatory benefits. In cases of intense itching, oral antihistamines (fexofenadine, loratadine) can be prescribed. Sometimes, oral antiviral medications such as valacyclovir are used as well to target the causative virus. Sometimes, when the rash is unusually extensive, a short course of prednisone is used. Pennsylvania Dermatology Specialists will choose the best pharmacological treatment in your individual case.