Pityriasis Rosea

What is Pityriasis Rosea?
Pityriasis rosea is a rash that usually begins as a large, circular or oval, slightly large, scaly spot on the chest, abdomen or back and less often on the face, scalp or near the genitals. Often called a herald patch, this spot can be up to 10 cm across. It is typically followed (after around 2 weeks) by smaller spots from the middle of your body which resemble a pine-tree pattern. These rashes might continue to spread over the following 2–6 weeks although they can last for up to 5 months. 

Before the herald patch appears, some people experience headache, fatigue, fever, decreased appetite or sore throat. Pityriasis rosea can cause itching, which is occasionally severe especially on exercising, exposure to heat or in stressful conditions.

In light-skinned people, the patches are usually pinkish red & in dark-skinned people, these might be grey, dark brown, or black. It usually goes away on its own within 10 weeks. It’s not contagious and in most people, it does not leave marks or scars after it heals.

However, you should meet your doctor if you develop a persistent rash.

Who gets it?
It can affect any age group, but commonly occurs between the ages of 10 and 35. Pityriasis rosea is, for the most part, equally common in men and women. It has no racial predominance. Most people only develop pityriasis rosea once in their lifetime.

What triggers it?
Although the exact causes are still unknown, it is thought to be related to a viral infection, in particular by certain non-common strains of the herpes virus. Certain drugs can trigger pityriasis rosea. These include angiotensin-converting enzyme inhibitors, nonsteroidal anti-inflammatory drugs, hydrochlorothiazide, imatinib, clozapine, metronidazole, terbinafine, gold and atypical antipsychotics. 

Complications
Complications due to pityriasis rosea are rare. Few complications include severe itching and/or lasting brown spots on dark skin, after the rash has healed.

If pityriasis rosea occurs early in pregnancy, within the first 15 weeks, there seems to be a greater chance of miscarriage. In addition, children of affected mothers may be prone to premature delivery. Affected mothers are closely monitored for potential problems. Occasionally, treatment with acyclovir is considered.Also, if the condition does not improve within 3 months, you need to revisit your doctor.

How is it diagnosed?
Physical examination, blood test, scraping for microscopy, or biopsy

How is it treated?
Pityriasis rosea usually is self-limited and requires no treatment and resolves spontaneously. Treatment is not necessary if the rash does not cause significant symptoms. Typically, pityriasis rosea will usually clear on its own within 6–9 weeks without medical intervention.

To help with the itching, your doctor may recommend:

• Over-the-counter topical medications, such as calamine lotion or zinc oxide

• Antihistamines, often taken for allergies (to treat rashes and itching)

• Lukewarm showers or soaking in oatmeal baths

In some cases, your doctor may want you to take prescription drugs such as corticosteroids, which lessen itching and swelling, or acyclovir which is an antiviral that counters herpes.

Natural or artificial sunlight might also be prescribed. Light therapy may cause lasting darkening in certain spots, even after the rash clears. Reduced exercising and avoidance of hot showers and baths might also be recommended.

You should consult Dr Divya Sharma  before using any medication.