What is Pityriasis Rosea?
Pityriasis rosea (PR), also known as pityriasis circinata, roseola annulata, and herpes tonsurans maculosus, is a temporary skin disorder that often starts with a slightly raised, oval, scaly patch known as the “herald patch.” This name refers to its rose-colored appearance. This skin condition is usually noticeable by a unique feature: after the first “herald patch” appears, more clusters of scaly oval patches typically develop on the torso and upper limbs, forming a pattern that resembles a “Christmas tree.” Usually, this skin condition lasts for 6 to 8 weeks.
Even though the “herald patch” is considered a hallmark sign of this disease, some reported cases might not present this characteristic. So it’s important to remember that not everyone who has Pityriasis rosea will necessarily have the initial “herald patch.”
What Causes Pityriasis Rosea?
The exact reason for ‘Pityriasis Rosea’ (PR), a skin rash, is not known. However, the fact that it changes with the seasons and affects people in the same place suggests that it may be caused by an infection. Causes of PR can include infections from viruses, bacteria, and spiral-shaped bacteria. It can also occur due to allergic reactions or problems with the body’s immune system.
It’s noticed that PR often comes after an infection of the upper respiratory tract, the area that includes your nose and throat. This suggests that Streptococcus, a type of bacteria, could play a role in causing this skin rash. Recent studies have also found that reactivations of human herpesvirus (HHV)-6 and HHV-7, which are usually inactive in the body, could be a possible cause for PR.
Some people have developed PR after getting vaccines, like BCG (a vaccine for tuberculosis), flu, H1N1, diphtheria, smallpox, Hepatitis B, pneumonoccus (a vaccine for pneumonia), and COVID-19. Others have seen PR rashes after taking certain medications, including gold compounds, captopril, barbiturates, D-penicillamine, clonidine, certain blood pressure and anti-inflammatory drugs, diuretics, certain antipsychotics, drugs for certain cancers, metronidazole, isotretinoin for acne, and clozapine.
Interestingly, people living in regions with mild climate tend to experience PR more often in the winter, while those living in tropical regions may see it happen in different seasons.
Risk Factors and Frequency for Pityriasis Rosea
Pityriasis rosea (PR), a skin condition, affects roughly 0.5% to 2% of the population. It impacts both men and women, but it’s seen more often in women. People between the ages of 15 and 30 are the most commonly affected. However, it also affects older adults and children. Interestingly, there are more cases spotted during the monsoon and fall seasons.
Signs and Symptoms of Pityriasis Rosea
Pityriasis Rosea (PR) is a skin condition marked by a “herald patch” or what’s also known as a mother patch, which is followed by scaly oval priques on the trunk and arms and legs nearer to the body. These form along the lines of skin cleavage, creating a pattern like a Christmas tree. This scaling is often observed and in 25% of cases, it can cause severe itching or pruritus. PR patches show up in 50% to 90% of patients, usually on the trunk, neck or arms and legs closer to the body. After 1 to 2 weeks of the herald patch appearing, a general skin eruption occurs with numerous lesions developing in groups. This often follows symptoms like a sore throat, upset stomach, fever, and joint pain. These lesions are typically symmetrical and occur commonly on the torso, back, abdomen, and areas adjoining the neck and arms and legs.
The secondary lesions are macules and papules, oval or elliptical in shape. They show fine scaling and central wrinkling, much like a cigarette paper. An outstanding feature of PR is the “collarette” appearance of the scale, with the edges attached at the periphery and lifted towards the middle of the lesion. The distribution of these lesions is usually widespread and bilateral, with the long axis running parallel to skin tension lines.
In 20% of cases, there might be atypical PR which is characterized by different morphology, size, and distribution of lesions as well as symptoms or the course of the condition. The different types of atypical morphologies include:
- Vesicular PR: This condition presents a generalized eruption of tiny fluid-filled sacs (or vesicles) mainly on the head, palms, and soles, needing distinction from varicella and dyshidrosis
- Purpuric (hemorrhagic) PR: This condition presents as brownish-purple discolorations on the skin or mouth lining
- Urticarial PR
- Generalized papular PR: It presents as multiple raised skin bumps along with classic patches and plaques, seen in young children, pregnant women, and African Caribbeans
- Lichenoid PR: It is seen during the course of atypical PR, but is more commonly caused by medications like gold compounds, captopril, barbiturates, D-penicillamine, and clonidine
- Erythema multiforme-like PR: It presents with target-like lesions along with classical lesions of PR. Under microscope, erythema multiform and PR may look alike, except for satellite cell necrosis which is only seen in erythema multiform
- Follicular PR: The secondary lesions of this condition are typically follicular and occur discretely or in groups associated with classical lesions
- Giant PR: This condition has plaques and circles of very large sizes, with some reaching the size of the patient’s palm; it is rarely reported
- PR presenting as exfoliative dermatitis
- PR with atypical herald patch: The herald patch may be absent in 20% of patients; alternately, this condition may present with secondary eruptions or occur at unusual sites such as the face, scalp, genitalia, or other sites
- Inverse PR: In this condition, lesions are mainly present in the armpit, groin, and face
- Acral PR: Here, lesions are more concentrated over acral parts of the body, where diseases like erythema multiforme, syphilis, necrolytic acral erythema, and drug eruptions should be considered
- Unilateral PR: This rare variant of PR can happen in both kids and adults; lesions happen on one side of the body, and patients show a herald patch with classical secondary lesions
- Blaschkoid PR: In this condition, the PR lesions follow the lines of Blaschko
- Limb-girdle PR, also known as PR of Vidal has eruptions limited to the shoulders or pelvic girdle
- Mucosal involvement in PR: This variant is seen in 16% of patients with PR; it affects the mouth lining, with multiple symptoms including small, raised reddish spots, erosive, fluid-filled sacs, bleeding, ulcers, raised borders on ulcers, petechiae, pustule-like vesicles, larger fluid-filled sacs, and reddish patches
- Localized PR: Here, eruptions are localized to one part of the body
PR rashes usually last for 5 weeks and resolve by 8 weeks in over 80% of patients. PR needs to be differentiated from secondary syphilis, ringworm, guttate psoriasis, nummular eczema, chronic pityriasis lichenoid, cutaneous T-cell lymphoma, and certain types of erythema.
Testing for Pityriasis Rosea
Dermatoscopy, a skin examination method, can help distinguish Pityriasis Rosea (PR) from other skin conditions. When using this technique, the skin typically appears yellowish in color, the scales are arranged around the edge, and the small blood vessels appear to be distributed in a scattered manner.
If a tissue sample or biopsy is taken for a more detailed microscopic analysis – a process called histopathology – a few characteristic features are identified. This includes skin inflammation around small blood vessels, uneven skin cell growth, and buildup of cells in certain areas. Additionally, the outermost layer of the skin may show migration of certain white blood cells, mild thickening, and a thin layer of skin cells that help with waterproofing and protection. In the deeper skin layers, there are leaked red blood cells and clumps of different types of white blood cells including lymphocytes, histiocytes, and eosinophils.
Treatment Options for Pityriasis Rosea
Pityriasis Rosea (PR) is a condition that causes a temporary skin rash. It generally resolves on its own over time, but some treatments may help speed up the healing process and manage symptoms. These treatments include specific steps like using moisturizers to soothe and hydrate the skin, replacing traditional soaps with gentler alternatives, and being careful about sun exposure which can help the skin’s recovery without causing sunburn.
Most people find relief from symptoms using basic remedies such as skin-smoothing lotions (emollients), medicines to stop itching (antihistamines), and creams to reduce inflammation and help the skin heal (topical steroids). Some types of medications such as macrolides and acyclovir can also help speed up the fading of the rash and provide relief from itchiness.
Another treatment option involves the use of a specific kind of light therapy, known as Narrowband Ultraviolet B therapy. This treatment helps modify the immune response in the skin and has shown promising results in patients by aiding in the healing process.
What else can Pityriasis Rosea be?
The skin condition known as PR can look like several other diseases. Therefore, other health concerns need to be ruled out before diagnosing someone with PR. These conditions to be excluded include:
- Erythema multiforme – a type of skin rash
- Guttate psoriasis – a skin condition causing small, red spots
- Kaposi sarcoma – a kind of skin cancer
- Lichen planus – a rash that can cause bumps or lesions
- Parapsoriasis – a group of skin disorders
- Pediatric syphilis – a sexually transmitted infection in children
- Pityriasis alba – a skin disorder causing pale patches
- Seborrheic dermatitis – a skin disease that causes flaky, itchy skin
- Tinea corporis – a fungal infection of the skin, also known as ringworm
- Tinea versicolor – a fungal infection that leads to discolored patches of skin
What to expect with Pityriasis Rosea
Pityriasis rosea is a skin condition that usually gets better on its own within a few weeks to months. For most people, this illness doesn’t significantly affect their overall health. The main symptom is often a mild-to-moderate itchiness that comes with the rash.
It’s rare for this condition to reoccur in an individual’s lifetime, with less than 5% of people experiencing a second round. Complications like bacterial skin infections due to scratching are also uncommon.
Though it’s been suggested that some systemic associations exist, these instances are infrequent. A healthcare professional can provide accurate diagnosis, guidance, and reassurance because of the typically favorable outcome of pityriasis rosea.
Possible Complications When Diagnosed with Pityriasis Rosea
Pityriasis Rosea (PR) usually gets better on its own after a few weeks or months and doesn’t typically lead to severe problems. However, in rare instances, some people might face complications:
- Secondary bacterial infection: This can happen if someone scratches the infected area of skin. The added bacteria can lead to symptoms like pain, redness, and pus.
- Itching and discomfort: PR can lead to intense itching, particularly during the early stages of the condition. This can result in disturbed sleep and can affect a person’s quality of life.
- Hyperpigmentation: In some cases, the rash might go away but leave dark patches on the skin that can take several months to disappear.
- Recurrence: While not common, some people might experience the rash return, typically within a few months of the first incident.
- Other rare complications: Other rare complications linked to PR are instances of early birth and fetal death during pregnancy (within the first trimester up to 15 weeks of pregnancy). There are also a few reported cases where exposure to the viruses HHV-6 and HHV-7 led to an allergic reaction to medication.
Preventing Pityriasis Rosea
One way to avoid getting PR, or also known as Pityriasis Rosea, is by not getting too close to people who already have it and by maintaining good habits when it comes to cleanliness. This can help decrease the chance of spreading PR and potentially prevent it from spreading to other people.
Getting educated about PR is vital in managing this skin condition. It’s important to understand what causes it, how long it’s expected to last, and the importance of finding relief from the symptoms it can cause. Even though the rash from PR typically goes away on its own without treatment, topical corticosteroids, antihistamines, and moisturizers can help soothe the rash and help it heal.
Avoiding harsh soaps, hot water, and too much sun can help the rash heal. It’s also a good idea to wear loose-fitting clothes and avoid activities that make you sweat excessively as these can cause the rash to worsen.
People with PR should get immediate medical help if they have severe symptoms like intense itching, pain, or fever. In such scenarios, doctors might need to do extra testing to make sure that no other conditions are causing these symptoms.