Rare Pediatrics News

Disease Profile

Pityriasis lichenoides

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

Unknown

Age of onset

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ICD-10

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Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Categories

Skin Diseases

Summary

Pityriasis lichenoides (PL) is a skin condition characterized by small, raised pink spots that tend to come together in groups. It is not contagious. There are two main types of PL: an acute form called pityriasis lichenoides et varioliformis acuta (PLEVA), and a milder, longer-lasting form called pityriasis lichenoides chronica (PLC).[1] There is also a rare, severe variant of PLEVA called febrile ulceronecrotic PLEVA, associated with high fever and complications that may affect other body systems.[2]

In both types of PL, spots usually occur on the trunk, buttox, arms and legs.[1][2] PLEVA begins abruptly and may cause itching or burning.[1][2] PLC may develop over days, is less irritating, and lasts longer than PLEVA.[2] Spots associated with PLC typically fade within 3 to 4 weeks, but new spots may then appear.[1] There is no clear consensus regarding how long either form of PL lasts, but most cases resolve on their own within one to several months. Some cases may wax and wane, or relapse over a period of years.[2]

The cause of PL is not known. Theories on the cause have included the possibility of a low-grade or self-limited lymphoproliferative disorder; a reaction to a bacterial or viral infection; and an inappropriate, inflammatory immune response to an unknown foreign agent.[2]

Treatment options may include antibiotics, phototherapy, PUVA, or medications that suppress the immune system response (immunosuppressants) in severe cases.[1][2]

Cause

The exact cause of pityriasis lichenoides (PL) remains unknown. Theories on the cause have included the possibility of a low-grade or self-limited lymphoproliferative disorder; a hypersensitive reaction to a bacterial or viral infection; and an inappropriate, inflammatory immune response to an unknown foreign agent. The most commonly reported associated infections in people with PL are Epstein-Barr virus (EBV), Toxoplasma gondii, and human immunodeficiency virus (HIV).[2] Other infections that have been associated with PL include cytomegalovirus, parvovirus (fifth disease), Staphylococcus aureus, and group A beta-haemolytic streptococci.[3] Several therapies, such as chemotherapeutic agents, estrogenprogesterone therapy, the antihistamine astemizole, certain herbs (e.g. kampo), and the measles vaccine have also been linked to the onset of PL.[4] However, no cause-effect relationship between PL and any of these infections or therapies has been proven.[4][2] PL is not contagious.[1]

Treatment

Most cases of pityriasis lichenoides (PL) tend to resolve on their own over time.[2] However, treatment may be used to decrease the duration of the condition, especially if the rash is a nuisance.[1] Initial treatment for PL usually consists of topical or systemic corticosteroids, or oral antibiotics. However, these treatments may cause multiple side effects and are not always effective.[5] Natural sunlight and/or phototherapy treatment may be helpful. A combination of tablets known as Psoralens with UVA (PUVA treatment) may also be helpful, but carries a higher risk of side effects. Severe forms of the disease may be managed by medications that suppress the immune response (immunosuppressants).[1]

Information about specific medications that may be used to treat PL is available on Medscape Reference's website here.

Organizations

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Social Networking Websites

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

      • The American Osteopathic College of Dermatology provides information on Pityriasis lichenoides.
      • The British Association of Dermatologists provides an informational leaflet on pityriasis lichenoides. Click on the British Association of Dermatologists link to view this leaflet.
      • DermNet NZ is an online resource about skin diseases developed by the New Zealand Dermatological Society Incorporated. DermNet NZ provides information about this condition.

        In-Depth Information

        • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Pityriasis lichenoides. Click on the link to view a sample search on this topic.

          References

          1. PITYRIASIS LICHENOIDES. British Association of Dermatologists. September, 2016; https://www.bad.org.uk/shared/get-file.ashx?id=115&itemtype=document.
          2. Mark Tye Haeberle. Pityriasis Lichenoides. Medscape Reference. February 25, 2016; https://emedicine.medscape.com/article/1099078-overview.
          3. Pityriasis Lichenoides. DermNet NZ. 1998; https://www.dermnetnz.org/topics/pityriasis-lichenoides/.
          4. Khachemoune A and Blyumin ML. Pityriasis lichenoides: pathophysiology, classification, and treatment. Am J Clin Dermatol. 2007; 8(1):29-36. https://www.ncbi.nlm.nih.gov/pubmed/17298104.
          5. Maranda EL, Smith M, Nguyen AH, Patel VN, Schachner LA, and Joaquin JJ. Phototherapy for Pityriasis Lichenoides in the Pediatric Population: A Review of the Published Literature. Am J Clin Dermatol. December 2016; 17(6):583-591. https://www.ncbi.nlm.nih.gov/pubmed/27502793.

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