Pityriasis Lichenoides

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PatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.

Synonym: Mucha-Habermann disease

Pityriasis lichenoides is a rare skin disorder of unknown aetiology, characterised by multiple papules and plaques. It is a self-limiting papulosquamous disease that may persist for years and is associated with a high relapse rate. There are three types:

  • An acute, short-lived form usually found in children - pityriasis lichenoides et varioliformis acuta (PLEVA)
  • A more chronic form known as pityriasis lichenoides chronica (PLC)
  • Febrile ulceronecrotic PLEVA (very rare)
  • Pityriasis lichenoides most often affects adolescents and young adults aged under 30 years. It is slightly more common in males. It is rare in infants and in old age.
  • The cause of pityriasis lichenoides is not yet known but three major theories exist:
    • An inflammatory reaction triggered by infectious agents.
    • A relatively benign form of T-cell lymphoproliferative disorder (lesions of patients with pityriasis lichenoides show the presence of immune T-cells with specific CD30+ markers or antigens in PLEVA, and loss of CD7 antigens on T-cells in PLC).
    • An immune complex-mediated hypersensitivity vasculitis (some patients have circulating immune complexes (aggregations of antigens and antibodies) deposited in their skin).
  • Infections that have been associated with both PLC and PLEVA include Toxoplasma gondii, Epstein-Barr virus, HIV, cytomegalovirus, parvovirus, Staphylococcus aureus and group A beta-haemolytic streptococcus.

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  • PLEVA lesions may evolve into lesions of PLC. Lesions that are clinically consistent with both PLEVA and PLC are often found on physical examination.
  • Most lesions heal with post-inflammatory changes - eg, transient or persistent hyperpigmentation.
  • Rarely, dark-skinned people may present with widespread macular hypopigmentation. This variant is most common in children.
  • Lesions may be symmetrical or asymmetrical, and particularly occur on the trunk, buttocks, and proximal extremities. Lesions may also appear on the palms, soles, face and scalp.

Pityriasis lichenoides et varioliformis acuta (PLEVA)

  • The common variant of PLEVA presents with the sudden appearance of multiple red papules on the trunk, buttocks, and proximal extremities. It can, however, occur anywhere on the body.
  • Papules rapidly progress to vesicles and haemorrhagic crusts. They are often covered with a fine scale.
  • Minor systemic upset may occur.
  • Lesions of PLEVA are often associated with burning and pruritus.
  • The spots come up in crops. The rash may resemble chickenpox but takes much longer to clear.
  • Febrile ulceronecrotic PLEVA (Mucha-Habermann disease) presents with a sudden eruption of diffuse coalescent necrotic ulcerations associated with high fever, malaise and myalgia. These lesions are usually very painful.

Pityriasis lichenoides chronica (PLC)

  • PLC has a more low-grade clinical course than PLEVA.
  • PLC usually presents with a small pink papule that turns a reddish-brown colour.
  • A fine scale is usually seen. The eruption is often polymorphic, with lesions at different stages of development.
  • PLC is usually distributed over the trunk, buttocks, and proximal extremities. It may also occur on the hands, feet, face and scalp.
  • The spots look less angry and are covered with a firm shiny scale. The scale, covering the top of a spot, can be scraped off as a single chunk, to reveal a shiny brownish surface underneath.
  • Although the spots fade over several months or even years in some cases, new spots may appear.
  • PLC lesions may appear over the course of several days, weeks or months. Lesions at various stages may be present at any one time.
  • Unlike PLEVA, lesions are not painful, itchy or irritable.
  • Diagnosis is based on clinical appearance and usually confirmed by skin biopsy (shows a lymphocytic vasculitis).
  • Other investigations are directed towards possible associated diseases and the differential diagnosis; they may include antistreptolysin O titres, ESR, HIV screening, infectious mononucleosis tests, cytomegalovirus serology, Epstein-Barr virus serology and toxoplasma serology.

Often no treatment is required and the condition resolves spontaneously. In cases where treatment is necessary, recommended first-line therapies include:

  • Topical steroids to reduce irritation.
  • Topical immunomodulators - eg, tacrolimus or pimecrolimus.
  • Oral antibiotics; the most common antibiotics used are erythromycin and tetracycline.
  • Phototherapy is beneficial in the treatment of subacute or chronic disease (sun exposure in summer helps). Both psoralen combined with ultraviolet A (PUVA) and ultraviolet B (UVB) may result in clearing but relapses are not uncommon.
  • Monotherapy using narrow-band UVB (NB-UVB) can be effective in achieving a complete response in the treatment of pityriasis lichenoides.[1] 
  • For resistant cases systemic steroids, methotrexate, acitretin, dapsone or ciclosporin may be used.
  • Aggressive treatment with immunosuppressant and/or immunomodulating agents as well as intensive supportive care are recommended for febrile ulceronecrotic PLEVA.
  • TNF-alpha inhibitors (eg, infliximab) may be useful for patients with febrile ulceronecrotic PLEVA, particularly in resistant cases.[2] 
  • Although pityriasis lichenoides presents similarly in adults and children, it runs a longer course in children.[3] 
  • Usually, prognosis is good, with spontaneous resolution. Resolution may just take several months; however, it may take much longer.
  • Many patients have relapses of this condition.
  • Ulceronecrotic PLEVA can lead to scarring.
  • Ulceronecrotic PLEVA carries a great morbidity and is potentially fatal.[4] 

Further reading & references

  1. Park JM, Jwa SW, Song M, et al; Is narrowband ultraviolet B monotherapy effective in the treatment of pityriasis lichenoides? Int J Dermatol. 2013 Aug;52(8):1013-8. doi: 10.1111/j.1365-4632.2012.05814.x. Epub 2013 Jun 20.
  2. Meziane L, Caudron A, Dhaille F, et al; Febrile ulceronecrotic Mucha-Habermann disease: treatment with infliximab and intravenous immunoglobulins and review of the literature. Dermatology. 2012;225(4):344-8. doi: 10.1159/000346245. Epub 2013 Jan 31.
  3. Koh WL, Koh MJ, Tay YK; Pityriasis lichenoides in an Asian population. Int J Dermatol. 2013 Mar 14. doi: 10.1111/j.1365-4632.2012.05608.x.
  4. Nanda A, Alshalfan F, Al-Otaibi M, et al; Febrile ulceronecrotic Mucha-Habermann disease (pityriasis lichenoides et varioliformis acuta fulminans) associated with parvovirus infection. Am J Dermatopathol. 2013 Jun;35(4):503-6. doi: 10.1097/DAD.0b013e3182770626.

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.

Original Author:
Dr Colin Tidy
Current Version:
Peer Reviewer:
Dr John Cox
Document ID:
2616 (v22)
Last Checked:
Next Review:

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