Merck Manual

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Pityriasis Lichenoides

By

Shinjita Das

, MD, Harvard Medical School

Reviewed/Revised Sep 2023
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Topic Resources

Pityriasis lichenoides is a clonal T-cell disorder that may develop in response to foreign antigens (eg, infections or substances) and may be associated with cutaneous T-cell lymphoma. Diagnosis is clinical. Treatment may include various topical and oral medications.

Pityriasis lichenoides has distinct acute and chronic forms, which are usually distinct entities; however, lesions may evolve from the acute to the chronic form. The acute form typically appears in children and young adults, with crops of asymptomatic chickenpox-like lesions that typically resolve, often with scarring, within weeks to months. Lesions that appear erythematous on light skin may appear more violaceous (purple) or brown on dark skin.

Antibiotics (eg, tetracycline, erythromycin) or phototherapy may help.

The chronic form of pityriasis lichenoides initially manifests as flatter, reddish brown, scaling papules that may take months or longer to resolve.

Diagnosis of Pityriasis Lichenoides

Treatment of Pityriasis Lichenoides

  • Various topical and oral treatments

Treatment of pityriasis lichenoides is often ineffective, but sunlight, topical corticosteroids, topical tacrolimus, oral antibiotics, phototherapy, and immunosuppressants have been used with varying success (1 Treatment reference Pityriasis lichenoides is a clonal T-cell disorder that may develop in response to foreign antigens (eg, infections or substances) and may be associated with cutaneous T-cell lymphoma. Diagnosis... read more Treatment reference ).

Treatment reference

  • 1. Bowers S, Warshaw EM: Pityriasis lichenoides and its subtypes. J Am Acad Dermatol 55:557–572, 2006. doi: 10.1016/j.jaad.2005.07.058

Drugs Mentioned In This Article

Drug Name Select Trade
Emtet-500, Panmycin, Sumycin
A/T/S, Akne-mycin, E.E.S., Emcin Clear , EMGEL, E-Mycin, ERYC, Erycette, Eryderm , Erygel, Erymax, EryPed, Ery-Tab, Erythra Derm , Erythrocin, Erythrocin Lactobionate, Erythrocin Stearate, Ilosone, Ilotycin, My-E, PCE, PCE Dispertab , Romycin, Staticin, T-Stat
ASTAGRAF XL, ENVARSUS, HECORIA, Prograf, Protopic
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NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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