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Pityriasis lichenoides is a clonal T-cell disorder that may develop in response to foreign antigens (eg, infections or drugs) and may be associated with cutaneous T-cell lymphoma.

Pityriasis lichenoides has acute and chronic forms existing in a clinical continuum. The acute form typically appears in children and young adults, with crops of asymptomatic chickenpox-like lesions that typically resolve within weeks to months. Antibiotics (eg, tetracyclineSome Trade Names
ACHROMYCIN V
TETRACYN
TETREX
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, erythromycinSome Trade Names
ERY-TAB
ERYTHROCIN
Click for Drug Monograph
) or phototherapy may help.

The chronic form initially manifests as flatter, reddish brown, scaling papules that may take months or longer to resolve. No treatment has proved effective.

Last full review/revision August 2009 by Peter C. Schalock, MD

Content last modified August 2009