Pityriasis Lichenoides Chronica in a Patient With Ankylosing Spondylitis Treated With Etanercept.

Background: Pityriasis lichenoides chronica, a papulosquamous disorder often considered a subtype of pityriasis lichenoides. It is considered a clonal T-cell disorder, which may be associated with cutaneous T-cell lymphoma that may develops in response to foreign antigens.
Case Presentation: We present a 38-year-old male patient with ankylosing spondylitis who was on treatment with etanercept. After 8 weeks of treatment, the patient presented with scaly erythematous papules, on the back and arms. He was diagnosed clinically with pityriasis lichenoides chronica.
Conclusion: Pityriasis lichenoides chronica should be included among the broad clinical spectrum of chronic inflammatory skin diseases which may occur during treatment with TNF-alpha antagonists. J Drugs Dermatol. 2020;19(5): doi:10.36849/JDD.2020.2191.