OBJECTIVE: Pityriasis rosea (PR) is a self-limiting acute rash with unclear etiology and pathogenesis. The cytokine pro le of PR is an infrequently
investigated  eld of research. The aim of this study was to assess the level of IL-36 in sera of patients with PR and its possible interrelation with
disease severity. METHODS: Forty patients with PR were included in this case-control study, and 40 comparable healthy control subjects. Severity
was assessed using pityriasis rosea severity score (PRSS) and serum IL-36 was assessed using ELISA. RESULTS: Serum IL-36 was signi cantly higher
in patients (30.36±12.35) pg/mL compared to control subjects (18.76±10.24) pg/mL (P=0.003). It correlates positively with severity as assessed
by PRSS (r= 627, P= 0.003). Patients who reported a history of COVID-19 had signi cantly higher levels of IL-36 (32.66±11.79) pg/mL compared
to those who have not (17.33±2.08) pg/mL (P= 0.000). CONCLUSION: Serum IL-36 could be considered a potential biomarker for pityriasis rosea
that correlates with the disease severity.