Maximal Usage Pharmacokinetics and Safety Study of ARQ-154 Foam 0.3% in Pediatric Participants With Scalp and Body Psoriasis

ARQ-154-127 is a Phase 1, open-label, single arm, maximum usage pharmacokinetic and safety study of roflumilast foam 0.3% in participants with scalp and body psoriasis. The goal of the study is to: * Evaluate the systemic exposure and characterize the plasma pharmacokinetic (PK) profile of ARQ-154 foam 0.3%. * Assess the safety and tolerability of ARQ-154 foam 0.3%