The Pennsylvania Commonwealth Court reversed the Workers’ Compensation (WC) Appeal Board’s (Board) order that denied a Claim Petition for WC (Claim Petition). Claimant filed the Claim Petition, seeking WC benefits for Reactive Airways Dysfunction Syndrome. The WCJ granted the Claim Petition for medical bills only, declaring that Claimant met his burden of proving that his occupation as a fireman was a substantial cause of his pulmonary condition. Employer appealed. The Board reversed the WCJ’s decision, “ruling that the Presumption did not apply because Claimant failed to prove income loss, and Claimant’s medical evidence did not support a finding that Claimant’s pulmonary condition was work-related”. Claimant appealed to the Commonwealth Court, which reversed and held that “the Board erred by ruling that Claimant had to prove disability (i.e., earnings loss) before the WCJ could apply the Presumption”. The Court remanded “for application of the correct legal principles”.