In Bethlehem Steel Corporation v. Workmen's Compensation Appeal Board (Baxter), 550 Pa. 658, 708 A.2d 801 (1998), the claimant suffered from pre-existing, non-work-related asthma, and, while employed as a welder by the employer, sustained a work-related injury caused by an aggravation of that condition after being exposed to paint fumes at work. The employer paid the claimant benefits for the related period of disability. After a period of time, the claimant's lung functions returned to normal, but, on his physician's recommendation, the claimant did not return to the work because that would again aggravate his pre-existing condition. The claimant applied for workers' compensation benefits, which the workers' compensation judge (WCJ) granted. The Workers' Compensation Appeal Board (WCAB) and this court both affirmed, concluding that when a return to work would exacerbate a pre-existing condition, the employee is entitled to benefits even if the pre-existing condition is not work related. The supreme court disagreed, concluding it undermines the principles of the Act to impose liability on an employer for a pre-existing condition when no residual work-related injury is demonstrated. Because the claimant had completely recovered from the work-related injury, i.e., aggravation of asthma, and his loss of earning power was due solely to non-work-related causes, the supreme court held that the claimant was ineligible for benefits.