Opinion ID: 2132937
Heading Depth: 1
Heading Rank: 2

Heading: The Aggravation and Eggshell Concepts.

Text: In Waits, as in the present case, the court instructed the jury on preexisting conditions under both the eggshell and aggravation concepts. We said: To clarify the scope of the instructions involved here, we start with the general rule that a defendant is liable only for injuries caused by the defendant's fault, and not for pain or disability resulting from other causes. Thus, if a plaintiff had a prior back injury that caused pain and a ten percent disability before the injury inflicted by the defendant occurred, the defendant would not be responsible for the disability and pain that predated the current injury, but only for any additional pain and disability caused by the current injury. Under these circumstances, an aggravation instruction is appropriately submitted to the jury. The eggshell plaintiff rule is an exception to the general rule. This exception applies only when the pain or disability arguably caused by another condition arises after the injury caused by the defendant's fault has lighted up or exacerbated the prior condition. The law on this point was clearly stated in Becker [ v. D & E Distributing Co., 247 N.W.2d 727 (Iowa 1976)]: It is also apparent mere existence of a prior nondisabling, asymptomatic, latent condition is not a defense. A tort-feasor whose act, superimposed upon such condition, results in an injury may be liable in damages for the full disability. In these cases the injury, and not the dormant condition, is deemed to be the proximate cause of the pain and disability. Waits, 572 N.W.2d at 577 (citations omitted) (quoting Becker, 247 N.W.2d at 731). Sleeth's orthopedic doctor testified that the accident would have aggravated her preexisting condition of osteoarthritis. The defendant has seized on this language as proof that the aggravation instruction was properly given. The plaintiff responds that aggravation, as used by the doctor, was not used in its legal sense but in the sense it had lighted up a dormant arthritic condition.