The “Eggshell Plaintiff Rule”: What is it and how can it affect your case?

  • Apr 01, 2022

Legal Update by Attorney Marshall Tuttle and Law Clerk Jordan Gehlhaar

Iowa Uniform Jury Instruction 200.34 is titled “Previous Infirm Condition” and reads: 

If plaintiff had [a] condition making [them] more susceptible to injury than a person in normal health, then the defendant is responsible for all injuries and damages which are experienced by plaintiff that are caused by defendant's actions, even though the injuries claimed produce a greater injury than those which might have been experienced by a normal person under the same circumstances.

This is known as the “Eggshell Plaintiff Rule.” It originates from the idea that some victims have an “eggshell-thin” skull which results in abnormally excessive damage. The rule requires the person causing the injury to be liable for all damage, even though most people would not experience the same effects or require the same treatment. It applies in personal injury cases where the victim is more susceptible to injury because of their pre-existing condition. For example, if you’re involved in a minor car accident and the other driver has osteoporosis or heart disease, you are still liable for their substantial medical care even if a “healthier” person would not have required care. Therefore, this rule can make damages—such past and future medical expenses—much higher.

The Iowa Supreme Court recently discussed this instruction in Mengwasser v. Comito and Capital Fruit Company. The plaintiff in that case was rear-ended by a vehicle traveling approximately five miles per hour; the airbags did not deploy. She requested an eggshell plaintiff instruction under the theory that degenerative disk disease in her neck made her more susceptible to injury. The trial court denied this instruction and she appealed. The appellate court affirmed, finding the plaintiff had only proven she aggravated a previous injury, which is not the same as proof of a greater susceptibility to injury.

For this instruction to apply, the plaintiff must request it prior to trial. Additionally, there must be evidence showing that prior to the injury, a condition made them more vulnerable or prone to injury than a person of average health. This can be determined through medical records, discovery responses, and correspondence with opposing counsel.

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