Names of illnesses
The phrases「~にかかりました」 ([name of illness] ni kakarimashita) and「~にかかってしまいました」 ([name of illness] ni kakatte shimaimashita) both mean "I got/contracted (an illness)", and they can be used to mean that you contracted an illness and got over it, or that you contracted an illness and are still sick.
Some names of illnesses that you may encounter are 「中耳炎」 (chuji-en, or "inner ear infection"),「水ぼうそう」(mizuboso, or "chickenpox"),「突発性発疹」(toppatsu-sei hosshin, or "roseola"),「溶連菌(感染症)」(yorenkin [kansen-sho], or "streptococcal infection"),「おたふく(かぜ)」(otafuku [kaze], or "mumps") and「インフルエンザ」(infuruenza, or "influenza"). Some of these illnesses are also commonly encountered in the names of vaccines and so on. There are of course many other illnesses that your child may contract, so if a doctor gives your child a diagnosis of an illness that you are not familiar with, ask the doctor to write down or tell you the name of the illness, and be sure to convey this information to your child's preschool.