A junior Dr. Fishbein? An invitation for kids to outguess their doctors or come down with imaginary meningitis. . . mononucleosis. . . food poisoning. . . what have you? Relax. Dr. Donahue, a pediatrician, simply recognizes children's curiosity about germs and sickness and believes they have a right to be set straight. Reassuringly (his most often repeated statement is that a certain ailment used to be more serious or severe or common before the age of antibiotics) but not falsely so, and with only occasional recourse to cuteness (""the good thing about a urine test is that you can pass it without studying""), he explains here the common infectious diseases, along with ""some you probably won't get,"" just as if he were briefing one of his young patients. Along the way he eases in relevant anatomy, word definitions, likely remedies and the ""detective work"" that goes into diagnosis; common misconceptions are corrected gently with reminders that antibiotics can't kill a virus, you can't get pneumonia (""whether you button your coat or not"") if you don't have the germs that cause it, the rust on a nail has nothing to do with tetanus, and--despite Mama's anxieties--you won't starve if you rest an upset stomach. You can see why one of Donahue's ten-year-old patients suggested that he write a book.