school refusal
n. An extreme fear of attending school.
Examples
2004
But now with child psychologists, "school refusal" has actually been coined as a medical term. The definition is what you would expect: the child is unreasonably scared of going to school. He or she might pretend to be sick or want to stay home because of a feeling of safety there.

Children express school refusal in different ways. Some will put up quite a fight getting out of bed and drag their feet in getting ready in the morning. Others find every little excuse to throw a tantrum in the
morning. Some children experience physical symptoms such as stomachache, headache or nausea.
—Manveet Kaur, “When your child won't go to school,” New Straits Times (Kuala Lampur, Malaysia), January 13, 2004
2003
It is important to distinguish between truancy — a child not wanting to go to school — and school refusal (or phobia) — whereby a child feels unable to attend. In such cases a pattern begins with vague complaints, often with physical symptoms such as nausea or abdominal pain, which can lead to panic attacks and, ultimately, outright refusal to attend.

While the condition can appear at any age, secondary schools, whose corridors are packed with older adolescents, can seem particularly intimidating to younger children. Your daughter is also at an age when she may be feeling increasingly self-conscious, which can make changing for PE or answering in class appear threatening. Perhaps she is being bullied.

Many cases of school refusal can be linked to family circumstances; for example, the recent death of a close relative or marital disharmony, which causes the child to feel anxious about separating from home.
—Julian Elliot, “Why does my daughter hate going to school?,” The Times of London, April 17, 2003
1983 (earliest)
With the holiday season nearing an end, schools and parents likely will see a new round of ''school phobia,'' a University of Virginia doctor says.

Dr. Anthony Richtsmeier Jr., who specializes in the treatment of psychosomatic illness in children, said school phobia can take the form of headaches, nausea and dizziness.

Known also as school refusal, school resistance, and separation anxiety, school phobia occurs most frequently following summers, weekends and school holidays, he said.
—“School jitters,” United Press International, January 02, 1983