My student eats erasers and crayons, is this an indicator of something serious?

I have a 5 year old student who is eating crayons and erasers on a regular basis. After talking to his mother, she told me that he also ate a hole in his brand new bunk bed made of wood and paper. He is constantly eating things like this and I am concerned that it may mean something more serious.
Concerned Teacher

[Renee Radenberg]

There is an eating disorder called 'Pica' which children and adults eat non-food objects. Pica occurs more frequently with children. The causes of Pica are unknown, however, certain situations may increase the risk to it such as nutritional deficiencies of iron or zinc (the nonfood items craved usually do not supple the minerals lacking in the body), malnutrition (seen in underdeveloped countries where people will eat clay or soil), development problems (mental disabilities, and autism) and mental health conditions (obsessive-compulsive disorder and schizophrenia). Children at that age do put all types of items in their mouth; however, they do not usually eat them. Consumption of some non-food object maybe harmless, however, Pica is considered a serious eating disorder that may result in serious health issues such as lead poisoning and iron deficiency anemia. I am not saying he has Pica, but strongly suggest he be seen by his MD and get checked.