succinic acid ,butanedioic,has a role in the citric acid cycle(energy cycle) and can be increased due to products with chemicals eg shampoo, hair relaxer,hair color and bleaching.The oxidation reaction gives reduction of ubiquinone (Coenzym Q10) .
In children genetic disorders in energy metabolism
can be the origin of the increase in succinic acid.This might be a mitochondrial( energy organelles in the cell) disturbance.Also atypical PKU
(difficulty in excreting phenols) might be present.
You will need to have lab tests done by an pediatrician