Lacking the 'protective label' of diabetes: Phenytoin-induced distal symmetrical peripheral neuropathy. A clinical case report

This report documents an unusual case of distal symmetrical peripheral neuropathy (DSPN) in an otherwise healthy patient without diabetes mellitus (DM) presenting to a podiatric wound care clinic. The development of gas gangrene coupled with Charcot neuroarthropathic changes ultimately resulted in a potentially life-saving transmetatarsal (TMT) amputation. Causation of, or at least a contributor to, the DSPN was likely phenytoin usage for epileptic seizures. Long-term use of phenytoin can lead to axonal shrinkage and random clusters of nerve demyelination [1]. Clinical standards for DM-induced DSPN indicate that annual comprehensive neurological assessment to detect nerve function deterioration is warranted [2]. This can aid in identifying patients at high risk of diabetic foot ulceration. However, oftentimes, patients exhibiting medication-induced neuropathy are not assessed to determine severity of the neuropathy nor are they educated about ulcer prevention in the same manner as patients with DM. This report advocates for a standardized threshold of diagnostic and preventative investigation for neuropathy of all aetiologies; diabetic, traumatic, viral, medication-induced and idiopathic.