A man with a rare case of diabetes complicating Charcot-Marie-Tooth disease (CMT) had a recurrent foot ulcer that was originally misdiagnosed as a diabetic foot.
This finding in a case report describes how overlapping symptoms can be difficult due to the two conditions, and how treating the ulcer with a simple discharge device resulted in sustained therapeutic benefit.
The report, “Diabetes co-occurring with Charcot-Marie-Tooth disease presenting as a recurrent foot ulcer mistakenly diagnosed as diabetic foot: a case report, ”Was published in the Journal of Diabetes Investigation.
Diabetes can cause loss of sensation due to nerve damage known as diabetic peripheral neuropathy (DPN). CMT is also a type of peripheral neuropathy and its symptoms can mimic those of diabetes, as in the case of loss of sensation in the extremities (hands and feet).
DPN can prevent diabetics from noticing minor infections and small wounds on their feet, which can turn them into serious infections and ulcers, a condition commonly known as “diabetic foot”. It is a serious complication that can lead to amputation and a higher risk of death.
Proper treatment depends on the exact diagnosis of the underlying cause of the condition, which can be complicated in disorders with significant symptomatic overlap.
Doctors at Sichuan University’s West China Hospital faced this challenge in the case of a 38-year-old man with concurrent CMT and diabetes who arrived at the hospital for treatment for a recurrent foot ulcer.
The man diagnosed with diabetes in 2013 chose not to have any diabetes treatment or blood glucose testing. Since 2016, he has had excessive urination, numbness in the lower limbs, and a decreased ability to feel pain and temperature changes.
Despite being prescribed metformin and methylcobalamin (a form of vitamin B12), his symptoms did not go away and he developed a recurrent ulcer on his right foot. This ulcer reappeared in 2019 when he was referred to West China Hospital.
At this point, the team saw an ulcer 1 cm in diameter on the patient’s right foot, as well as slight atrophy (waste) of the muscles of his thumb and lower limbs.
Although diabetes can damage the blood vessels in the back of the eye (the retina), the patient’s retina appeared normal. However, electromyography tests revealed nerve damage in all four limbs and particularly in the lower limbs with “severe motor and sensory injuries” [nerve] Fibers, ”wrote the team.
Imaging tests – x-rays and MRIs – also showed osteoporosis (weak bones) in both feet and excessive fat accumulation in the muscles, signs of CMT and diabetes, respectively.
The test results prompted doctors to conduct genetic tests that found duplication of the PMP22 gene, indicating CMT type 1A (CMT1A) and leading to the combined diagnoses of CMT1A and type 2 diabetes.
The patient was given a detachable, knee-high discharge device that is used to prevent ulcer relapse by allowing the patient to put less pressure on the affected foot. After this approach, the man’s ulcer did not return for a year of follow-up.
The team noted that diabetes rarely occurs with CMT1A. However, when it does, diabetes can make a CMT1A case worse, although it is known exactly how and why it is unknown.
While there is not yet a specific drug to treat CMT, the team suggested “unloading devices and desirable comprehensive management of [diabetes] can be beneficial to avoid pLantar [bottom of the foot] Ulcer recurrence and anti-progression of CMT. “
