Have you tried any topical formulations? A compounded gel of amitriptyline 1% with ketamine 0.5% seems to be the Mayo Clinic’s preferred prescription for erythromelalgia. Another topical treatment would be a lidocaine patch. A more drastic option would be a systemic lidocaine infusion. Pregabalin (Lyrica) has also been found to be beneficial for some EM patients.
A teenage girl in Australia whose symptoms were resistant to a wide range of treatment options found success with low-dose naltrexone, described by her mom as “a miracle drug.”
A discussion of her case can be found here: A Small Victory (Low Dose Naltrexone)
However, since low-dose naltrexone has limited clinical research, it could be a challenge to get a prescription for it. There are no low-dose naltrexone pills produced and it must be made by a compounding pharmacy.