Medication
Traditional analgesics The pain in Dercum’s disease is often reported to be refractory to analgesics and to non-steroidal antiinflammatory drugs (NSAIDs}. However, this has been contradicted by the findings of Herbst et al. They reported that the pain diminished in 89% of patients (n=89) when treated with NSAIDs and in 97% of patients when treated with narcotic analgesics (n=37). The dosage required and the duration of the pain relief are not precisely stated in the article.
Lidocaine An early report from 1934 showed that intralesional injections of procaine (Novocain®) relieved pain in six cases. More recently, other types of local treatment of painful sites with lidocaine patches (5%) (Lidoderm®) or lidocaine/prilocaine (25 mg/25 mg) cream (EMLA®) have shown a reduction of pain in a few cases.
In the 1980s, treatment with intravenous infusions of lidocaine (Xylocaine®) in varying doses was reported in nine patients. The resulting pain relief lasted from 10 hours to 12 months. In five of the cases, the lidocaine treatment was combined with mexiletine (Mexitil®), which is a class 1B anti-arrhythmic with similar pharmacological properties as lidocaine. The mechanism by which lidocaine reduces pain in Dercum’s disease is unclear. It may block impulse conduction in peripheral nerves, and thereby disconnect abnormal nervous impulse circuits. Nonetheless, it might also depress cerebral activity that could lead to increased pain thresholds. Iwane et al. performed an EEG during the administration of intravenous lidocaine. The EEG showed slow waves appearing 7 minutes after the start of the infusion and disappearing within 20 minutes after the end of the infusion. On the other hand, the pain relief effect was the greatest at about 20 minutes after the end of the infusion.
Based on this, the authors concluded that the effect of lidocaine on peripheral nerves most likely explains why the drug has an effect on pain in Dercum’s disease. In contrast, Atkinson et al. have suggested that an effect on the central nervous system is more likely, as lidocaine can depress consciousness and decrease cerebral metabolism. In addition, Skagen et al. demonstrated that a patient with Dercum’s disease lacked the vasoconstrictor response to arm and leg lowering, which indicated that the sympathicusmediated local veno-arteriolar reflex was absent. This could suggest increased sympathetic activity. An infusion of lidocaine increased blood flow in subcutaneous tissue and normalised the vasoconstrictor response when the limbs were lowered. The authors suggested that the pain relief was caused by a normalisation of up-regulated sympathetic activity.
Methotrexate and infliximab One patient’s symptoms were improved with methotrexate and infliximab (Remicade). However, in another patient with Dercum’s disease, the effect of methotrexate was discreet. The mechanism of action is unclear. Previously, methotrexate has been shown to reduce neuropathic pain caused by peripheral nerve injury in a study on rats. The mechanism in the rat study case was thought to be a decrease in microglial activation subsequent to nerve injury. Furthermore, a study has shown that infliximab reduces neuropathic pain in patients with central nervous system sarcoidosis. The mechanism is thought to be mediated by tumour necrosis factor inhibition.
Interferon α-2b Two patients were successfully treated with interferon α-2b. The authors speculated on whether the mechanism could be the antiviral effect of the drug, the production of endogenous substances, such as endorphins, or interference with the production of interleukin-1 and tumour necrosis factor. Interleukin-1 and tumour necrosis factor are involved in cutaneous hyperalgesia.
Corticosteroids A few patients noted some improvement when treated with systemic corticosteroids (prednisolone), whereas others experienced worsening of the pain. Weinberg et al. treated two patients with juxta-articular Dercum’s disease with intralesional injections of methylprednisolone (Depo-Medrol). The patients experienced a dramatic improvement. The mechanism for the pain-reducing ability of corticosteroids in some conditions is unknown. One theory is that they inhibit the effects of substances, such as histamine, serotonin, bradykinin, and prostaglandins. As the aetiology of Dercum’s disease is probably not inflammatory, it is plausible that the improvement some of the patients experience when using corticosteroids is not caused by an anti-inflammatory effect.
Read more about this topic: Adiposis Dolorosa, Treatment