Presence of neuropathic pain as an underlying mechanism for pain associated with cold weather in patients with sickle cell disease.

Less than 20 years after Herrick described the first case, the cold was proposed as having a role in precipitating pain in sickle cell disease. Numerous publications focus on weather changes, in particular exposure to the cold, and their association with vaso-occlusive (painful) episodes. Whereas several theories have been proposed to explain the association, a plausible hypothesis based on our current understanding of the pathophysiology of pain has not been offered. We hypothesize that the pain evoked by these weather changes are allodyinic (pain with stimulus not typically painful) and hyperalgesic (heightened pain with painful stimulus) responses due to the presence of neuropathic pain. This hypothesis represents a paradigm shift in understanding, as well as explaining at least some of the pain experience in sickle cell disease, and should be the impetus to further determine the characteristics of those patients who develop allodynia and hyperalgesia to cold weather. Whereas some researchers have suggested that those with sickle cell disease may have neuropathic pain, including a report from our own ongoing study [1], it has not been well accepted nor has it been applied in understanding pain associated with sickle cell disease. The conceptual shift and new understanding is important to develop preventive strategies, apply pain therapies new to the sickle cell population, and view pain in sickle cell disease in the context of a chronic disease.