Paresthesia-Dysesthesia in Polycythemia vera—Follow-up observations

Paresthesia-Dysesthesia in Polycythemia vera

Follow-up observations

A 71 year-old. man with polycythemia vera (PV) developed paresthsia-dysesthesia 7 years after the diagnosis of the disease. (http://tw.myblog.yahoo.com/ccshsu-clement/article?mid=5982&prev=6160&next=5902&l=f&fid=7) (Paresthesia= pins-and-needles sensation of the skin, dysesthesia= severe paresthesia that causes pain.)  It was found to be due to the food intolerance to chocolate and could be relieved by gabapentin. (In food intolerance, the amount of food taken is proportional to the degree of the symptom; and in food allergy, even a small amount of the allergen can precipitate serious reactions through immunologic response.) In the beginning, only chocolate was found to induce the symptom. However, 5-6 months later, peanut-butter or peanut was also noted to cause paresthesia-dysesthesia, and gabapentin (100 mg, one dose) relieved it. Further, in about one month, the paresthesia was also noted after hot shower or bath, akin to the classic description of “pruritus” in PV. It occurred within 30 minutes after the bath and lasted for about one hour. Because of the short duration of the paresthesia after the bath, no medication, such as aspirin or antihistamine, has been tested for the symptom. In addition to the hot bath, there appears to be some other unidentified factor(s) that causes milder paresthesia that could be alleviated by gabapentin.

The common element in the development of paresthesia in response to multiple factors (i.e. foods and hot temperature) several years after the diagnosis of PV appears to be the progress in the PV. There could be changes for the worse in the components in the abnormal platelet or other factors from the marrow cells. Further observation in other patients and laboratory research is needed to elucidate the phenomenon of the skin manifestation in PV.

A point that needs to be clarified is that paresthesia is apart from pruritus. Pruritus is relieved by repeated scratching, and perhaps by antihistamins; whereas paresthesia could be improved by gentle rubbing or touching over the skin and by gabapentin, a medicine for the neuropathic pain and seizure. This distinction suggests that different mechanisms are involved in the production of “pruritus” and “paresthesia”. In prior reports of skin manifestation of PV, it was described as “pruritus after hot bath”. In this case, “paresthesia” was noted after hot bath. It has been customary for many to include “paresthesia” in the category of “itching” or “pruritus”. It makes one wonder whether previous description of “pruritus in PV” was indeed “paresthesia”. A more precise observation and description is needed in the future.