CYCLOOXYGENASE INHIBITORS ACETYLSALICYLIC-ACID AND INDOMETHACIN DO NOT AFFECT CAPSAICIN-INDUCED NEUROGENIC INFLAMMATION IN HUMAN SKIN

Neurogenic inflammation is evoked by neuropeptides released from prima ry afferent terminals and, presumably, by other secondarily released i nflammatory mediators. This study examines whether prostaglandins migh t participate in the development of neurogenic inflammation in humans and whether cyclooxygenase inhibitors have any anti-inflammatory effec t on this type of inflammation. In healthy volunteers, neurogenic infl ammation was elicited by epicutaneously applied capsaicin (1%), after systemic pretreatment with acetylsalicylic acid, or topically applied indomethacin compared to pretreatment with saline or vehicle, respecti vely. The extent of neurogenic inflammation was quantified by planimet ry of visible flare size and recording the increase of superficial cut aneous blood flow (SCBF) with a laser Doppler flowmeter. Capsaicin-ind uced flare sizes and outside SCBF (both representing neurogenically ev oked inflammation) were unaffected by acetylsalicylic acid or indometh acin. Only the capsaicin-induced increase of inside SCBF was attenuate d by local pretreatment with indomethacin, reflecting the participatio n of prostaglandins in the inflammatory response of those areas which were in direct contact with capsaicin.