Inflammatory pain characteristics

Finally, it is well recognized that certain acute traumatic and chronic pain conditions are associated with a mixture of noiciceptive inflammatory and neuropathic pain. For example, tissue injury and a marked inflammatory response following laparotomy or thoracotomy initiates a somatic nociceptive component responsible for incisional and muscular pain, while peritoneal or pleuritic irritation is responsible for a visceral nociceptive component. Neural injury related to retraction or transection initiates a neuropathic component. Clinical pain complaint, intensity of symptoms, pain characteristics and choice of analgesic are related to the extent of inflammation, visceral versus somatic nociception, and neural tissue injuries. 

One of the first prodrugs, aspirin, is cleaved to the active agent, salcylic acid, in the liver as well as various other tissues. Despite the advent of numerous newer agents for the alleviation of the pain and inflammation characteristic of inflammatory diseases, aspirin remains the most widely used drug for this 108... 

Identify characteristics of the types of pain nociceptive, inflammatory, neuropathic, and functional. 

Pain episodes usually can be managed at home. Hospitalized patients usually require parenteral analgesics. Analgesic options include opioids, nonsteroidal anti-inflammatory agents, and acetaminophen. The patient characteristics and severity of the crisis should determine the choice of agent and regimen. 

Leukotrienes increase capillary permeability and serve as chemotactic factors for neutrophil granulocytes. As "slow-reacting substances of anaphylaxis," they are involved in allergic reactions (p. 326) together with PG, they evoke the spectrum of characteristic inflammatory symptoms redness, heat, swelling, and pain. 

Further experimental evidence for the involvement of SP in pain perception came from knock-out animals. Mice, in which the preprotachykinin A gene was disrupted, showed significantly reduced responses in tests that involved more intense noxious stimuli (Cao et al., 1998). De Felipe et al. (1998) disrupted the N receptor, and found the characteristic amplification ( wind up ) and intensity coding of nociceptive reflexes to be absent. NK receptor knockout mice show no changes in acute nociception tests. In contrast, SP and NKi receptor knock-out mice show reduction in responses to inflammatory stimuli. Nerve injury-induced mechanical but not thermal hyperalgesia is attenuated in NKi receptor knock-out mice, when inducing chronic neuropathic pain by unilateral ligation of the L5 spinal nerve (Mansikka et al., 2000). 

Similar serum enzyme elevations are found in polymyositis (A3, B4a, B20, D2, D17, E5, H7, KIO, M15, M18, Pl, P4, P5, P7, R15, S15, S26, T8, W12, W19), a nonspecific inflammatory myopathy sometimes associated with neoplastic disease but in general related to the collagen diseases and likewise responsive to corticosteroid therapy. The condition occurs at all ages in both sexes, may be acute or insidious with perhaps a normal erythrocyte sedimentation rate, may or may not be painful, or may be accompanied by an erythematous rash (dermatomyositis). Characteristically the earliest appearance of weakness is in the muscles of the pelvic... 

Characteristically the pain is deep-seated, positional, frequently nocturnal, and unresponsive to medication. The intensity of the pain varies from mild to severe, and does not usually correlate directly with the inflammatory process or other physical findings. Severe attacks last from several days to several weeks and may be aggravated by eating. 

Pain is not only one of the cardinal characteristics of inflammation, but the most significant one in clinical inflammatory disease it is often the principal target of anti-inflammatory treatment. However, pain is often of noninflammatory origin and may be relieved, regardless of its origin, by agents acting in several different ways. 

In humans, liquid silicone has been injected subcutaneously for cosmetic reasons. Granulomatous reactions have been reported to occur in some instances [14-17]. Similar reactions have been noted in two case reports following the rupture of silicone gel-filled breast prostheses [24,25]. Clinically, these reactions have the characteristics of an inflammatory response, i.e., redness, swelling, and pain. Histologic examination shows chronic inflammatory reactions, occasionally with the presence of refrac-tile material resembling silicone [24]. 

Often, the disease state may be divided into an acute (or inflammatory) phase and a chronic phase. During the former, there may be penile pain, even when flaccid, and there are often dynamic changes of the penile malformation. During the latter, pain (at least without intromission) resolves, and the malformation becomes stable in its characteristics. Contemporary series have reported a disappointing 13% or less rate of spontaneous regression without intervention (Gelbard et al. 1990 Kadioglu et al. 2002). 

The balance between hydrophobicity and hydrophilicity also determines the clinical characteristics of opioid analgesics, compounds that reduce pain without reducing consciousness (much). Dozens of opioids are in routine clinical use, and one reason so many are available is that they have different onset times and durations of action. This allows clinicians to choose the right one for a given circumstance. Most opioid drugs interact with a single type of receptor, the p-opiate receptor, which, like most cellular components, is lipophilic. Consequently, the primary determinant of onset time is lipophilicity, just as it is for local anesthetics and nonsteroidal anti-inflammatory drugs. 

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