Topical analgesics are cream, gel or spray, when applied over the painful area, decreases the pain. They relive musculoskeletal pain in muscle or joints when applied locally over intact skin. The topical analgesics have local anaesthesia, counterirritant, salicylates or capsacin as constituent. Topical anaesthetics may be used to relive pain, so as to numb the area. They are applied over skin, throat, nose or eyes. Counterirritants are drugs when applied over the skin decrease the pain from the tissue beneath like joints and muscles. They obscure the afferent pain sensation carried by the nerves of deeper tissue, when applied over the skin of that tissue, like at the joints or muscles. It also dilates the vessels in the area, increasing blood flow. The examples of counterirritants are turpentine oil, clove oil, eucalyptus oil, camphor, menthol, capsicum. Capsaicin is so much power counterirritant that it can relive post herpetic neuralgia pain. By local application the side effect due to absorption in systemic circulation are minimized.
