For musculoskeletal pain, topical pain relieving gel patch has been proved to be as effective as oral medicine 1). In addition, compared to oral medication, 1) has fewer side effects such as gastrointestinal dysfunction, and has the advantages of being easy to use for patients with liver and kidney dysfunction. In addition, topical gel plaster exerts local anti-inflammatory and analgesic effects by applying it to the target affected area and absorbing the active ingredient into the systemic circulation system through the epidermis. There are "cold feeling" and "warm feeling" types of gel pastes in the Japanese market. What are the differences between them and in what scenarios? In this research article, we will take a look at the "difference between cold and warm gel pastes".

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▶  In a nutshell  ◀

Difference between cold feeling and warm feeling gel pastes=appropriate use according to pain.
First of all, "cold compress" and "warm compress" have the same analgesic components, and both belong to non steroidal anti-inflammatory drugs (NSAIDs), such as flurbiprofen, loxoprofen sodium, Methyl salicylate, ketoprofen, biphenylacetic acid, etc. That is to say, whether it is cold or hot, the analgesic effect is the same.
Although the ingredients are the same, patients can choose to use cold or warm sensations to alleviate symptoms based on their physiological state of pain.

According to the skin irritating ingredients shown below, the temperature sensation of the application site may vary between "cold compress" and "hot compress". Its components act on the skin, causing sensory excitement and expanding skin blood vessels.

Since L - Menthol acts directly on the nerves of the skin, it does not actually lower the body temperature. When L - Menthol acts on the skin nerve cold receptors, their reaction is the same as when the temperature drops, so you will feel cool. Although no similar effect was observed when taken orally, it can exert analgesic effects by stimulating the skin.

The Capsaicin contained in the pepper extract has the effect of skin thermal stimulation. Under normal circumstances, the temperature receptors in the skin only experience a burning sensation when subjected to thermal stimulation above 43 ° C. It can cause an increase in skin blood flow, which is visible during normal skin heating. There are also research reports that Capsaicin plays an analgesic role by desensitizing (stimulating the Sensory nerve so that it can no longer respond to other pain stimuli) 4).

After being injured by bruises, the affected part has a hormone called Bradykinin that acts and causes inflammation. As a result, "acute pain" occurs when the area becomes red, swollen, hot, and painful. For the pain caused by muscle tearing, "cold compress" can be used to remove excess heat from the affected area, reduce skin temperature, and promote swelling to subside.

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In addition, in the long-term "Chronic pain", Sympathetic nervous system excitation → narrowing of blood vessels, reduction of blood, production of painful substances → excitation of other Motor nerve → muscle tension, the same causes pain. If the affected area is stiff and Chronic pain, such as back pain or shoulder stiffness, "hot compress" can be used to improve blood circulation.

Source (Network)

The above content can be summarized as follows.
Acute pain: Inflammatory area with fever and swelling → Cooling and reducing inflammation → Using "cold sensation" type
Chronic pain: blood flow stagnation, muscle stiffness, pain aggravation → hot compress to improve blood circulation → use "hot feeling" type

The gel paste has a unique smell. Some people find it fresh, while others find it unbearable. In a study on the cooling sensation of Menthol, it is said that women's evaluation of the cooling sensation is often higher than that of men, although there is no difference between men and women in the sensitivity when using it. In addition, in a survey of patients using topical patches, people tend to choose "once a day, light and odorless topical patches".

However, simply following the patient's preferences may also have side effects. Since Capsaicin is fat soluble 4), it is easy to penetrate into the skin. Using Capsaicin may cause Contact dermatitis symptoms such as redness, itching, burning pain, etc. In order not to cause such dermatitis, it is recommended that patients use temperature sensitive gel plaster:

• When applying, wipe off the affected area of water and keep the skin dry.

• Every time the application area is changed, let the skin rotate to rest.

• Avoid prolonged application to the skin surface.

• Gel or cream substitutes are recommended for patients with allergic reactions.