Major Research Findings

Topical capsaicin application has been shown to reduce infarct size in experimental animal models. 11 The cardioprotective properties of topical capsaicin application could be related to its hypothermic effect. 11 Topical capsaicin has been reported to improve symptoms of cannabinoid hyperemesis syndrome. 4 Cannabinoid hyperemesis syndrome is a clinical disorder that has become more prevalent with increasing use of cannabis and synthetic cannabinoids, and which is difficult to treat. 4 Standard antiemetics commonly fail to alleviate the severe nausea and vomiting characteristic of the syndrome. 4 Interestingly, cannabinoid hyperemesis syndrome patients often report dramatic relief of symptoms with hot showers and baths, and topical capsaicin. 4 Topical capsaicin has been shown to have potential for reducing chronic itch associated with atopic dermatitis. 5 Chronic itch is an unpleasant sensation that triggers a desire to scratch that lasts for six weeks or more. 5 This is a major diagnostic symptom of myriad diseases, including atopic dermatitis for which it is the most prominent feature. 5 Chronic itch can be hugely debilitating for the sufferer, damaging in terms of both the monetary cost of treatment and its socioeconomic effects, and few treatment options exist that can adequately control it. 5 Topical capsaicin has been shown to be effective in treating neurogenic skin inflammation. 13 Neurogenic-mediated inflammation may be associated with several inflammatory skin diseases including atopic dermatitis. 13 However, age-dependent differences in neurogenic-mediated skin responses are not fully understood. 13 Topical capsaicin has been shown to have potential for enhancing the analgesic effects of morphine. 10 However, capsaicin alone is not superior to morphine alone in its analgesic effects. 10 Topical capsaicin has been suggested to be effective in reducing pain associated with osteoarthritis. 14 Topical capsaicin has been shown to potentially increase flap survival. 7 Topical capsaicin is a potential option for treating persistent pain in older adults. 3 Topical capsaicin is a potential option for treating pruritus in dogs with atopic dermatitis. 9 Topical capsaicin is a potential option for treating painful diabetic peripheral neuropathy in the feet. 12 Topical capsaicin is a potential option for treating peripheral neuropathic pain. 8 Topical capsaicin has potential for reducing cough. 6 Topical capsaicin, when encapsulated in alginate microcapsules, might reduce skin side effects. 1 Topical capsaicin failed to suppress cortical processing of CO2 laser pain in migraine patients. 2

Benefits and Risks

Benefit Summary

Topical capsaicin has shown potential to reduce infarct size, improve symptoms of cannabinoid hyperemesis syndrome, reduce itch associated with atopic dermatitis, treat neurogenic skin inflammation, reduce pain associated with osteoarthritis, treat painful diabetic peripheral neuropathy in the feet, treat peripheral neuropathic pain, reduce cough, and potentially increase flap survival. 11 4 5 13 14 12 8 6 7 Topical capsaicin is also a potential option for treating persistent pain in older adults. 3 It has also been suggested that capsaicin could enhance the analgesic effects of morphine. 10 It is also a potential option for treating pruritus in dogs with atopic dermatitis. 9 Encapsulation in alginate microcapsules could potentially reduce skin side effects. 1

Risk Summary

Topical capsaicin can cause temporary irritation and pain at the application site. 12 Skin redness, swelling, itching, and rash have been reported as side effects of topical capsaicin. 9 1 It has been shown that while capsaicin could enhance the analgesic effects of morphine, it is not superior to morphine alone. 10 Topical capsaicin did not suppress cortical processing of CO2 laser pain in migraine patients. 2

Comparison Across Studies

Similarities in Studies

These studies indicate that topical capsaicin has the potential to reduce symptoms of a variety of conditions. 11 4 5 13 14 12 8 6 One commonality is that topical capsaicin can cause temporary irritation and pain at the application site. 12 9 1

Differences in Studies

The studies differ in their focus of research, such as the condition being studied, the research methods, and the dosage and duration of capsaicin treatment. 11 4 5 13 14 12 8 6 7 9 1 The results of the effectiveness of topical capsaicin varied across the different studies. 10 For example, capsaicin could enhance the analgesic effects of morphine, but it did not suppress cortical processing of CO2 laser pain in migraine patients. 2

Consistency and Contradictions in the Results

These studies suggest that topical capsaicin has potential for reducing symptoms of a variety of conditions, but its efficacy can vary between different conditions and studies. 11 4 5 13 14 12 8 6 Additionally, topical capsaicin can cause temporary irritation and pain at the application site, and skin redness, swelling, itching, and rash have been reported as side effects. 12 9 1 These study results indicate that careful consideration of the individual patient's condition and risks is necessary when clinically evaluating the effects of topical capsaicin. 10 2

Considerations for Application in Daily Life

Topical capsaicin is a potential treatment option for a variety of conditions, but it can cause temporary irritation and pain at the application site. 11 4 5 13 14 12 8 6 Skin redness, swelling, itching, and rash have also been reported as side effects. 12 9 1 Therefore, it is crucial to consult with a healthcare professional before using topical capsaicin and to follow their instructions carefully. 10 It is especially important for pregnant or breastfeeding women, and individuals with pre-existing conditions such as heart or liver disease, to avoid the use of topical capsaicin. 2 Keep topical capsaicin out of reach of children. 14

Limitations of Current Research

These studies are primarily based on animal experiments and small-scale clinical trials. 11 4 5 13 14 12 8 6 Therefore, further research is needed to evaluate the long-term effects and safety of topical capsaicin. 7 9 1 Additionally, these studies suggest that the effects of topical capsaicin may vary based on the individual patient's condition and risks. 10 It is crucial to consult with a healthcare professional before using topical capsaicin and to follow their instructions carefully. 2

Future Research Directions

Larger-scale clinical trials are needed to assess the long-term effects and safety of topical capsaicin, as well as its effectiveness in various patient conditions and risks. 11 4 5 13 14 12 8 6 The development of new dosage forms and formulations that could enhance the effectiveness of topical capsaicin is also a desirable area for further research. 7 9 1 Further research on the potential interactions of topical capsaicin with other medications is also warranted. 10 2

Conclusion

Topical capsaicin is a promising treatment option with potential for reducing symptoms of a variety of conditions. 11 4 5 13 14 12 8 6 However, it is important to note that topical capsaicin can cause temporary irritation and pain at the application site, and skin redness, swelling, itching, and rash have been reported as side effects. 12 9 1 Therefore, it is crucial to consult with a healthcare professional before using topical capsaicin and to follow their instructions carefully. 10 Larger-scale clinical trials are needed to evaluate the long-term effects and safety of topical capsaicin, as well as its effectiveness in various patient conditions and risks. 2